Engine/Transmission (1994 - 1998) Turbo bowing out tappit gasket??

[Tyler1]

Ive got a aftermarket turbo on plus all the other hop ups... ... ...



were driving cross country and have starting blowing out all our oil, looks like out the tappet gasket not the blow by tube,



rings were just tested a few months ago and were fine.



cummins mechanic seas the turbo has to much play and is pressurising the crank case.



but we have been to 3 cummins garages so far as we travel and each garage gives a different answer... ... ... ... ... ... ...



were are losing about a gallon and a half an hour at 70mph, if we stay at 55 we only lose about a quart and a half, were guessing this is cuz we are keeping the boost down



need help pls send suggestions we are hold up in Lexington Kentucky trying to fix this so we can get to New Orleans

 

[Bob V]

I dont think that it is the turbo. Make sure the draft tube is not restricted. If the starter was recently removed the tube can easly get pinched off when reinstalled

 

[Tyler1]

draft tube is ok

 

[Tyler1]

acually tube is gone it was all drie rot and the mechanic took it off

 

[Redram 1]

re

Put the gasket back on,then stop at a auto part store and buy one of those pop in breathers and put it on where the oil fill cap goes.

 

[Tyler1]

how much pressure is normal in the crank?? at idle when i take the oil fill cap off you can feel the pressure coming out, how do I tell if its a normal amount or not??

 

[Tyler1]

allso we just found two of the valve cover cap gaskets wer pichned so wer replacing them, do you think that they would lose allot of oil?? at highway speeds?

 

[CumminsPower98]

Vacuum leaks can also cause this as the pump vents into the gear case.

 

[Tyler1]

hmmmmmm how could i check for vacuum leaks??



how much play is ok in the turbo shaft???

 

[Vaughn MacKenzie]

I would suspect the turbo like one Cummins mechanic suggested. A vacuum pump venting a lot of air into the crankcase probably isn't going to generate enough pressure to blow out the tappet cover gasket, or cause as much oil consumption as you're seeing. A defective turbo bearing seal could definitely cause a problem like this since boost pressure can blow a large volume of air into the crankcase and pressurize it.

Vaughn

 

[CumminsPower98]

Agreed, I forgot about the gasket leaking. However I did see a post not long ago where the truck ended up having a bad vacuum leak and it was blowing a lot of oil out at high speeds but I don't remember how much.

I would suspect the turbo like one Cummins mechanic suggested. A vacuum pump venting a lot of air into the crankcase probably isn't going to generate enough pressure to blow out the tappet cover gasket, or cause as much oil consumption as you're seeing. A defective turbo bearing seal could definitely cause a problem like this since boost pressure can blow a large volume of air into the crankcase and pressurize it.



Vaughn