Engine/Transmission (1994 - 1998) A dead miss

[NScott]

I just bought a 96' Cab& Chassis 3500 with 5 spd. and 4:10 ratio.

It was sold "as is" and I knew it had motor trouble before hand. It was used as a service truck by a petrolem pump company and they said it had problems while on I-24 and they had to have it towed in. They took it to Southeast Diesel and had it checked out.

Southeast said that both push rods on #3 cylinder were bent, so they replaced them but the engine still had a dead miss on #3. They ran a compression check on #3 and found that it was down.

The engine seems to run ok other than a dead miss on one cylinder. The oil pressure is okay, there is no abnormal noises or grinding that I can here. There is no oil in the coolant or coolant in the oil. The only thing I know to do at this point, is to take the head off and see what everything looks like. I don't know what else it could be other than a bent valve. It seems to me that if it was piston trouble (cracked, come apart,etc. ) that you could here noises from the area. Would'nt it be raising *ell? Any other ideas??



P. S. They said the driver had a lead foot!!

 

[bmoeller]

Bent valve would be my guess.

 

[cartman]

i think you have a bent valve i guess the best thing to do remove the head and have a valve job done on it and you will be able to see what the cylinders look like let us know what you find

 

[NScott]

cartman, I'm scared to take it off... afraid of a cracked /busted piston!! I'll try to get to it either this weekend or next week.

 

[Dan_69GTX]

Do a leakdown check



To do this you install your fitting for the compression gauge and then apply pressure instead of read pressure. This will tell you where you have a leak (exhaust, intake, crankcase, etc)



try to have the cylinder at TDC for this.



Good luck!

Dan

 

[cartman]

hi scott i hear you just take the head off slow and sneak up on it how low was #3 hopefully there is no piston damage and you can just do a valve job on the head

good luck write back on what you find

 

[NScott]

Well, I finally got the head off today, just as I suspected, #3 piston is melted and galled. The pump was set at stock, stock turbo, stock everything... maybe a piston cooling nozzle stopped up. . what do you guys think? I have no idea why the #3 piston melted! It has scored the #3 cylinder walls somewhat. I haven't checked the head for warpage or cracks, but I would'nt be surprised if it wasn't also damaged. Now comes decision time. Which way do I go about repairing/replacing this engine?

Do I:

A. Take the block out, strip it, bore the one damaged cylinder and install the thin wall repair sleeve? I know this will involve stripping the engine completely and buying all new parts to "build " the engine. This way I will know what I've got when finished, but it will take longer and involve running around after various parts, etc.

B. Go for the quick fix. Buy a used complete engine out of a salvage yard? I have found some for around $2k complete from pump to turbo. Most need a new oil pan from damage in the various wrecks these trucks were involved in. I have found a 96' and a 97' currently that have around 100k miles. These prices were straight out- no core. Probably go ahead and pull the timing cover and tab the KDP before the install.

C. Go to Cummins and buy either as complete of a long block as possible to make the repair. Do they bore and sleeve their reman blocks and use standard size pistons? Or do they bore the block and just install oversize pistons?

D. Go to Cummins and just buy a reman short block to make the repair. Also same questions as in C above.



We will be using this truck as a work truck and it probably will not be bombed. If it is it will be only very slightly-- just for load pulling purposes only, if at all. The truck has a very good body, but it does have 213k miles (+-) and has always been used as a service truck.

Does anybody have the part numbers for any of the items in the repairs I have proposed? Namely:

1 The service cylinder repair sleeve?

2 The reman short block part #?

3 The reman long block part #?

4 Any other part #'s that you think I need to consider or

other parts that I may need?



All feedback appreciated on this decision I will be making.

 

[CATCRACKER]

i would gamble and get a used one for 2K and pop it in there. that way you can have a core and start building a race engine!

 

[bmoeller]

Sometimes you can find NEW 12v for about the cost of a drop-in reman. Just have to look around.