How to check turbo oil seals? - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Simonh · 30th August 2006, 09:02 AM

Before I stripped my engine down I was getting a little blue smoke and oil usage. I had thought this might be due to the turbo oils seals being past there best, but with the engine apart it seems oily on the inside - which would be pre-turbo.

so now I am thinking that the turbo may be fine, but I don't want to put it back on and have to take it off again because it has a problem as well.

is there anyway I can check it or is it a case of sending it away for checking?

many thanks

Simon

TokyoJoe · 3rd September 2006, 10:23 AM

How were the elbows and front pipes? Oil buildup?

Simonh · 3rd September 2006, 11:30 AM

the intercooler pipes were not particularly oily......

Warpspeed · 4th September 2006, 12:46 AM

With a correctly installed turbo, oil should never really leak out of the turbo because the pressure inside the turbo bearing housing should always be the same or lower than the pressure behind compressor and turbine wheels.

An oily turbo is invariably due to internal pressure buildup, which usually means something wrong with the oil drain and vent return to the sump. Or it may be severe piston ring blowby pressurising the whole sump (and turbo).

A tired engine can not only have severe blowby, it can dump all the oil fumes via the PCV into the induction system, making it look like the turbo compressor seal is leaky.

Another cause of severe oil leakage with ball bearing turbos can be excessive oil volume into the turbo. There absolutely must be an oil restriction orifice in the oil line to the turbo.

I would just clean up the turbo and replace it onto your freshly rebuilt engine. Chances are pretty good that there will be absolutely nothing wrong with it.

Simonh · 4th September 2006, 08:13 AM

the turbo isn't oily at all, but the engne was using a little oil and there was some blue smoke on revs.

I'm going to put the turbo back on - it's on a high mount manifold so it is easy enough to change it if I need to later.

thanks

Simon

30th August 2006, 09:02 AM	#1 (permalink)
Simonh GTROC Member Join Date: May 2002 Location: Nottingham Posts: 3,023	How to check turbo oil seals? Before I stripped my engine down I was getting a little blue smoke and oil usage. I had thought this might be due to the turbo oils seals being past there best, but with the engine apart it seems oily on the inside - which would be pre-turbo. so now I am thinking that the turbo may be fine, but I don't want to put it back on and have to take it off again because it has a problem as well. is there anyway I can check it or is it a case of sending it away for checking? many thanks Simon __________________ Composite Design Studio webpage Doing it is not enough - it has to be done right. My Auto Journal

3rd September 2006, 11:30 AM	#3 (permalink)
Simonh GTROC Member Join Date: May 2002 Location: Nottingham Posts: 3,023	the intercooler pipes were not particularly oily...... __________________ Composite Design Studio webpage Doing it is not enough - it has to be done right. My Auto Journal

4th September 2006, 08:13 AM	#5 (permalink)
Simonh GTROC Member Join Date: May 2002 Location: Nottingham Posts: 3,023	the turbo isn't oily at all, but the engne was using a little oil and there was some blue smoke on revs. I'm going to put the turbo back on - it's on a high mount manifold so it is easy enough to change it if I need to later. thanks Simon __________________ Composite Design Studio webpage Doing it is not enough - it has to be done right. My Auto Journal

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread:

3rd September 2006, 10:23 AM	#2 (permalink)
TokyoJoe GTR Register Member Join Date: Aug 2006 Location: YOKO-YOKO Posts: 130	How were the elbows and front pipes? Oil buildup?

4th September 2006, 12:46 AM	#4 (permalink)
Warpspeed GTR Register Member Join Date: Apr 2003 Location: Melbourne Australia Posts: 169	With a correctly installed turbo, oil should never really leak out of the turbo because the pressure inside the turbo bearing housing should always be the same or lower than the pressure behind compressor and turbine wheels. An oily turbo is invariably due to internal pressure buildup, which usually means something wrong with the oil drain and vent return to the sump. Or it may be severe piston ring blowby pressurising the whole sump (and turbo). A tired engine can not only have severe blowby, it can dump all the oil fumes via the PCV into the induction system, making it look like the turbo compressor seal is leaky. Another cause of severe oil leakage with ball bearing turbos can be excessive oil volume into the turbo. There absolutely must be an oil restriction orifice in the oil line to the turbo. I would just clean up the turbo and replace it onto your freshly rebuilt engine. Chances are pretty good that there will be absolutely nothing wrong with it.