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Boost leak - compressor to oil passage

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Yo. Im sorting out a few boost leaks, and one of them is between the compressor housing and the turbos internal oil passages. With a tester attached to the turbo inlet and the rest of the intake piping capped off (disconnected from the engine), I can see oil being pushed through the turbo drain into the sump (I have a transparent hose, so can easily see this). This is a TD05HR.

Is this normal? Or do I have a problem?

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After some reading around, Im pretty convinced that the amount of leakage Im witnessing is normal, and in fact helps prevent oil leakage into the housings.

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Unless you're running something crazy high powered, your oil pressure should be quite significantly higher than your boost pressure anyway so there shouldn't be air leakage into the oil supply while running

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If its really bad it may have a worn oil control ring, if there is minimal oiling in the turbine and compressor housings you will be fine. 

As far as boost leaks go, a TD05hr should be cranking a few hundred cubic feet per minute when on song so any tiny air leakage would not even have a measurable affect. 

To put it in perspective I had a 6 inch long crack in the manifold on my car it still made 190kw at 8psi boost. The rest of the air was escaping out the hole in the manifold. 

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On 30/03/2019 at 15:49, Yowzer said:

Unless you're running something crazy high powered, your oil pressure should be quite significantly higher than your boost pressure anyway so there shouldn't be air leakage into the oil supply while running

Not the high pressure supply - the drain passages.

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Hey, dredging this up again.

Ive totally sealed the intake now, convinced theres no more problem there. The idle control valve blockoff plate needed sealing, and a few other minor leaks. This has raised my boost up to a max of about 6.5psi. Still getting bubbling through the turbo oil drain when static testing, but only sometimes, which is odd, and when it does, I hear air escaping through the PCV outlet, or when that is capped off, the dip stick tube. Perhaps a turbo tear down is in order...

Its either that, or the turbine not spinning up enough. Ive had issues with the internal wastegate not closing quite enough. I tightened the actuator rod up as much as I could, and that solved low boost issues last time. Ill try that again, but Im wondering if the exhaust housing is cracked and leaking pressure. Or possibly other pre-turbo exhaust leaks. All things to consider, I guess. Is cracking around the wastegate port common on TD05's?

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hey man, it is allways going to leak a bit of air into the oil when theres no oil pressure

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Yea thats what I figure too. Ill be searching for exhaust leaks for the time being. Pretty sure the turbo is A-ok.

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