Does this make any sense. I get smoke on start up that I am pretty sure is not coolant. I know this can come from several sources. But every once in a while it doesn't happen at all. I am wondering if it is the seals on the rotors that leak when they are in a certain position on the shaft, but won't leak at other times when the rotors are high, or the system drains somehow. The times when it doesn't smoke is very seldom but it is very noticeable that the exhaust is clear and not the usual smoking on start up. All other variables I can think of are controled for this observation, several days between start up, oil condition, position of the moon, etc.

Can anyone else think of a reason why smoking on start up wouldn't occur sometime?---- Which may help me diagnose why this happens.

 

How many miles on you FD?
How old is the core on the car ?
Has the core been ported ?
What type of turbo or stock turbos and are they new ?
What PSI are you running at ?
Do you have the stock Intercooler ?
Do you have any oil residue in you intake pipes?
How much oil are you burning between oil changes ?


Well answer a few and some people might answer your thread.

Read this: http://www.rotaryengineillustrated.com/re101.php

and find this guy to work on your car.

 

Thanks for the link, it looks interesting.

My car is stock with about 80K on the engine-only mod is a downpipe. I suspect the oil rings are worn. It doesn't burn much oil but of course I see fuel dilution so it is hard to tell. It has alot of power and passes emissions fine.

I just think it is curious that one out of 20 times it starts up with no smoke. I don't know the details of the internals of the engine well enough to tell if leakage across the seals would occur more often sometimes than others or if other things could cause this effect.

Just an obseration.

 

More than likely its your turbos. I had the same thing before my rebuild and I still have it after the rebuild. Its weird that it doesn't always do it. The smoke is blue correct?

 

The smoke is blue and has burnt oil characteristics and not coolant. Someone showed me the oil seal once and said that will also cause oil to be burnt on start up because it leaks out from the rotors through the seal when the car is sitting. I am just curious is that is the case why it does it sometimes. Perhaps someone who rebuilds engines knows what causes this.

 

I doubt it's your oil control o-rings, I have never seen one fail. Your culprit is probably your turbos.