1996 Chevy 6.5 Diesel Fuel Mileage

I just bought a 1996 Silverado 6.5 diesel 4x4 4D A.T. long bed with 213K on it. It is beautiful and super clean and loaded to the hilt, with an awesome customized sound system. Gave $432 for it. Spent another $1000 making repairs. Gets 12.5 mpg not pulling anything according to last fillup. I'm spoiled to 20+ mpg from my old "93 Cummins Dodge. I was wondering if any of you guys might know of some way to significantly improve the fuel mileage, like a chip or something. The inj. pump was rebuilt about 36K ago. Has 4 new glow plugs. Other 4 probably don't work. Runs like a champ. Thanks.
 
Can"t help you much with repairs, but mileage should be higher. My aunt has the same truck but with a manual transmission and is usually around 18mpg empty. She also has a 2wd regular cab that averages well over 20mpg.
 
It doesn't really need any repairs. It might just be that the additional weight of 4D cab plus the automatic tranny plus the additional weight and resistance of the 4WD transfer case, etc. plus the lower geared rear end all taken together will account for the low fuel mileage, and I should be grateful to be doing at least that good.
 
I generally get around 11 mpg towing 11,000lbs with my '93. You might want to post your question in the 6.5 section of The Diesel Place forum. Lots of people with extensive 6.5 experience over there. Good Luck
 
I have a '95 6.5 diesel 4x4, it will get 15mpg not loaded, but during the winter the mileage will drop somewhat. Hook onto my 5800 lb gooseneck trailer and the mileage drops to 10mpg with the trailer EMPTY. 7.5-8.5mpg with the trailer loaded. Worst mileage I ever got was 7.2 with 15,000 lbs on that trailer.
 
Is your truck a 1500 - 1/2 ton, 2500 - 3/4 ton or 3500 - 1 ton? Your trucks weight, tire size and axle ratio will affect your fuel milage.

Inside the glove compartment, on the floor of the box, there were some stickers with the option codes for your truck. If you can still read those stickers you can look up the codes and find your axle ratio.
 
http://www.62-65-dieselpage.com/

I have a chevy 1 ton with a 6.2 and this is the best website for all things 6.2/6.5 trucks. Click on books and order some of them. They have different volumes and cover everything from increasing mpg, more hp, and overall improvement of your truck.
 
Walter,
I used to have a 6.5 in my pickup, now powered by 5.9 Cummins (5 sp 4x4 4.10 gears).
With the 6.5, I actually got better mileage than the Cummins empty, about same loaded.
My experience with 6.2/6.5s (owned one for 25 year, worked on them in the military, is when power and mileage droop, and the engine idle is not crisp, the timing chain is worn and timing retards. Likely, your timing is now 9-11 ATDC. It needs to be 5.0 - 4.0.
One of the best, cheapest upgrades I did was to replace the timing chain with timing gear set sold on the diesel page. Set it once for the life of the engine. Times just like a 350.
The engine will run cooler, start better, rev better and mileage will improve.

Wayne
 
Put a set of the timing gears in a 6.2L (turbo'd) at 110K. Gears and turbo as same time. Truck ran great till 380K and it became a 11 o'clock truck. rings so worn it was hard to start. Ran it till 440K and traded it. When I was shopping for my current truck another salesman had sold mine, and I worked a good deal. Told them it had to be plugged in, or wait till 11am. Fine. Oil pressure was perfect, no leaks, ran like a raped ape.

point is those gears work, and make the engine last even longer and more power than timing chains.

Wayne
 
My brother has a 98 6.5 in a 2500 ext. cab 4x4. Has around 135K on it I think. He usually averages 19+ mpg, driving mostly 55 mph with the cruise set on country two lane roads.
 
The 6.2L/6.5L Detroit diesels were among the worst diesels ever produced. If your getting similar mileage out of a cummins and not beating it, there is something wrong.
Not trying to be a troll, so sorry if I'm coming off like that. I knew a guy very well who had one of those rigs. Complete POS, terrible mileage, gutless and constantly had to fix it.
If your truck is in as good of condition as you say, I would consider selling it and getting decent money while you can. Replace it with a Ford or Dodge diesel.
 
That is exactly what I intend to do. I never said I was getting similar mileage out of my "93 Cummins Dodge. I get 21+ mpg out of that truck. It's just getting a little tired after about a half a million miles, and the body is not so nice anymore. But in defense of this 6.5, it managed to hold up for 215K miles, some of that while pulling a 30' camper trailer. It still runs great, although not getting acceptable fuel mileage, and lacking the torque of my Cummins. If I could cure the mileage problem, I would keep it.
 
The 6.2 and 6.5 were the 4th worst and 3rd worst engines ever produced. Right behind the 6.0 and 5.7. However, there were a few good ones made. The early and late 6.2"s weren"t bad and the early 6.5(same block as late 6.2) weren"t supposed to be too bad. Compared to the 5.9, 7.3 or later on, the 6.6, they were all terrible though. We had a 91" 6.2 for 8 years and it never really caused a problem. The biggest problem with that truck was the damned 4x4 thermal actuator.
 
The laws of thermal dynamics are limited, and Cummins is a great engine, or I would not have pulled my 6.5L and replaced it with a 5.9L. However, that said, my mileage was good on the 6.2 and the 6.5L. Empty and loaded. By the time my 6.5 was pulled, it was no longer stock. I had lower-compression pistons, larger turbo, ported heads, with ceramic coating on exhaust passages and manifolds. It ran awesome. Simply not dependable. For those who spew the conventional rhetoric falsely, I will call you on it. A well tuned 6.5 would get good mileage. It was not designed to pull heavy, nor would it. My well tuned - overbuild 6.5 lasted JUST 44K. By no means will I endorse the 6.5. It is a piece of crap, but that piece of crap was capable of getting good mileage when the timing chain was not worn and it was tuned. My Cummins pulls awesome and get satifactory mileage. I could lie and say it gets better, but it gets good to great milege, but not awesome. Awesome would be 20MPG or better. Of course my Cummins is tuned. I could not be more pleased. My Cummins now has 380K on it, and still runs like a champs and my 1 ton will pull a much as my medium duty truck, but seriously - I like to stop with a load.

I have also owned one of those little VW pickups that 4400 were made in New Cumberland PA in the early 80s. All the little diesels get 50MPG, spew the conventional wisdom. Bullshippng. 43 tops. I have owned 9 of them. I re-engineer the one I own now, and struggled to get 50, but just ask around, they all got 50.

your statement is merely repeating what others have said, and does not help Walter at all with his decision. I personally did my conversion from 6.5 to 5.9 myself in 2004, and it is no small task, and for that model hard to do right. Simply, there is not enough room for a fan, radiator and an aftercooler. A minumum 2 inch cab rise kit is required to close the hood, and every cross-member has to be moved. DoAble, sure, more than one converted. Worth it , abosolutely. My truck drives great, and is very dependable.
Walter got a great deal, if I remember the price, and has not broke the bank to get it running. Obviously, like many of us, he does not have unlimited funds, and asked what can he do reasonably priced to have a dependable truck. Parroting that the 6.2/6.5 is the worst...Really, no help there. Yes you are a troll: PretendFARMER.


"The 6.2L/6.5L Detroit diesels were among the worst diesels ever produced. If your getting similar mileage out of a cummins and not beating it, there is something wrong.

Not trying to be a troll, so sorry if I'm coming off like that. I knew a guy very well who had one of those rigs. Complete POS, terrible mileage, gutless and constantly had to fix it.

If your truck is in as good of condition as you say, I would consider selling it and getting decent money while you can. Replace it with a Ford or Dodge diesel.

This post was edited by PretendFarmer at 05:41:09 11/13/13.
 
No matter the diesel engine, mileage is dependant on gearing. The early 5.9L Dodge trucks had 3.07:1 gears and broke 20MPH, the uprated engine went to 3:54-1 with OD and stayed above 20. But 4:10 gears designed for towing mathematically 20 is hard to get.
I think if, and I mean if I ran 45MPH, for a full tank, sure 20 is going to happend, but not at acceptable speeds.
My old Cummins Chevy is now a farm truck. Would NOT think twice about a cross country trip, even if its a 93 model, but for mileage, I drive something else.

Walter, if the 6.5 starts well,has good oil pressure, replace the chain or install the gears and with just over 200K, another 100 is possible if not more. If you are not pulling 12K or more, it will do ok. The injectors on the 6.5 are very forgiving and a bottle of cleaner is tune up enough. Hydraulic llfter, and most everything adjust similar to a 350. After 94, the injector pumps and PDM cooling issues cause problems if pulled heavy. Used as a pickup for errands, normally fine (must be with 200K).
Sounds like you got it at a reasonable price. I wish you well.

Wayne
 
"Hydraulic llfter, and most everything adjust similar to a 350."


UMMMM... the 6.2's and 6.5's have a NON=adjustable valvetrain.
 
Hydraulic lifter, COMMA, and most everything adjust like a 350.

My comments have been to Walter how to make something out of the truck he bought. I suggested the timing chain or timing gears.

Sure, it would be easier to just tell him, the engine sucks, and offer no help.
 
Walter,
IF, and I repeat IF, you do not intend to tow a lot with this truck, a simple DIESEL engine replacement is the 3.9L Cummins.
Bell-housing adapter plates and flywheels are available to match GM trannys ( I have one). Premade motor-mounts are availbable for a 96 chevy. If auto, your TPS will work. No frame cross-members need moved, tranny stays the same.
Google Tennessee Diesel Conversions and there is a guy who specializes in putting 4BTs in other stuff. Mounts, and other hardware.
Pleaty of these 4BTs available. With 4:10 gears, you may need a larger tire or lower gear set.
And with Cummins B-Rated performance. A 125-130 HP 4BT will deliver more useable power than the 6.5L. Near Bullet-proof. A mere turn of the star wheel or Gov RPM kit will bring more UMPHF.
Since the engine is shorter than the 5.9L, the hood will close without a body lift kit.
You have not really describe the trucks condition, rust, etc, but if you cannot make something out of the 6.5, the 4BT is a bolt in fix. Be advise you will know it is a Cummins, as the noise is louder than the 6.5.
I put one in my old 68 Bronco, and it will spank the 302 gasser, and my mileage is like it has a 6 cyl gasser. I am currently pulling my GM (T400/465)tranny to install a Ford ZF five speed.
you have options.

Wayne
 
I never heard of a 3.9 liter Cummins. I do intend to tow loads up to about 20,000#. I do not want an automatic tranny, unless it might be an Allison. This truck, like I said, is in super clean, super nice condition. If the noise of a 3.9 is louder than this 6.5, I wouldn't want it for that reason if for no other. This 6.5 is the noisiest engine I have ever seen. We are currently putting a "93 5.9 Cummins into a "94 Chevy dually with an NV-4500 5 spd. tranny. Can't wait to get it on the road.
 
Wayne, just for my own information, as I would like to put an HX-40 on my 6.5 (DB2 pump). What failed in your tuned 6.5? Did you install a forged crank or hard-block it? Thanks for your time.

Mark
 
If it's a single rear wheeled truck and turns around 2200 RPM at highway speeds - empty on a flat highway ought to be in 16-17 MPG range.

In regard to the 3.9 Cummins? Great engine but it makes around the same power as a non-turbo 6.2 diesel or a 305 gas engine. Quite a bit less then a 6.5 turbo.

The 6.2/6.5 certainly are not the "worse" diesels ever built but they ARE light duty as compared to a Cummins 3.9/5.9 or IH/Ford 7.3. The engine was originally designed to make the power of a 305 gas engine. Now? The newest 6.5s made for the military are much stronger then the ones GM was making. Blocks are stronger, heads heavier, and forged-steel cranks available.

I've got an 86 Blazer with a 6.5 turbo. Has a small RV body on it. When it had 3.08 axles, no turbo, and 15" tires it got a best of 16 MPG. When I changed to 4.10 axles, added a turbo, and 16" tires - it certainly pulled hills better and still gets a best of 16 MPG.

My 1982 K10 4WD with a 6.2 diesel and 3.08 axles and four speed manual overdrive gets a best of 23 MPG.

My 1983 K10 with a 6.2 diesel, 3.08 axles and TH400 auto gets a best of 19 MPG.

My 1986 K5 with 6.5 turbo, 4.10 axles and a 4L60 trans gets a best of 16 MPG.

My 1983 Ford F250 4WD extended cab with a 6.9 diesel, 4.10 axles and a C6 trans gets a best of 13.5 MPG.

My 1994 Ford F250 4WD extended cab with a 7.3 turbo IDI, E40D trans and 4.10 axles gets a best of 17 MPG.

My 1992 Dodge W200 4WD extended cab with a 5.9 turbo-intercooled Cummins, 3.50 axles, and Getrag 5 speed manual gets a best of 20.5 MPG.

My 1988 K5 Blazer with a Cummins 3.9 turbo, 3.08 axles, and TH400 trans gets a best of 24 MPG.
 
There's always going to be someone out there who can say something good about anything but....
I will stand by what I said. The 6.2/6.5L is one of the worst diesels ever produced. Very problematic/unreliable and underpowered.

And Wayne. If I am the troll here, what does that make you? I never bashed anyone but you went right ahead and bashed me.
This is a discussion about the GM diesels. Plain and simple there will be various opinions about it.

Now with that said if I "Gave $432 for it. Spent another $1000 making repairs" I would be plenty happy to drive that. Overall you got a truck for less than $1500.

The idea of a 4BT is a good one but not for towing 20,000.
The 4BT Cummins is a great 4 cylinder diesel. The power potential is up there but you better have deep pockets if you want good enough power to tow alot. If you are in need of a truck that can tow 20,000 lbs, I would advise you look elsewhere. By the time you get your older GM diesel to do it you could have a Duramax and way less headaches.
 
(quoted from post at 01:36:57 11/15/13) I never heard of a 3.9 liter Cummins. I do intend to tow loads up to about 20,000#. I do not want an automatic tranny, unless it might be an Allison. This truck, like I said, is in super clean, super nice condition. If the noise of a 3.9 is louder than this 6.5, I wouldn't want it for that reason if for no other. This 6.5 is the noisiest engine I have ever seen. We are currently putting a "93 5.9 Cummins into a "94 Chevy dually with an NV-4500 5 spd. tranny. Can't wait to get it on the road.

That is a good combination but you should know that:
The NV4500 is rated for max torque of 460 ft-lbs. Not much aftermarket to help there. There are clutches that hold more but the gearbox is what it is. There is the fifth gear nut issue.
Plenty of people run that tranny with no issues but that depends on driving habits. A NV4500 behind a tuned cummins wont live long under abuse.
In stock form the Dodge 47re leaves much to be desired. Aftermarket upgrades make it a great transmission. I was going to convert to a manual, but spent way less to upgrade my Automatic and its a whole new rig.

FYI, I have built up my stock 47re for about $1000 and it will handle about 600ft-lbs with a converter that will handle 850ft-lbs.
It sounds like your on the right track in terms of this cummins engine in your GM. Might have fitment issues tho.
 
jdemaris, I really appreciate all the info. I really think that the main difference in fuel mileage between my Chevy and your fleet is the combination of the 4WD tranny and the weight of this truck. This is a full 4 door crew cab, with a long bed, heaviest truck I've ever owned. It would be an ideal candidate for a Cummins conversion. But I'm already doing that to a "94 Chevy dually, so I'm going to sell this one. Thanks again.
 
Thanks PF. I know I got a great deal, but I'm looking forward to getting the "94 Chevy Cummins conversion finished. I miss the power and the fuel economy.
 
Pretender,
I started the 4BT tread, with IF Walter is not going to tow. Certainly you read that. It is hard not to see the clarity of If you are not going to tow. Apparenty, Walter does intend to tow. Note, again the word IF.
I made recommendation to correct mileage and potential for repower. I told Walter he had options.
What is I not do was repeat very close to the words of another poster, offer an opion without any formation basis (formation basis is things such as I owned one, I fixed one by doing this or that...) But your posting did just that, offer an empty opinion.
Yes you are a Troll. Your caliber on forums are internet mechanics. They repeat the postings of others, quibble and derate posters who attempt to offer advice. Offering the repeated advice of others, taking no risk in suggesting or advising the post initiator. I know there is another person on the other end of the post when you drop and opinion like you did, and I know you even have feelings. Stop being an internet mechanic. Such advice is the worst, printed but do not qualify it with experience, just that you read, you interpreted, and want to pass on like it is important, that such and such is a piece of crab, worst ever made, gets the mileage of a gasser, and just junk it, scrap, get rid of it.
Sorry for my rant, but internet mechanics (Trolls) get me going.
Now for Walter. If you are involved in a repower of a 1994 with a 5.9L, don't your already know the answer?
 
I see this topic from July 2013. Did not read it then.

Walter Buller 08-06-2013 21:00:30 99.195.174.231
I know a man who owns a 1996 Silverado 4D Club Cab 4WD w 250K on the 6.5 diesel, automatic w OD. Straight body. Clean interior. Gooseneck hitch in bed. Used it to haul around his 33" camper. Says he got 14mpg. He parked it 4 years ago when he moved. Been in same spot ever since. Rats built a nest on top of motor & chewed some of the wiring. I"m considering using it as a backup for hauling tractors if and when my "93 Dodge w a 5.9 Cummins w 400K on it ever quits. I"m thinking the Dodge body will fall apart before the motor quits. Maybe I could transfer the Cummins motor to the Chevy, and put .355 gears in the rear end to improve fuel mileage. What do you guys think about this, and what do you think would be a fair offering price?
farmer boy 08-08-2013 12:25:24 199.167.109.42
Re: 1996 Chevy 6.5 in reply to Walter Buller, 08-06-2013 21:00:30
I don't think a 6.5 is much of a backup for a 5.9. It would be expensive to mate the engine to the 4L80E, though not impossible, and if the engine is stock, it shouldn't overpower the transmission. Your best bet is to get an NV4500 and put that in. The only gears that are much good for a (that) diesel are 3.73 and 4.10. Go higher than 3.73 and you'll run out of power, lower than 4.10 and you'll run out of rpm's. Different rear gears won't do much for mileage while towing, but it would make a difference at higher speeds when not towing.

Walter Buller 08-09-2013 06:12:00 184.156.166.153
Re: 1996 Chevy 6.5 in reply to farmer boy, 08-08-2013 12:25:24

Thanks farmer boy. I think I'll offer the seller scrap price, maybe $500, take it or leave it, and plan to leave it like it is, with no conversion. If I manage to get a little use out of it before scrapping it I'll be ahead of the game. It's a shame though. It's a real clean, good looking truck.

FC Andy 08-07-2013 13:22:01 74.126.84.52

Re: 1996 Chevy 6.5 in reply to Walter Buller, 08-06-2013 21:00:30

I have my doubts about him pulling a 33 foot camper and getting 14 mpg... Although, I have been getting around 12 with my gooseneck and a 5,000 tractor on the deck (total trailer weight of about 10,500 lbs.)
I think I'd look into a wiring harness for the truck first, unless the wiring damage is limited to only a FEW wires. You're looking at a money pit no matter which way you go. The Cummins Conversion is popular, I think everything you need can be bought, but won't be cheap. Then you're putting a 400,000+ mile motor in a truck...Of course, we all know what a new truck costs. -Andy
T in NE 08-09-2013 20:02:02 75.239.200.217
Re: 1996 Chevy 6.5 in reply to FC Andy, 08-07-2013 13:22:01

Roll fresh mains in her, new oil pump, tab the KDP, and it'll be good for another 400,000. 366 governor spring and timing spacer from H&S for drivability. The rest of the truck is a whole nother matter.
 
Walter,
My 93 Chevy 4x4 started its life as a 6.5 with 5 speed, & in 2004 I put a 5.9L out of an International rollback in it.
I started with the 93 NV-4500 and the low 1st gear was useless with the cummins, so I traded it for a 96 NV4500 with taller granny.
Bottom line, as you know if you are helping with that 94, every cross-member has to be moved, rear shaft shorten, front shaft lengthened. Bell housing choices for the NV4500 are out there.
What I came away with is a truck that today runs like new, drives great, but being a 93 is ready for paint.
My old chevy is still used on the farm. It not only will tow 20,000 it will tow more. I once took it across the scale wondering just how overweight and my gross was 28K. But unless you do something to the brakes, your engine and tranny won't be the limit, but the brakes. I have not had NV-4500 problems, clutch does not slip. Sweet drving truck.
I have 4:10-1 gears. 84 MPH is tached out on the 5.9L that only turns 2550. Mileage is best 18-19 empty, 15-16 pulling empty trailer and worst pulling has been 12-13. Compare that to my GMC Topkick, and I tow with the Chevy when I can. But I love the way the Topkick stops.
5.9 dodge bell housing parts and NV 4500 can be comed by often with deals as good as yours.
You are also going to have to find some 93 or earlier cab parts, accellorator pedal, cluch pedal, etc.

Again, good luck.

BTW, I pulled the same weights with my overbuilt 6.5 on steroids. And """If"" I had weighed out lock tabs for my connecter rods, and balance them with the engine, it may still be running. I solved the cooling issues, with the 6.5, found HP & torque comparable, and it would actually run circles around the Cummins, but after all that $$$, to drop an connector rod at 44K (locknut came off stud) I got out of that engine line. So I sold the engine by part, by part and paid for the Cummins, and 4 months later started driving it. Today there is a lot more info on conversions than in 94.

Again, good luck. You have read your options many times. Good luck.

Wayne
 
My 1986 K5 4WD Blazer has a mini-motorhome body on it and weighs 6600 lbs. It has 3/4 ton axles, wheels and tires and a cast-iron transfercase. Weighs the same or a little more then your truck and mine probably has more wind-resistance due to the RV roof. The 16 MPG I get is a bit of a disappointment. Especially with diesel costing $4.20 per gallon and gasoline $3.49. That's why I starting using a Toyota RV with 1 ton running gear and a dually rear. It weighs 5600 lbs. and also gets 16 MPG - but the gasoline is a heck of a lot cheaper then diesel.
 
I'd rate the entire line of Oldsmobile diesels as
the worst ever offered for car and truck use -
especially the early 5.7s. Cast-iron cranks
breaking, head gaskets failing, injection pumps
seizing, etc. I was working on them when they were
new.

2nd to that I'd rate the GMC line of Toroflows as
pretty bad diesels considering they were intended
for heavy use.

In regard to the Detroit-Diesel designed 6.2s and
6.5s? They were originally intended as direct
power replacements for 305 gas engines and for
that - they worked well. In a pickup truck they'd
get 20 MPG instead of 14-15 AND diesel fuel was
cheaper then gas back then. Other then some minor
head-gasket problems in the first year engines
only (1982)they did pretty well in light use. Once
people starting using them in 1 tons, or 8000 lb.
RVs and step-vans - they did not fare very well.
Especaially with turbos added and fuel delivery
turned up.
The new 6.5s made today (Optimizer 6500) are
pretty rugged, compact, and lightweight but they
cost a fortune. Still in use by our military.

Considering the fuel crunch in this country when
the 6.2s were first introduced - they did a good
job with what they were first intended for. GM was
the only company offering diesels in full size 1/2
tons. My 1983 plow truck has 220K hard miles on
it and has never skipped a beat. Worst part of it
was the original 700R4 trans - not the engine.
Once a TH400 got swapped in along with a
mechanical modulator kit - it's been a great
truck. By today's standards - maybe not all that
impressive. By 1983 standards? Very impressive
considering it can get 20 MPG.
 
Thanks WayneB and PF. I already have the bell housing to connect the Cummins to the NV-4500 that came off of a Chevy 3500. It came from Advanced Adapters and bolted up fine. Cost over $300. And we already raised the cab 2" and acquired the right pedals. Now we just have to set the motor mounts and start hooking everything up. I've decided to take your advice and just sell the 6.5 Chevy. No amount of tuning is likely to give me the power and fuel economy that I already expect from the stock "93 Cummins, having driven one for 8 years already. Plus one of the nicest things about that Cummins is that it only takes one battery and will crank in the coldest weather without the block heater plugged in.
 
When I converted my chevy in 2004, there was little guidance, and I winged it. I hung an aftercooler under the bumper sloped back like the plate. It worked and I just kept driving it, and still. I have recently bought a used CK comlete radiator front support, and a Dodge Cummins aftercoler. My intent is to imbed the intercooler into the radiator support, take out the cross support rods, and cut and mig as necessary to make the aftercooler fit in front of the radiator. I still want my AC to work, like it does now. Radiator is OEM.
As is, the Dodge fan won't fit between engine and radiator. I used a short spacer and 18" flex fan. Obciously, it works, but I want more.
I have found the shortest cummins electic fan/clutch setup. I could always buy the clutch, but fans were obsolete NLA. My setup came off a 4BT "bread truck" complete with bracket.
I plan to pull my engine and do a gasket overhaul, replace, front & rear main seals, and service the engine vent. My truck is starting to age, so my steering gearbox will get replaced, and I intend to add a few bolt holes on the bottom of my bellhousing to make the setup better. And mahe the setup cleaner.
Parts are falling out everywhere now, but in 2004, dodge pickup engines and clutch bellhousings cost as much as a running truck.
I never touched my govenor other than advance the throttle plate 10mm tighten it down, which took my setup up towards 300+ HP, My boost pegs about 36PSI and my pyrometer is cool compared to the numbersI see reported on forums, likely because of 2550 max rpms. To this day, have never needed my heater grid. I run 2 optimas and the largest 00 welding cable for starter and grounds. I use a 21SI truck alternator.
After the gasket overhaul, she gets painted. For a 20 year old truck, this is par for course maintenance.
BTW take out the electric fuel pump. It will actually act as a power restrictor. Consider running copper larger lines tank to engine. When I ran larger lines, there was a seat of pants extra torque felt pulling hills. I also dropped my fuel tank and replaced the sock.
Brakes. Chevy 1 ton brake weight rear valves help, you actually use the shoe loaded and don't go thru the window empty.
Tires. Unfortunately, the 235LRE 16 tires are the tallest, and should match your speedo, and the cummins likes a taller tire. work well pulling.
My Cummins 5.9L 12V is bulletproof. No regrets in replacing the 6.5.
Wayne
 
There's a flip flop story if I've ever seen it.

Pointing out that the 6.2 was a direct replacement for the gutless 305 just shows how clueless the engineers were. Why would you as a company do that while Ford and Dodge were producing what they did? Stupid decision making there...

The Optimizer 6500 is a very acceptable diesel engine. With that said, I still choose a Cummins any day. If GM had produced that diesel(or something comparable for the time) from day one instead of the embarrassment that they did, GM might be viewed in a whole different light today.
 
Just the opposite. GM was genious in being the first to put a diesel in a light duty pickup in 81.

I bought an 82 K10 4x4 SP, auto, loaded, and that 6.2 was great, problem free till I sold it. But it was in a 1/2 ton, built for mileage. I turbo'd it, and it ran strong. I pulled a 29' TT camper with it. Pulled car trailers. I took that truck to Germany, and ran it on the autoban, all out. Bulletproof but light duty. I put a re-calibrated injector pump on it that turned 4100 RPM, and it REALLY ran great. Suprise a buddy on the autoban with a 85 Vette. Really liked that truck.Owned it for 14 years. Again as good as it was, it was light duty.

In 1984, GM sold the military on the 6.2 powered HMMWV and that's history. The HMMWV unfortunately today is still powered by it, and it has the longevity in the HMMWV of ice-cream in South Arizona.

Dodge took a tractor engine and introduced in about 1986 a 160HP/400TQ quiet little engine, in their 3/4-1 ton-- that 'was at-once' loved.

Ford in 1985/1986, thereabouts, but the 6.9L Internation in their pickups (3/4 larger) not so beloved, but morphed to the 7.3, to be sworn by.

Believe it or not in 1993, GM owned the HP ratings with the 6.5 intoduced in 92. But Ford and Dodge spanked GM in 94, which was the first year for electronic pumps on 6.5s, and 95/-97 Dodge and Ford uprated their engines with aftercoolers, etc, while GM flubbed along, till the Duramax was introduce.

Just think how much much money GM has made owning the 6.2/6.5 as long as they were in production and owning the Duramax vs bidding for an engine. Fleets were powered by these cheap engines.

GM spanked the market when they introduce the Allison 1000 with the Duramax. Genius.

GM did not tuck their tail and hide, from the 5.7L diesel debackle, they made a killing with the 6.2/6.5s. If diesel engines are too great, the engines last longer than the truck. GM married longevity with body, and move the market. Diesels junked with the truck. How many 350s were removed from boats and replaced with 6.2/6/5s. Many. Look up Peninsular Diesel.

Personally, I thought Dodge shaped the pickup truck history when they switched fromt the 93 square front ends to the retro curved fenders we see today. And they killed with the Cummins. But from a market prospective and profits, the engine lasts too long and simply is too good for the truck.

I say all the above in gest, whereas the timelines are close if not factual.

Government Motors / Genius Motors???

GM may be flawed to the point of genious.
 
(quoted from post at 18:22:02 11/18/13) Just the opposite. GM was genious in being the first to put a diesel in a light duty pickup in 81. [b:dfaeb776d3]I am more talking about the late 80's and up time frame. I guess I could've been more specific.[/b:dfaeb776d3]

I bought an 82 K10 4x4 SP, auto, loaded, and that 6.2 was great, problem free till I sold it. But it was in a 1/2 ton, built for mileage. I turbo'd it, and it ran strong. I pulled a 29' TT camper with it. Pulled car trailers. I took that truck to Germany, and ran it on the autoban, all out. Bulletproof but light duty. I put a re-calibrated injector pump on it that turned 4100 RPM, and it REALLY ran great. Suprise a buddy on the autoban with a 85 Vette. Really liked that truck.Owned it for 14 years. Again as good as it was, it was light duty.

In 1984, GM sold the military on the 6.2 powered HMMWV and that's history. The HMMWV unfortunately today is still powered by it, and it has the longevity in the HMMWV of ice-cream in South Arizona.

Dodge took a tractor engine and introduced in about 1986 a 160HP/400TQ quiet little engine, in their 3/4-1 ton-- that 'was at-once' loved.

Ford in 1985/1986, thereabouts, but the 6.9L Internation in their pickups (3/4 larger) not so beloved, but morphed to the 7.3, to be sworn by. [b:dfaeb776d3] As gutless as they were, there are plenty of people who I've known, who loved the old 6.9's. The 7.3's are a great engine. [/b:dfaeb776d3]

Believe it or not in 1993, GM owned the HP ratings with the 6.5 intoduced in 92. But Ford and Dodge spanked GM in 94, which was the first year for electronic pumps on 6.5s, and 95/-97 Dodge and Ford uprated their engines with aftercoolers, etc, while GM flubbed along, till the Duramax was introduce. [b:dfaeb776d3]They may have had the top numbers, but they still had problems that Cummins owners wouldnt. In addition peak numbers dont mean everything. A stock 1997 Cummins truck would haul anything you hook to it. And thats with 180hp.[/b:dfaeb776d3]

Just think how much much money GM has made owning the 6.2/6.5 as long as they were in production and owning the Duramax vs bidding for an engine. Fleets were powered by these cheap engines. [b:dfaeb776d3]Just think about what possible profits they could've made if their engine was more like Ford's 7.3, and they owned it?[/b:dfaeb776d3]

GM spanked the market when they introduce the Allison 1000 with the Duramax. Genius. This is quite debatable. The Allison 1000 gets too much credit.
[b:dfaeb776d3] I have seen as many of those in the shop, as I've seen Dodge Cummins with the 47re's. Except, the 47re is cheaper and easier to upgrade[/b:dfaeb776d3].

GM did not tuck their tail and hide, from the 5.7L diesel debackle, they made a killing with the 6.2/6.5s. If diesel engines are too great, the engines last longer than the truck. GM married longevity with body, and move the market. Diesels junked with the truck. How many 350s were removed from boats and replaced with 6.2/6/5s. Many. Look up Peninsular Diesel.

Personally, I thought Dodge shaped the pickup truck history when they switched fromt the 93 square front ends to the retro curved fenders we see today. And they killed with the Cummins. But from a market prospective and profits, the engine lasts too long and simply is too good for the truck.

I say all the above in gest, whereas the timelines are close if not factual.


Government Motors / Genius Motors???

GM may be flawed to the point of genious.

My answers are in bold.
All in all, I really do respect your point of view. Just at times, I disagree.
 
We may agree.

WayneB said: (quoted from post at 18:22:02 11/18/13) Just the opposite. GM was genious in being the first to put a diesel in a light duty pickup in 81."
PF- I am more talking about the late 80's and up time frame. I guess I could've been more specific.
WB- The Army bought over 200,000 Hummers, 65K CUCVs, and they each have multiple engine (av 1 every 3 years) - pure genius to sell the military that power plant (I don't like it in the HUMMER and the JLTV will be a better diesel).
WB-"Ford in 1985/1986, thereabouts, but the 6.9L Internation in their pickups (3/4 larger) not so beloved, but morphed to the 7.3, to be sworn by."
PF- As gutless as they were, there are plenty of people who I've known, who loved the old 6.9's. The 7.3's are a great engine. WB-we agree, but the 6.9 was not as loved as that quiet humming little 5.9L in the Dodge, reputed to pull stumps.

WB - "Believe it or not in 1993, GM owned the HP ratings with the 6.5 intoduced in 92. But Ford and Dodge spanked GM in 94, which was the first year for electronic pumps on 6.5s, and 95/-97 Dodge and Ford uprated their engines with aftercoolers, etc, while GM flubbed along, till the Duramax was introduce.
PF - They may have had the top numbers, but they still had problems that Cummins owners wouldnt. In addition peak numbers dont mean everything. A stock 1997 Cummins truck would haul anything you hook to it. And thats with 180hp.
WB-read again. In 1992-1993 GM was the TOP HP truck, like said above, but in 1994, Dodge and Ford Spanked GM. To compare a 1997 Dodge to a 1994 GM means we both agree and say the same thing... From 1994 to the introduction of the Duramax, GM was a toothless meat-eater.

WB - GM spanked the market when they introduce the Allison 1000 with the Duramax. Genius."
PF -This is quite debatable. The Allison 1000 gets too much credit. I have seen as many of those in the shop, as I've seen Dodge Cummins with the 47re's. Except, the 47re is cheaper and easier to upgrade.
WB - But GM forced Ford and Dodge to a new transmission and it permitted a pickup with 3:73-1 to pull like it has 4:10-1 - 4:30s and get great mileage still. GM forced their hands. I don't own an Allison - and won't try to pull with one, I prefer manual trannys. but I have to hand it to GM to force another new tranny on the market.

Today, hats off to Dodge for a truck rated to pull 30K. Hats off to Dodge diesel truck with great mileage again.

So this is my opinion on why it will be slow or never before we see a half ton or a compact truck again with a diesel, or for that matter a hybrid with a diesel. They last too long.

Say what you want about that terrible 6.2 and terrible 6.5, lots of them were sold and lots of them junked, which permits more new trucks. My 6.5 block was stripped and went to either scrap metal or as a boat anchor. Because I was in the military, and in military maintenance, I bought one early on, learned everything possible about them, tweaked them to their limit, own one or the other for 25 years and renounced them, and stood in numerous Army level briefings and in AM general meetings and blow by blow told them what was wrong with that engine, at first they fixed some of the problems and now, doom it to history and all the while made money on it.
For every HMMWV engine the govt uses, its about $4-5K profit to AM General, and that turd will be out there till 2032 or 2035.
You can hate them or recognize the slimy genius they are.
 
Thanks Wayne. We were looking at it today, trying to figure out how to get enough room for the radiator and fan. The back of the motor is already pushing against the firewall. What is the year model of your Chevy? My "94 has 37" between the firewall and the top of the front radiator support. We even thought about busting through the firewall to get more room. Would you mind going into a little more detail about how you solved that problem on your conversion, the spacer, flex fan, and so forth? I never heard of a flex fan.
 
My buddy's dad had a mid 90's Suburban 4X2 with an automatic and overdrive. We loved it. It got high 20's coming back from Florida. My gramp's 6.2 got 25mpg with 3.42 gears and a 700R4.
 
The Suburban was pretty new. They probably got rid of it at 100,000mi. The 6.2 had 200,000mi on it and didn't use hardly a drop of oil. If you could keep glow plugs in it, the thing ran and ran. It didn't win drag races, but it was good transportation and fun off road with it's light axles and limited slip rear. It was highway yellow with brown seats. Really stuck out.
 
I've had four Suburbans with 6.2 diesels. The highest any of ever got on a long flat highway was 21 MPG.

My 1988 GMC 3/4 ton 4WD Suburban with a 6.2 HD J-code, a T400 and 3.73 axles got a best of 18.5 MPG.

My 1987 Chevy 3/4 ton 4WD Suburban with a HD J-code 6.2, T400 and 3.73 axles did exactly the same. 18.5 MPG.

My 1991 Chevy 1/2 ton 4WD Suburban with a LD C-code 6.2, 4L60 trans and 3.42 axles got a best of 21 MPG.

My 1992 Chevy 1/2 ton 4WD Suburban with a J-code 6.2, Banks turbo, 4L60 trans and 3.08 axles got a best of 19.5 MPG.

Note all my Suburbans were driven in NY at 1600-1900 feet elevations. When my son took my 3/4 ton Suburban to Colorado at over 6000', mileage and power dropped like a rock. Went from a best of 18.5 MPG down to 14 MPG. He later had to add a turbo to it just to pass the Colorado smoke inspection.
 
I disagree. GM first had the 6.2 developed to offer
a more fuel efficient power replacement in a light
truck. It was done in response to the 1979 oil and
energy "crisis" in the USA. The new 6.2 was ready by
1981 which was pretty quick. Ford never targeted
the 1/2 ton class with the 6.9 and 7.3. Dodge tried
it for one year in 1977 or 78 with a Mitsubishi 6
cylinder and then gave up on 1/2 ton diesels.
 

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