O/T - 98 Cadillac engine shot - what next ??

98 DeVille Concours, 105,000 miles - excellent condition, EXCEPT - engine overheats quickly.

Dealer says engine shot - both heads "bad" due to overheating. Car belongs to step-daughter and husband (I know I'm only getting part of the story) Dealer wants $4-5K for an engine replacement. Blue book says the car is worth about that.

What options do you guys recommend? I'll listen to all of them.

I assume it's the Northstar engine. Those are very expensive to do that kind of repairs on. Have you looked for a good used engine for it? Unless you're inclined to try to repair it yourself, or have a friend who would try it, that's what I would advise you to do.
Good Luck and God Bless

What engine is in the car? 4-5k for the swap is high. Do some shopping for a replacement engine yourself through Carquest or Napa. Find a reputable mechanic to do the swap for you. Dealers are to high, but I would get a second opinion before you do a swap. Had a local couple was told the same thing. The engine was bad because it overheats, blah, blah, blah. The problem was the water pump was out, cost less than 300 bucks to fix, the car has been on the road with no problems for the last two yrs. Be careful do your homework.

They overheat then your head gaskets are shot or maybe that's what caused it to overheat ?

When you remove the heads on those you have to put timeserts into all the bolt holes as they thread directly into the alum. block.
Big job and tough to do without pulling the engine.
It may just be best to cut your losses and run ! sell it for scrap.
Those cars are not really that good.

JCarroll,

It's always a gamble when you install a used engine, but we have a big junk yard in the area that's run by a good-ol' boy named Bobby White.

If it were my car, I'd be calling Bobby. He does a really good job of sorting engines, transmissions, body parts, etc. when he hauls in wrecked cars. He'll install an engine and guarantee it for about 30 days or so.

If you have something like that in your area, you might give them a call.

Tom in TN

junkyard material. if its a used cad; they have zero resale. find something different; you'll be 1000% happier!!!!!!!!!

just sold a 98 with 70k on it for $3000 and was thankful as they usually don't sell that high!
this one was perfect; inside and out!

There are two versions one is 270 HP and the other is 300. The ninth digit tells which you have [VIN}. A new motor is about 3000 plus. They have come down a bit. If I was told my car was a 4-5 k repair I would start looking in the used Cadillac section of the paper.They don't have a real high resale with the price of gas. Used motors for these are too much of a gamble. [What does the mechanic mean by bad heads-valves not seating ,cracked ??-strange] At 105 thousand now get one at 80 thousand for about 2800 bucks.Once you get up around 120 thousand miles on these your getting close to exhaust rot out and more expense.

13 years old & 105,000 miles........I wouldn't dump $4-5K into that.

On a Northstar, it probably started with head gaskets leaking.

A brother-in-law of mine just went down the same road with an '02 and wound up trading for a Buick with GM's bullet proof 3.8. When my BIL bought that Cad, I could have warned him about it, but he would have just thought I was jealous because he was driving a Cadillac and I was driving an Olds.

the heads probably are not bad. did they pull the heads off and have them checked by a machine shop? I worked for cadillac dealer repairing that engine. the head gaskets do not go bad they pull the threads for the head bolts pull. the best repair is to stud the heads instead of inserts. the dealer possibly does not have any one there that they feel comfortable to do the proper repair thats why they are trying to sell them a motor.

I have a Northstar out of a 1993 with 30,000 miles on it in a crate in my home shop. I was going to try to find a 93 with a bad engine at one time. never happen anymore for me. I put the 30,000 on it myself.
I bought the car new and every now and then it would smoke like it was burning straight oil. Shut the engine off and restart it and no smoke. After about 30,000 miles of taking the car back in they put a new engine in the car. A week later the same thing with the new engine. After playing with it for a week they found the bracket that holds the PVC valve was bent down when the conditions were right it sucked oil. They bent the bracket back up so it looked like another Caddy they had opened up and it never happened again. Six months later the service manager said that cadillac had not called for the engine back and if I wanted it to bring in my pickup and get it.

What year Buick 3.8 those aren't exactly bullet proof either. GM did some redesigning of the intakes to create a water leaking problem.
And also on those years you got the window regulator problems too.

well lets see,what would a comparable caddy cost today?35-45 k?105,000 miles isnt didly squat these days .look on the net for a crate engine,probably could find one cheaper.

There are a lot of reasons a car can overheat that are way more likely than bad heads!

How confident are you in their diagnosis??


I bought a pickup a few months ago with 176,000 miles on it. The guy gave me a stack of receipts with it - including one for $450 for replacing the fuel pump in the tank.

I soon had trouble with the pickup - but knew it acted like it was the fuel pump. Was very surprised to get the tank down and find that it was OBVIOUSLY the original pump still in it - fixed the pump and no more problems. It has been a great pickup!

I felt bad for the guy I bought the pickup from. He thought it was a lemon because he kept pouring money into it. His biggest problem was trusting his mechanic...




Howard

The GM 3.8 Series II engine in my '96 pontiac had the intake manifold water leak. It was repaired by a dealer in '99. I've only changed: oil, filter, antifreeze (back to regular), radiator hoses, water pump and the serpentine belt on that engine since then. I'm very happy with it.

The dealer put a small white "campaign" sticker on the top of the radiator bracket to document the upgrade.

Test the temp sending unit for accuracy. Time for a new stat too.
If it's truly hot somebody may have been cheap and used tap water in the cooling system. And just enough ant-freze to colour the coolant.
Pull the rad and replace if at all scaled. Replace the hoses as the lower maybe collapsing. They will be rotten from age by now anyways.Replace the water pump as the impellers maybe corroded away.
What drives the fan on this vehicle, a viscous clutch?
I would try waterglass instead of replacing the engine. It it still leaks and heats. Scrap the clunk. It's 14 years old.
Has anybody pressure tested the cooling system?

Sounds like its not worth much.Buy a junkyard engine with low miles and replace it,if it really does have a bad head/headgasket.If it has been real hot it probably is the head gasket.

Tom lots of parts of the country just don,t have honest guys like White. They run a first class operation.

First off, what evidence did he give that "both" heads are bad? For that matter, what evidence is there that even one of the head gaskets is blown? And let's remember that the Northstar has a "limp home" mode, so just running out of water once probably isn't enough to wreck the engine.

This car needs a second opinion. Just because it's losing coolant doesn't mean it has a cylinder head problem. My sister was told that her Cadillac had a blown head gasket; it turns out it was just a leaky hose. So the first order of business is to take it to a competent mechanic (other than the dealer) who can hopefully determine if it has a blown head gasket.

Assuming the worst, that the head gasket is blown, then the next thing is to decide what to do with it. Your options are:

1. Try to seal the leak with one of the cooling system sealant products. The cost is cheap and you have little to lose. Google "northstar head gasket" and you find plenty of snake oil to choose from.

2. Do an in-vehicle head gasket replacement. I understand that this is something most shops won't attempt on the Northstar. Difficult to do with low probability of success.

3. Take it to a shop that specializes in Northstar head gasket repairs. It turns out that some folks have come up with head gasket replacement process that involves replacing the bolts with larger studs. Not cheap; the site below says it runs $2200. They have a list of shops that are licensed to do their fix. I have no experience with this particular repair or company, so I will not make any recommendation on their particular repair.

4. Replace the engine with one from a junkyard. Why would the junker engine be any better than yours?

5. Replace the engine with a new or rebuilt one (e.g Jasper). Is the car worth it.

6. Scrap the car.

If it was my car, and in good condition like you say, I'd opt for #3.
Northstar Perforrmance head gasket repair

everybodies guessin'
Have a '86 volvo that started missing at 200K so took it to a shop and the engine is bad. Asked him how he knew that. Well the compression is this on #1 this on #2 this on #3 and this on #4; nmbers 3 & 4 were low OK how do you know it's not valves he had shot oil in the cylinders and the compression didn't change. Then he offered the options:
1) He would put in a new engine for $4K
2) Donate it for $1.5K to 2K
3) Sell to him for a parts car, maybe 500.
Talked to the wife, we rebuilt it ourselves over ayears time and included updating other stuff on the car like springs, shocks, wheels and tires spent a total of $4K and it is her daily driver for the past 10 years.

My suggestion is ask the dealer how he knows the engine is bad. How does he know its bad heads.
Then decide based on the condition of the car if that's the only thing wrong. You decide to fix it Call Dick.

If you have ever worked on one of these newer engines with all of the sensors and crap it is a whole lot easier to go to a junkyard and get an engine with low miles and a guarantee and replace the whole thing than it is to get somebody to put in who knows how many hours worth of labor replacing a head gasket and then it not fixing the problem.Plus,in some cars it would be easier to replace the engine than to try and work on it in the vehicle.If you have to pull it out anyway,just replace it and go on.Probably save you 2000 dollars to replace it.You want to get an engine from a car that has everything on it so all you have to do is plug it in where it has plug ins,and replace as few accessories as possible.Cars are wrecked every day.That doesnt mean they are worn out junkers because they are at a junkyard.Of course some are,but you are buying a low mileage tested engine with a guarantee.Not going to Pick and Pull and taking it out of a ratted out ghetto sled they drug in and started stripping.Big junkyards have racks with engines on them and you can hear them run sometimes.If they put a guarantee on it they think its a good engine.Maybe you could get unlucky and get a bad one,but Ive heard horror stories from mechanics about rebuilt engines that were knocking as soon as they started the first time.Then the auto parts store didnt want to stand behind their guarantee.An engine thats had a blown headgasket has a good chance of having other problems like scored cylinders and weak rings after you put a new headgasket on.If you get lucky and it runs good and doesnt drink oil it will be a miracle.I spent years as a mechanic and rarely saw an engine that just needed a headgasket replaced and then it was alright.By the time its run to where it blows a headgasket it is probably either junk or close to it.Maybe if you caught it right when it got hot,and shut it off,and had it towed in and fixed you might be alright.If most people today were driving they would keep going until it quit going and its nothing but junk.

If he shot oil in the cylinder,and the compression DID NOT change,then it is a VALVE problem.If it was the rings it would go higher.

A 1998 doesn't have a book of 4-5 thousand,not even close.

It's bad because it's prolly a Northstar . known to puke headgaskets ,pain to work on .

Trucker, I'm sorry to hear your carriage return key broke again. I've got a spare keyboard I can send you if you like.

"you are buying a low mileage tested engine with a guarantee" Let's see, there's at least three fallacies in that brief sentence:

1) "low mileage" Where are these low mileage 1998 model year junkyard engines? Not very many 13 year old wrecks with less than 100K miles. Not the way people drive these days. If you're thinking of using a late model Northstar, those "sensors and crap" will give you a fit trying to make it work in the older vehicle. My BIL made the mistake of having a so-called mechanic put a junkyard engine in his car; although there was only a one year difference between the car and engine, differences in the engine electronics were enough that the "mechanic" couldn't figure out how to get it running after the swap.

2) "tested engine" You've got to be kidding me. Junkyards have engine dynos and the ability to run modern engines with all their electronics on a test stand? This isn't a matter of firing up a 350 chevy out of a '69 Impala, where you just need a little fuel and a battery to get it started.

3) "with a guarantee" Unless the junkyard will reimburse you the cost of installing a bad engine, their guarantee is worthless.

No matter what recommendation you give your step-daughter and her husband, if it ends up not working out, you'll get the blame.

I'd recommend you tell them... "Gee, I don't know what to tell you. You guys need to decide for yourselves." This is based on you saying "I know I'm only getting part of the story."

I don't have labor guide in front of me . Butas I recall you could be looking at $1500 - 2000 grand LABOR and misc parts to install a new or used engine . These things are not fun to work on .

I'd ask Dick how much he wants for that engine. I used to work for Cadillac, we made the the N*. It's a great engine, but it is a dual overhead cam, pretty complex. In fact the heads have more parts than the rest of the engine put together. And the Caddy's with all the options are hard to work on - we used to joke about the Cadillac leak test - open the hood, dump 5 gallons of water in, if any hits the floor, we have missing parts!! Again, it was a joke. I don't know where you are at, I know a mechanic here ( S. Michigan ) who used to train the dealer techs. I'd say the eproms in the engine control module might need updating?

But I'd look for simple, easy stuff first.

Good luck!

They are really not that bad to R&R but diffidently a different animal... I double the time guide and add a little... I beat the book on the first one I did and see no reason to back off the labor just cuzz i figgered out how to beat the book....

https://photos.yesterdaystractors.c...arameter=hobo,nc&mode=All&what=pieces

With the price of used vehicles dropping daily. Putting 5 grand into a 2-3 yr old vehicle would be something to consider.

4-5000 would be a great down payment on something else. or you could find a running northstar same year that is running for cheaper and have a parts car.

I would try some Blue Devil sealant. I think it works better and longer than the water glass products. If Blue Devil doesn"t work,then call them,get your money back and then junk the car.
blue devil

my 94 northstar caddy boiled out at 215k,,,wadded up trash / gmjunk, no wunder they went broke rumor has it over 40 %of the aluminum blocks were DOA rejects after being machined,

Well first off Im a mechanic not a geek.I dont even know what a carriage key is.I was in typing class for less than an hour and switched to art in high school.Dont regret it at all.Next is that big junkyards will have engines in a warehouse.They will have a story with them like this engine was in a car that had 80,000 miles on it and was running good and tested good compression when we pulled it.Just to see I even looked and for the same year as his car they have one for 1800 dollars.
I bought a car one time and drove it a short distance and it blew a headgasket.It was a dual overhead cam 4.6 in a Lincoln Mark VIII.I looked on the internet,found a big junkyard in Kansas City.They didnt have one that was what I was looking for,but on the internet they have where they can look at other yards for parts found a low mileage 4.6 out of Texas for 800 dollars.I got it for 880 dollars after they shipped it up here.Put it in and it ran excellently.I had a little trouble with it missing at first,but it turned out to be the big plug in where it plugs into the firewall had a bent pin in there.Otherwise everything worked and hooked right up.It was a 1993 and my car was a 1993.
Unless you cant find an exact year engine and you probably can,I wouldnt mess with trying to use a different year engine unless I put all of the accessories off of my engine on the newer one.That would add a few more hours to the labor at the least.Id be sure to ask mechanics their opinion of doing this before I tried to change years.If I had to,I would buy the whole front off of the car,frame,dash and all, if it was newer,and change computer and wiring harness and all rather than try and use a different year engine with the older computer.Try and make them a deal to bring them back the frame my old motor and wiring harness,computer,dash, once I got it running good.
Thats what I would do.You might be right and it might be hard to find one the exact year that old,but I bet you can.Also you would want to give a little more money for an exact year plug and play engine.Id say it would be worth 2000 for that car since they wanted 1600 for a engine with heads on it and nothing else.
Of course it would have to be up to who is spending the money if they would want to spend that much or not,and if you look hard you might beat that price too.I barely even looked and found that.Serious search might get the right year and all for a lot less.Maybe get the right year for a thousand.
Ive talked to a Ford mechanic who has worked on the 4.6 dual overhead cam engine,and he told me that it was by far the best way to go in my case by swapping the whole engine rather than put head gaskets in.Like you say its not a small block Chevy.Another thing to consider is also once you pull the engine out to replace the head gaskets,by the time you get it torn down,you could have the other engine in and running and be driving it.Those dual cam things are great when they are running,but a nightmare to work on.
I wouldnt mess with any junk yard that wouldnt guarantee the engine.You know if you talk to them a little they will usually either have the stuff,or find it like that one did for me.If its hard to find it will cost more.If its too much more junking the car might be the answer too.Plus a junkyard will probably have a way of hooking something to it to make it run.Or they might have it setting in the front of a car just for that purpose.If you want to hear it running.Also you can look on the internet for engines like that and it will say runs good,and probably have a picture of it,or it might not have a picture and it will say runs,high mileage and not in very good condition,low compression.They have all kinds,the better the engine the more money.
Ive bought more than one engine from a junkyard.Ill ask them before I buy it what they think of it,or which one is the best,and they will tell you.So far I havent got a bad one yet.I mean its not a perfect test to just start it up,but if they say yeah we had it running for an hour and didnt see anything wrong with it and it didnt smoke or anything,Id think like they do that its a good engine.If they tell you that one there just will run and smokes then you go on to another yard.Or you can ask if they can find a good one close.Most of those places have a network where they can look up stuff at other yards in the network.
Ive also noticed that they will have these engines setting in the rack,and even the tag on them will tell you some about it.So they dont go through the trouble of pulling it out and putting it in the warehouse unless they think its good.Thats the best I can tell you.Of course you have all different kinds of junkyards too.If you go someplace where you have to pull it out in the middle of a yard where cars are stacked 3 high all around you,then your chances might be quite a bit worse unless you can hear it run.Of course you will pay more for the ones they have in the warehouse,but you are expecting them to have a good one in the warehouse too.

Give it a compression test and put a vacuum gauge on it. Look for all the items which will cause overheating,eg. thermostat, radiator, partialy blocked exhaust etc.

(quoted from post at 01:24:45 08/10/11) I don't have labor guide in front of me . Butas I recall you could be looking at $1500 - 2000 grand LABOR and misc parts to install a new or used engine . These things are not fun to work on .

Click to expand...

Pix of a yota engine that fell out for a trans replacement,,, like the cat all the work was preformed while the assy set on the stand... A nice tool you can make for those that drop out the bottom... I have another one in the works with better wheels and a different adjustment system...

yep ,never give labor away because you worked smarter !

If it has been overheated too many times (more than twice in other words) I would NOT put a new engine in it.

If the engine has been hot, so has the transmission. It will be the next to go.

I would put it up for sale cheap, with a disclosure that it has overheating problems. DOUG