Chronic turbo leak - I have tried it all I think
#17
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https://rennlist.com/forums/993-turb...t-turbo-2.html
I checked that thread you posted a while back
Did the test Kevin suggests in that thread.
Almost no oil coming out, less than what Kevin indicates there so not a filter issue.
How did you end up solving your smallish leak/puff of smoke at start up ?
Thanks a lot !
I checked that thread you posted a while back
Did the test Kevin suggests in that thread.
Almost no oil coming out, less than what Kevin indicates there so not a filter issue.
How did you end up solving your smallish leak/puff of smoke at start up ?
Thanks a lot !
#19
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What's your oil pressure like - could the relief valve be jammed?
Did the leaking start after the rebuild? Can you ensure the turbo vent lines are routed to the right place and are not seeing boost pressure but rather seeing crankcase pressure?
And what's the oil level on the dipstick when the engine is hot?
Did the leaking start after the rebuild? Can you ensure the turbo vent lines are routed to the right place and are not seeing boost pressure but rather seeing crankcase pressure?
And what's the oil level on the dipstick when the engine is hot?
#20
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What's your oil pressure like - could the relief valve be jammed?
Did the leaking start after the rebuild? Can you ensure the turbo vent lines are routed to the right place and are not seeing boost pressure but rather seeing crankcase pressure?
And what's the oil level on the dipstick when the engine is hot?
Did the leaking start after the rebuild? Can you ensure the turbo vent lines are routed to the right place and are not seeing boost pressure but rather seeing crankcase pressure?
And what's the oil level on the dipstick when the engine is hot?
Note that the turbos leak on idle. There I have between 1,5 and 2 bar when the oil is warmed up.
Oil level is at MIN on the stick
Vent lines checked and rechecked ! Also the test with breather lines unplugged, engine running, no oil coming out of the vent holes but turbos steal leaking point to "something else" I guess.
The oil leak started after a hot day at the track, check the picture. That track has a lot of long straight lines. At the time I had a relatively restrictive exhaust to pass the 95decibel checks and it got really warm back there. The car was really moving though... but the day after drip drip drip
#21
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The lubrication diagram I have for the 993tt (from Volume 1 of the factory shop manual) says the pressure relief valve opens at 5.3 bar and the safety valve at 9 bar. Could this be the cause?
#22
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Thx for the technical details though
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And sure worth another check.
#23
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I don't confess to know the intricacies of the turbo's oil seals but if the oil pressure is too high isn't it possible that the seals have been damaged and will leak at lower pressures? Does FVD do something special to their turbos in that area making them more susceptible to damage from too high oil pressure while stock K16s (as on the other car and the ones you borrowed) cope fine? A fair bit of speculation on my part but as you seem to be at a dead end I thought I would throw all this out there.
"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" - Sir Arthur Conan Doyle
"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" - Sir Arthur Conan Doyle
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#24
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I don't confess to know the intricacies of the turbo's oil seals but if the oil pressure is too high isn't it possible that the seals have been damaged and will leak at lower pressures? Does FVD do something special to their turbos in that area making them more susceptible to damage from too high oil pressure while stock K16s (as on the other car and the ones you borrowed) cope fine? A fair bit of speculation on my part but as you seem to be at a dead end I thought I would throw all this out there.
"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" - Sir Arthur Conan Doyle
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" - Sir Arthur Conan Doyle
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Thanks a lot it's appreciated
#26
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For the record - Answer from Porsche AG is that the high oil pressure is normal as the pressure relief valve cannot keep up when Revs go up quickly.
For what it's worth.
They were not that helpful otherwise.
For what it's worth.
They were not that helpful otherwise.
#27
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It is interesting that there are two relief valves - seems to imply that it's known that the first one can't always do its job.
I can just about accept that if the revs are rising fast the valve may not be able to respond quickly enough but it looks like a simple spring-operated valve with no dampening so I'm a little puzzled. And at steady revs you should never see more than 5.3 bar oil pressure or the first valve is clearly not doing its thing.
When was the last leakdown test done? If you remove the dipstick is there any pressure in the crankcase?
I can just about accept that if the revs are rising fast the valve may not be able to respond quickly enough but it looks like a simple spring-operated valve with no dampening so I'm a little puzzled. And at steady revs you should never see more than 5.3 bar oil pressure or the first valve is clearly not doing its thing.
When was the last leakdown test done? If you remove the dipstick is there any pressure in the crankcase?
#28
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It is interesting that there are two relief valves - seems to imply that it's known that the first one can't always do its job.
I can just about accept that if the revs are rising fast the valve may not be able to respond quickly enough but it looks like a simple spring-operated valve with no dampening so I'm a little puzzled. And at steady revs you should never see more than 5.3 bar oil pressure or the first valve is clearly not doing its thing.
When was the last leakdown test done? If you remove the dipstick is there any pressure in the crankcase?
I can just about accept that if the revs are rising fast the valve may not be able to respond quickly enough but it looks like a simple spring-operated valve with no dampening so I'm a little puzzled. And at steady revs you should never see more than 5.3 bar oil pressure or the first valve is clearly not doing its thing.
When was the last leakdown test done? If you remove the dipstick is there any pressure in the crankcase?
Previous one was in the winter of 2015. Good results as well.
Done at 2 different places.
No pressure in the crank case that I can feel. No vaccuum or no force that would push the dipstick out.
I will check with my mechanic if the high oil pressure was a peak pressure or steady.
Both my mechanic and Kevin lean towards the turbos. Searching Rennlist Kevin has indicated that brand new KKKs or rebuilt KKKs 16s or 24s can leak from day 1 :-(
#29
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https://rennlist.com/forums/993-turb...t-turbo-2.html
I checked that thread you posted a while back
Did the test Kevin suggests in that thread.
Almost no oil coming out, less than what Kevin indicates there so not a filter issue.
How did you end up solving your smallish leak/puff of smoke at start up ?
Thanks a lot !
I checked that thread you posted a while back
Did the test Kevin suggests in that thread.
Almost no oil coming out, less than what Kevin indicates there so not a filter issue.
How did you end up solving your smallish leak/puff of smoke at start up ?
Thanks a lot !
I already had the check valves on the Turbos
Done
RUF Germany may be able to help you.
#30