3204 CAT engine question

Got a friend with a 943 CAT loader with a normally aspirated 3204 CAT engine in it. Long story short it's been acting underpowered, etc for awhile and someone told him the engine was worn out. I looked at it last night and found water and algie in the fuel system, etc, and that could very easily explain his problems. Unfortunately the other guy had already started working on it so it can't be run at the moment.

Now, my suggestion to him, given what I found, is to do a compression check and see if the engine is actually 'worn out', or wether the problem lies elsewhere, before doing anything else. His biggest problem is having 'cash on hand' to do anything if the engine that's sitting in it actually had to be rebuilt.

That being said IF he needs an engine he has found a fresh, rebuilt one that would fit in a 953 that he can do some trading on so he's have no cash outlay....which would make his situation alot easier.

The main difference between the two engines is the turbo and extra HP gained by it. The NA in his is 80 HP, and the turboed one is 110 HP. I've talked to several people that agree with me in saying the 943 and 953 are basically identical machines as far as the drive train, with the main difference being the turbo. Basically other than a bit more track length, the driveline (ie transmission, etc) is all the same, so the only difference is the turbo adding a few extra HP. In other words there's no reason he can't swap one engine directly for the other. The only rub any of us can see is that the cooling system may be a bit small given the 30 additional HP, but given the way CAT does things with their cooling systems being oversized, that probably woudn't be an issue either.

Now, to throw even more into the mix, someone else told him he could take the turbo off the one engine, change the injectors and fuel settings, and have a NA engine. That sounds plausible in one respect, but having built quite a few engines over the years, I know there is often a difference in the pistons/compression ratio on a turboed engine vs a NA engine. Thing is I have never messed with one of the 3204's to know, and can't find anyone around here that knows either.

So, my questions are---- Has anyone else done a swap like this and what did you do to make it work?--- Two---Has anyone worked on one of the 3204's to know wether the internals on a T engine are the same as on a NA one?

Any answers or insight would be greatly appreciated.

Hi Wayne, afraid I can"t answer your questions, outside my experience. I can offer that similar symptoms in my Cat 944 (different engine) was not low compression. It needed a governor rebuild mostly, and had a leaky fuel check valve.

Unlikely I ever would have gotten to the bottom of the problem without the aid of several Aussies on one of the Cat forums. All I know about Cats are what I had to learn to keep mine operational. A couple of local guys opined that I had a wornout engine, without ever checking that it was.

After the governor repair, Bertha (my 944) scampers up 40% slopes again. You know the importance of correct diagnosis. Pretty easy to find unqualified "mechanics".

Have them get it operational again clean the fuel system so you have good fuel pressure and see how it workes. Then we can help. The sooner those chancers get it back together and leave the better.
Later Bob

I am going to go outside my usual realm here and offer an opinion where I have NO knowledge of the question at hand.
If I were in a position to be replacing one of the 4 cyl. NA engines in one of my machines with a turbo'd one, I certainly wouldn't waste the time and money messing with it. I would install it and enjoy it!
But hopefully you have got the situation stopped short of that with your discovery of the fuel issue.
What is the other person doing to this engine anyhow? Where does one start when they're apparently only guessing?

Wayne, speaking of under powered, today I pulled up next to an old Ford L9000 tractor and trailer. He was up ahead of me slightly when the light turned green, so I caught up to and passed him in my company one ton. He was down at least one, maybe two cylinders. In all of my years, I have never ever heard a diesel running flat on one or more cylinders other than a jake brake. Never on a take off though. Maybe he had the jake on and didn't know it because he was unfamiliar with it. I imagined that he probably had a Cat 320x under his hood when I passed him. That was a strange sounding critter.

Mark

i forget where and when, but many moons ago i either heard or read that with diesels anyway, you don't really lose noticeable power from worn internals until its REALLY worn. in other words, wear is going to cause major trouble starting before you lose power.

generally when i start to lose power it is a heads up to change fuel filters.

i don't know anything about the machines you're working on, but why go through the trouble to remove a good turbo? if you don't want to stress the driveline and/or cooling system, just don't push it too hard. if the operator doesn't have the judgement for that, just turn down the fuel pump--in other words limit peak torque by cutting fuel delivery.

my $.02

I have no idea as to weather or not the loader will take the extra power. I would be a bit skeptical as to weather or not the 3204T is making 110 hp... I thought they were more often 90-100 hp... but I'm sure it could make that.
Simple solution in my mind... turn the 3204T down some. I'm not well versed in Cat pumps but I'd think it wouldn't be too difficult to limit the rack travel a bit more and solve the problem. Then he'd have a turbo engine that should be more efficient than the N/A engine without the worry of it overheating or tearing something else to hell.

Rod

The HP ratings came straight out of a CAT spec book so I know both are right.

Your pretty much on point with what I've been telling the guy. having talked to him and his son both it seems the power 'comes and goes' which tells me it's not a worn engine. The problem I'm looking at now is that when I talked to him this morning he said it was smoking really bad out the draft tube, which would indicate either a blown head gasket or alot of blowby past the rings. Guess I'll find out a more when I get a chance to actually work on it in the next couple of weeks.

Alot of the guys nowdays use the Jake as an alternative to double clutching. I've heard them going UP the haulroad in one of my customers quarries, hitting the Jake every time they shift a gear. Talk about something that sounds odd.......

Saddly this isn't the first time I've had this happen. Years ago I went behind a dealership mechanic who told a customer their engine was worn out. Turned out the fuel transfer pump was leaking into the injection pump, which had a stand alone oil sump, dilluting the oil and causing excessive wear on the internals. Got the injection pump rebuilt and the engine purred like a kitten....even though it wasn't a CAT...lol

The customer asked me to run the top end while I was there, so I took a longer look at things on the top end. Funny thing, none of the paint on the injector lines, the hold downs, or anything else was disturbed. In other words there was absolutely no way the other guy had checked anything before he went out on a limb with a wild a$$ed guess and said the engine was shot. Asked the customer how the guy had made his diagnosis but he didn't know. Showed him what I had found and he wasn't very happy with the fact that they would have happily charged him for a new engine in lieu of a simple injection pump rebuild.

That said, I see alot more things 'diagnosed' like that nowdays. I can only guess that the problem is that the modern 'technicians' have little to no diagnostic capability without their trusty laptop telling them which part to change.... Granted I'm no whiz with the new technology, but the old stuff isn't as hard as some think if you actually use your head and think things through.

After having gone through it, did they check the strainer and check valves in the transfer pump? From what I was told, the turbo 3204's in the 953 and D4H are squeezing every ounce of power out of the engine but at a cost. They are known to require more frequent rebuilds where as the non turbo versions aren't stressed to the limit and thus last much longer. 3204's only have 2 piston rings from the factory and apparently they have enough blow by when new it's hard to test on a used engine. IPD makes 3 ring pistons that are supposed to be much better and even increase compression.

From this point on, thankfully, I'm the only one that's going to be working on it. Hopefully once I get the fuel system cleaned out, etc I can get it to run again. My only problem now is the guy tells me this morning that he thinks it had alot of blowby (ie-puffing hard, and puffing smoke out of the draft tube), then he also tells me that it had started to run a little hot at times also.

All of this has got me thinking now that he might have a blown head gasket, along with the contaminated fuel, cauising the symptoms that have been described thus far.

I hate coming in behind someone else and trying to diagnose a problem they have already 'diagnosed', especially when I have never seen the engine run and exhibit any of the symptoms described. The last time I ran it was nearly 6 years ago and it ran just fine then. The thing with the economy like it is/was, it didn't run that much between then and the time it was 'diagnosed' to be worn out.... Guess I'll find out what's going on in the next week or so when I actually get the opportunity to work on it.

Based on what I saw the other guys hadn't checked anything, or done anything but started a teardown based on a wild guess. Heck the water and algie I found was in the fuel strainer. It was nearly 3/4 full of water with a generous amount of algie/slime present as well. The guys son told me they had already cleaned it out once before when it got stopped up and put an algecide in to kill the algie, but, apparently, it hadn't worked very well, based on what I saw.

Thanks for the info on the pistons/rings. Do you know if the turboed engine has exactly the same pistons and makes the same compression as the NA does? I know on many engines the compression is a bit lower for a turboed engine vs a NA engine. Do you have any info on that spec?

There's so many variations on the 3204 that I think the only safe way to know what it is or what it's specs are is get the arrangement number and go from there.
I would expect the 3204T to be no different than any other turbo engine... heavier pistons, nitrided crank, lower compression ratio, different valves, etc.
Personally I don't think the 3204T is in any way stretched in the power it's making. Mine is running at 90... but even at 110 it's not a high ratio per cubic inch compared to just about any engine out there. The old 4 cylinder Allis engine made as much power on 200 inches. The 3204 is 318 inches.

I do know from looking at a couple of them recently tho... the 3204 as used in the old excavators is a vastly different looking engine than what's used in my D4H... but the dozer is a Mitsu build, not Peoria.... it may conform to basic 3200 series specs and use a Cat fuel pump but that's about where the similarities end.

Again... I'd just derate the pump on the new engine and not worry about it.

Rod