NH L781 Deutz wet oil out the stack slobber

[taggmann]

Couple years ago i bought a L781 w/rod through block 3-cyl air cooled Deutz. Picked up a used one from a dismantler/rebuilder. Had pick of several. Used from a fleet of air compressors. So when faced with multiple choices of palletized used engines with ? hr.s cant hear run and all look to be the same. I went through them all and checked; oil, dirt in cooling fins ( figured if dirty probly ran hot), borrowed a wrench and gave each one a complete turn also trying to check for excessive free-play and exhaust manifold for oil or anything out of ordinary. The one i picked had no oil in the exhaust manifold. I changed over flywheel, oilpan ect.. filled it with Rotella 15-40 from sam's and now it slobbers oil from the exhaust. its dripping all over the place. runs good otherwise plenty of power, not missing, seems worse after idle. originally seemed like just one cyl doing it. I guess it could be just wore-out but it starts good and runs clean at first until oil show starts. it also will run on the oil intermittently, the diesel rattle will increase, rev up slightly and blow a large quantity of smoke. Any ideas ? Thanks.

 

[willie59]

Is this the 913 air cooled engine, not the oil cooled Duetz that has a fan blowing air through an oil cooler. It it's the 913 air cooled, pluck your exhaust manifold off and see which cylinder is slobbering. Once you've found it, take that cylinder jug apart and check it out. You could just have a broken oil ring. If the jug and piston is still good, you might just need some rings. A leaky injector can cause what looks like oil slobber, but you mentioned it fired right off with smoke clearing quickly, and runs darn good. Doesn't really sound like a bad injector.

 

[taggmann]

Thanks for the reply atcoequip. This is the motor with air shroud and finned jugs. the oil cooler is a length of fin-tube in the air shroud. Yeah I would doubt it is a bad injector due o the quantity of wet oil making it out the exhaust pipe. Makes a lot of sense it could be a oil ring, maybe the thing sat sideways on a pallet for a long time and stuck a ring? How about the valve seals or any other way to introduce oil into the cyl.?

 

[willie59]

Yep, sounds like a 913. Good engines. I don't thing a valve guide seal would slobber oil, might have oil burning smoke, but not slobber. It could be a head gasket. I haven't been into one of these engines for years, can't remember how the oil gets to the valves of each jug. If it were me, I'd ID the leaking cyl and dig into it, curiosity kills me!

 

[taggmann]

yep suppose its time to dig in! not Sure when but I'll let you know what I find. Thanks!

 

[bobin35]

Under the valve cover there is a plug to access the head bolts down by where the manifold fastens to the head make sure those plus are tight i think it takes an allen wrench.

 

[taggmann]

Hi bobin35, Thanks for the heads up, so up to speak.

 

[taggmann]

Well got to that deutz today. The plug for the headbolt on the exhaust side was unscrewed, sitting in place. It rattled around enough to mess up the threads on the alum head and the brass plug. I filed the treads off the old plug in 3 places and used it as a makeshift tap. Got new (used) plug from the blown parts engine, used paint for lock-tite (Sunday so the local napa store is closed) and crammed the plug in, went in stiff, hope it holds or guess I will have to change the head. Thanks, Taggmann