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Matt, Engineer
Category: GM
Satisfied Customers: 21622
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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Engine blows oil out of crankcase vent stops if you

Customer Question

Engine blows oil out of crankcase vent stops if you disconnect pressure side of turbo but turbo show no signs of leaking on exhaust side or outlet side when crankcase vent disconnected from air inlet.
Submitted: 12 months ago.
Category: GM
Expert:  Matt replied 12 months ago.


can you tell me the make and model of the vehicle involved?

Customer: replied 12 months ago.
2004 international 4200 vt365 6 litre engine was dismantle piston checked bore checked new rings heads redone turbo checked does the same thing as it did when it was brought in. runs reasonably well
Customer: replied 12 months ago.
one comment was high pressure oil pump leaking into crankcase causing high crankcase pressure!
Expert:  Matt replied 12 months ago.


there should be a couple of breather paths on the engine

1 low pressure route for when the engine is off boost and a 2nd route for when its on boost

there should be a combination of pressure relief and 1 way valves to prevent boost pressure entering the crankcase

the boost pressure line will have a 1 way valve between the cam cover and inlet manifold to prevent flow in

so I'd say its likely that the 1 way valve is faulty or stuck

Customer: replied 12 months ago.
we will look down that path! I think its built into turbo assembly I will try to locate information for that !
Expert:  Matt replied 12 months ago.


I think that this engine manual may help

see page 17

Customer: replied 11 months ago.
The info you provided is the wrong. that's the new version updated engine. I sent you the year model etc. Navistar completely changed the engine due to law sued by Ford
Expert:  Matt replied 11 months ago.


ok this service manual should be the correct one

Expert:  Matt replied 11 months ago.


do you still need help?

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Customer: replied 11 months ago.
I am away in Austrailia my staff is still dealing with the problem most of info provided by you did not address original problem there dealing with a local machine shop rebuilder thanks