Good old smoking thread!

jetpilot · May 11, 2009, 05:53:05 PM

Hi guys. Recently changed my turbo, many reasons for this but one was down to smoking at idle, there was some history with the turbo and when checked it was found to be not in very good condition.

It was replaced with a nice almost new T04z, made sure to get a 1mm restrictor in the oil feed line but still getting some smoking on idle, but not under load and not as apparent as before.

When the turbo was off, downpipe and manifold were checked and all looked dry, no wet oil, but comments were made by turbo company and garages that it did look like it had been running very rich.

So, what are peoples thought on possible causes, could it be engine or more precise oil ring failure or something a little less costly like mapping?

pdtaylor18 · May 11, 2009, 06:55:24 PM

When does it also smoke,just after a short burst and when you come off the gas? or only at idle?
I did have a very similar problem on my turbo (TII FC) and after replacing the turbo with a good 2nd hand one it ended up being the Oil control rings and hence subsequent rebuild. I had no signs of oil in the exhaust and none in the compressor housing. This is not to say this is whats wrong with yours but its probable.

Anyway you need to do the basics first such as making sure the oil return pipe is not higher than the turbo and unrestricted ie no kinks or sharp bends etc
make sure the engine is breathing correctly, intake nice and clear and that there is no oil in the compressor inlet. If there is oil there then it might be breathing heavily and dumping it straight into your intake system. If you have a catch tank then its not that if its routed to that. If you have no catch tank then just let this hose be open to atmosphere,also take of your oil cap and run it with it off and see if it makes a difference.

jetpilot · May 11, 2009, 08:50:02 PM

It would seem only at idle, under load it seems fine. Will check the points you raise as they all would make sense.

Thanks for pointing me in the right direction.

pdtaylor18 · May 11, 2009, 08:55:31 PM

One thing I did forget to mention is the OMP,is yours still connected or do you run pre-mix? It has been known for these to play up and should not be over-looked.

Grizzly · May 11, 2009, 10:40:36 PM

Try blanking off the breather (oil filler to inlet) i have heard they can give this symptom.

jetpilot · May 12, 2009, 02:25:27 PM

Thanks guys. The curious thing is, its definately not as apparent with this new turbo. Ill try the above mentioned and see if that helps, i know for sure my oil drain doesnt look to handy.

jetpilot · May 12, 2009, 02:26:52 PM

No still running the omp, was one of my thoughts, but with a restrictor in place shouldnt this stop this?

jetpilot · May 12, 2009, 04:02:46 PM

Quote from: Grizzly;606923Try blanking off the breather (oil filler to inlet) i have heard they can give this symptom.

Just to confirm you are talking about the pipe running to under the plenum?