rebuilt diesel engine blew up

[bandit86]

Bought a 1970 unimog 406 yesterday, with a MB OM352 inline 6 diesel engine, fresh rebuild.

I picked it up, we did an oil change on it right at the guys shop, there was too much oil in the block, we didn't want to blow a seal. left for drive home. everything was fine untill 4 hours or 200 miles later when the engine started knocking.

pulled over, oil is 3 inches up the dipstick reeking of diesel fuel. oil covering the entire front of the engine bay, looks like it blew out some somewhere near the top.

Anyways, it's my first diesel and I'm not familiar with it, the injection lines go through the side of the head and the injectors are under the valve cover. I'm guessing one of those lines loosened off, pumped the block full of diesel, thinned it out till there wasn't enough viscosity left to keep it running. Question is- If that is what happened with the injector lines, should the rebuild shop be responsible or the guy that swapped engines?

I literally got to within 2 blocks of my house. I'm not blaming the guy I bought it from, he sold it to a guy who didn't finish paying for it but ran it out of oil, paid for a rebuild then worked out a deal for money owing, so my guy ended up with the truck back with a new rebuild that he never drove.

 

[Bondo]

Re: rebuilt diesel rngine blew up

Re: rebuilt diesel rngine blew up

Ayuh,... It's alittle early to be playing the Blame Game ain't it,..??
1st step is to tear it down,+ SEE what went wrong...
Then if you want, you can play the Blame Game in a court of law...
Unfortunately,...
Sometimes in a garage, or a court of law, it comes down to $h!t Happens....

 

[bandit86]

Re: rebuilt diesel rngine blew up

Re: rebuilt diesel rngine blew up

I never worked on diesel engines, I just wanted to know if injector connections under the valvecover are done by the rebuild place or the mechanicn that pulled or connected engines. From the sound of my guy it was an inhouse job anyways.

 

[JustJason]

Re: rebuilt diesel rngine blew up

Re: rebuilt diesel rngine blew up

sounds more like somebody didn't know how to use a dial bore gauge, didn't know how to check for piston to cylinder wall clearence, didn't know how to fit a piston, didn't know how to check ring end gap, or just plain old for got to put 1 one or more rings.
Unfortunately all you can do is call the seller, drag the motor back to him, and do a dismantle together if he's not willing to give you your money back.

 

[DECK SWABBER 58]

Re: rebuilt diesel engine blew up

I'm guessing one of those lines loosened off, pumped the block full of diesel, thinned it out till there wasn't enough viscosity left to keep it running.

Guessing or assuming is never a good idea.

Whoever is at fault, if they are reputable, will stand behind their work.

 

[bandit86]

Re: rebuilt diesel engine blew up

I was right, #2 injecotr had a very loose line. pumped the sump full of diesel, thinned out the oil and spun a bearing. Why didnt I see the oil pressure drop you ask? Well, seems someone tied the water temp wire to the oil pressure sending unit, showed full pressure once it started

 

[DJ]

Re: rebuilt diesel engine blew up

I was right, #2 injecotr had a very loose line. pumped the sump full of diesel, thinned out the oil and spun a bearing. Why didnt I see the oil pressure drop you ask? Well, seems someone tied the water temp wire to the oil pressure sending unit, showed full pressure once it started

You wouldn't have. Oil pressure guages measure pressure-not viscosity. A good oil pump would make up the difference.

Your FIRST CLUE (ignored) would have been the overfilled crankacase to begin with.

 

[cheburashka]

Re: rebuilt diesel engine blew up

You wouldn't have. Oil pressure guages measure pressure-not viscosity. A good oil pump would make up the difference.

Your FIRST CLUE (ignored) would have been the overfilled crankacase to begin with.

Second clue would have been the fact that it read full oil pressure before the engine even started.

 

[DJ]

Re: rebuilt diesel engine blew up

Second clue would have been the fact that it read full oil pressure before the engine even started.

Yup.

 

[bandit86]

Re: rebuilt diesel engine blew up

You wouldn't have. Oil pressure guages measure pressure-not viscosity. A good oil pump would make up the difference.

it would make up the difference, untill the oil is so thin it'll leak out of the bearings faster then the pump can pump

I tried it before I took the instrument cluster apart, the temp gauge feed kept the oil gauge signal high. The gauges have 12V on the signal wire, and a thermistor in the temp sender grounds it out for a hot signal. the Oil pressure goes to low resistance for low pressure, but the low pressure resistance was too high to allow both 12V signals to go to ground.

 

[kenmyfam]

Re: rebuilt diesel engine blew up

Second clue would have been the fact that it read full oil pressure before the engine even started.

That should raise a red flag !!!