B6100 Engine rebuild impossible?

[wushaw]

It ain't all that bad to rebuild a little motor...tear it apart, take it all to a machine shop, get the machine shop work done and put her back together.

Sounds easy if you have done this before, if not then let someone else do it.

 

[ozzie tractor]

was this thing making some really bad rattles in the motor. i find it a bit hard to believe that a motor with very little or no oil pressure has not exploded in a shower of smashed metal. normally lack of oil pressure spins the big end bearings and the knocking which comes with a spun big end is fairly hard to miss. i agree with the above post. get a second opinion. have someone actually put a pressure gauge into the motor. it may not be the sender but another problem in the electrical system. it just seems odd to me for a motor to go this long with no oil pressure

 

[RobJ]

Did the shop stick a pressure gauge on the engine? Do you know what is the actual oil pressure? Most of the ground type sending units close the circuit about 5psi+/-. Low oil pressure usually means that clearances somewhere are high, but in most cases they are still getting oiled. A tight engine has higher oil pressure. I once had a CJ3B that would idle down to about 4psi, gas it and it'd spike up to 15. Never made a noise, probably still running. You could have engine wear all over the place, or one place real bad. Might even have a failed pressure relief valve spring.

In all my engine rebuilds I must say I never repalced a worn out oil pump, I replaced a lot of them but none had a total failure, they willusually put out plenty of oil and pressure.

On your tractor, if you rev the engine up does the light go off? I'd still want to see a pressure gauge on it when idling and revving. Personally I'd take the guys repair or see if he will take it back. Or just run it! Either way I'd put a mech oil gauge on there. You can also replace all the rod and crank bearings without removing the engine.

Good Luck,
Rob

 

[robbieo11]

i agree make them put a gauge on it

 

[sfixx]

Thanks for all the responses guys! I got the tractor back after the service and have had 2 days to run it. They replaced the oil pump and the pressure relief valve plus assorted seals, o-rings and gaskets. They did test the pressure before and noted 10 lbs at full throttle with zero at idle. After the service he told me it gained 2 lbs at full throttle but is still zero at idle. Before service the engine didn't make any really scarry noises but this is my first diesel and I figured the Mack truck sound is normal (firm knocking?). The biggest problem was that as the engine warmed up the low pressure warning light would illuminate at higher and higher rpms until after about an hour of work it would illuminate even at full throttle. Having a new or calibrated oil pressure sending unit would be good but you're right a true gauge would be best. I'll look into adding this asap. Now, I can work it hard and the the light doesn't come on, but after a full warm up if I idle back it gets to about 1/2 throttle before the light comes on. This is a much improved condition. The engine does smoke some, especially under a good load it will start to huff as it works up some "steam". Even at lower rpms it will sometimes send out little whispy smoke signals.

The previous owner is going to pay for this $700 service so I'm happy to let the matter go at that. I got the tractor for a bargain and will keep my eyes out for a parts tractor or spare motor. My local service shop was talking about better that $3,000 for an engine rebuild, which is more than the tractor is worth I believe. I don't have that much work for her and hope to nurse it along for a while.

Thanks again for commenting,

Steve