Hello all,

I've been having a problem with a nagging oil leak and what I think is excessive oil dripping from the road draft tube. I washed the engine and undercarriage and tried to locate the leak with the truck running at operating temp in my driveway, but no luck. No oil dripping from anything. This was done without driving it to warm it up. If I take the truck out for a drive and then look underneath, there is oil all over the bottom portion of the engine from the vacuum pump down. The area around the front crank seal is dry and I replaced the vacuum pump seal and o-ring. The engine only seems to leak when being driven and the turbo is providing boost. I've read on this forum about turbo oil seals going bad and pessurizing the crankcase and causing oil leaks. I found no oil on the intake side of the turbo but I do have oil coming from the turbo/exhaust manifold mating flanges. Also, there is some side to side and front to back movement of the impeller shaft. The turbo has about 210,000 miles on it and the engine itself has about 35k. I did not see any evidence of contact between the impeller blades and the housing. There is only light vapor from the road draft tube and no huffing. The engine does'nt smoke abnormally, has great power, starts fine and gets good fuel mileage.

I'm looking for opinions, comments, guidance or whatever before I start taking too many things apart.

Thanks, Randy

 

I would check the oil pan gaskets and bolts. As far as the oilfrom the turbo/exh flanges, If it is at the turbo out connection to the exh pipe you may have a turbo seal leaking, If it is at the exh man to head you have leaking valve stem seals or injectors dribbleing during cold operation, If it is leaking at the manifold to turbo it could be a combination of cyls leaking injectors or seals. Best way to start checking this is remove the flange on the exh pipe to turbo and check for oil in there. Then pull the exh man from the head and look in the ports for oil on the valve stems. If it is all wet and black you may have leaking injectors.

 

Try looking here: https://www.dieseltruckresource.com/...mpression+test
You might want to build one of these.
Tom