Engine/Transmission (1994 - 1998) 400k miles too much??

[78cummins-wagon]

is 400k to much on my 1994 2500 auto trans. 4x4, with 3. 54 gears to try to put some power through it? i know its getting kinda high, but i've also herd that the cumins can run over 1,000,000. if its not to many miles, what should i do to it performance wise? any ideas would help. thanks

 

[Vaughn MacKenzie]

Depends on the current health of the engine. . . unless it was taken care of it could be getting a bit tired, but these Cummins engines still perform great even if they're past their prime. There are guys on this and other boards with more than 400K handling upgrades just fine.

My '96 was stock when I bought it at 351k, I've done some mods (injectors, plate, 3K GSK, larger turbo) and it's had some minor issues. . . it has more blowby and uses more oil than newer engines, and has a slight miss at idle, but other than that you'd never have any idea it has the 410,000 on the clock.

 

[Joseph Donnelly]

The ring seal is not as good as new, and blowby will tell you whether it is very bad yet. By now you should definitely do a valve job and be sure the valve guides are within specifications at that time. You won't know how much power you have lost through a worn out valve job, etc. unless you dyno test the truck. Yes, they will go far more miles than that, but performance is lower than when the engine was new. You can add power and that may or may not accelerate the wear. Higher exhaust gas temperatures from using more power, and more turbo wear from fast boost changes and more boost pressures can both increase the rate of failures.

 

[Vaughn MacKenzie]

Joe is right, a valve job wouldn't be a bad idea. I did the valves on my '96 once, the guides & valve stems were in great shape but the valve faces & seats were definitely pitted & showing wear. But. . . I wouldn't pull the head just for doing a valve job, wait until you need to for something else such as porting, replacing the head gasket, etc.

 

[CumminsPower98]

I have very near 400k on mine and it's still going strong. I did a head gasket (due to accidental over boost) at 247k and had a valve job done then. Running 15w40 Amsoil my consumption has been averaging 1 qt/3000 miles. This is running OTR with about 45% towing. I have yet to see what it does putting around town again since I stopped driving. Used to be 1 qt/6000 miles but that was at a much lower mileage.

 

[Vaughn MacKenzie]

Just read about a guy on dieseltruckresource.com who pulled the head on his '97 3500 for the first time, at 1,391,000 miles . . . hopefully he's planning a valve job

 

[78cummins-wagon]

thats amazing! i got my truck for $1200. its got little problems but for the price i couldnt pass it up. i love it and everything works, or did work untill od went out. well monday will tell me how much is owed to be able to go 100mph again

 

[Joseph Donnelly]

78, you need to do the KDP fix and replace the exhaust manifold with a 3-piece (it is a very same assumption yours has shrunk so much it is bending the bolts).

 

[MountainMan1]

I am at over 410K and haven't done anything major except for mods. I burn about 1/4 qt of oil every change at 10K. I run rhis truck hard alot and when I am hauling, which I do professionally, I am putting about an extra 100 hp to the wheels over stock with an slight upgrade of torque. So far my main concerns have been the driveline, but now I am listening to the engine very closely!



The first few miles and the first 70K miles I was very careful how I treated the truck, particularly the engine, I don't mean I never got into the throttle but I treated her like a nice women!



I think breakin is the key to longivity, however yours is used and you'll just have to believe it was treated right.



With the deal you got you can't go wrong in any case... . good luck and enjoy!



Peter

 

[CumminsPower98]

its interesting the big differences in oil consumption I see around these forums. For example mine uses a lot more than the previous poster. I did buy mine with 67k on it so I have no clue how it was treated. I know some probably has to do with the quality of the parts and assembly also.

 

[Fordiesel69]

Mine burns / leaks 1qt every 3k miles and it has 254k on it. Blowby is seen at the breather tube but it does not look excessive.



I would say go for your upgrades, whats the worst that could happen? Just get the KDP fixed.