A Detroit 500 engine riddle, can it be solved

absolutely, if either the old turbo or new turbo was letting oil get through the intake side it definitely would run on oil and run as fast as it could till it found the weakest link! sorry to say but sounds like the shop he was having it repaired at didn't do their job.

 

With an oil runaway, the ignition switch, ecm disconnected, or anything will not stop the engine short of sealing off the intake air. That was one reason the 2 stroke Detroits had an emergency stop, which was a spring loaded flap that closed over the intake to prevent air from entering the engine.

The early Volkswagen diesel engines had a runaway problem/ Oil from the crankcase breather would accumulate in the intake, and when enough accumilated, the engine would run away. Theirs was fixed with a redesgned crankcase ventilation system. The VW engine was weak, but when they started running on engine oil you could hardly keep them slowed with all the brake you had. The engine oil acted like it tripeled the HP over straight diesel. The one I had would start rattling, smoke blue smoke, and take off flying. Really interesting when it decided to do this in town.

I guarantee that truck was running on engine oil. Make sure YOU are there to see the turbo taken off, and look in the intake pipe. Any fresh oil, and they owe you a new engine. If they take it off, the oil in the intake and the turbo might disappear.

 

absolutely stranger, take his advice, 1 of the 2 turbos failed.

 

Genius! Ya nailed it Stranger..

 

Oil seal on the turbo exhaust side, allowing oil into the hot exhaust pipe, which caught fire and went out the stack.

If they cleaned out the intake pipe, there should be no oil at all in it now unless the new turbo is bad. You will have to really look close if it is new oil, for it will be hard to see. Also check the intake where it enters the engine for oil.

It WAS NOT electrical.

 

The motor ran away because it had a fuel source, any time a turbo comes apart or is pushing oil, the charge air cooler needs checked for engine oil or debris before a new turbo is put on the engine. Sounds like the cac was full of engine oil but there is no way to know now. Im sure it was a sight to see when the motor went. I've heard of engines eating 10 inch thick phone books trying to get it to shut down.

 

yes, if the a2a was full of oil from the old turbo, then when the new turbo was put on and it wasn't cleaned then the new turbo just sucked the oil up out of it. I bet if they take the a2a off and turn it upside down, it will have oil running out of it.