puff of smoke on startup
 

Something has recently developed with my sti.

On startup occasionally the car will make one puff of white smoke. Usually after sitting for several hours. Now i know it is oil, but just want to work out where it is coming from.

The engine itself appears to be in good condition. There is minimal blowby, and all the plugs look perfect. Compression is all ok. The car doesnt smoke at any other time, even if left idling for long periods, which rules out valve stem seals. The engine can be revved for long periods and produces no smoke. THe engine run with the oil cap off doesnt produce any blowby out of the ordinary. and almost creates a vacumm when revved. Which rules out rings.

There is a oil film in the bypass valve pipe, and the wastegate control lines, aswel as a slight film in the crankcase PCV line.

When the intercooler is removed there is oil in it, which sugests that either the oil is getting in there from the turbo or blowby.

Now i guess my question is how common are the vf28 turbo's to fail? Is it possible that the oil that is in the intercooler pooling on my throttle plate is causing this occasional puff of smoke?


THanks

Tom

I get same thing. Have swapped out turbo with brand new one and new seals and still same. I'm getting catch can next.

Have done comp test and cylinder leak test and all fine.

turbo seal

[QUOTE=WhiteRX]Something has recently developed with my sti.

On startup occasionally the car will make one puff of white smoke. Usually after sitting for several hours. Now i know it is oil, but just want to work out where it is coming from.

The engine itself appears to be in good condition. There is minimal blowby, and all the plugs look perfect. Compression is all ok. The car doesnt smoke at any other time, even if left idling for long periods, which rules out valve stem seals. The engine can be revved for long periods and produces no smoke. THe engine run with the oil cap off doesnt produce any blowby out of the ordinary. and almost creates a vacumm when revved. Which rules out rings.

There is a oil film in the bypass valve pipe, and the wastegate control lines, aswel as a slight film in the crankcase PCV line.

When the intercooler is removed there is oil in it, which sugests that either the oil is getting in there from the turbo or blowby.

Now i guess my question is how common are the vf28 turbo's to fail? Is it possible that the oil that is in the intercooler pooling on my throttle plate is causing this occasional puff of smoke?


THanks

Tom[/QUOTE]
Tom, it could be chucking oil up into the intercooler which would result in occasional white smoke on startup. Check vacuum lines also.
try removing the intercooler and flushing it out with degreaser. An oil catch can may also assist.

[QUOTE=nauli]Tom, it could be chucking oil up into the intercooler which would result in occasional white smoke on startup. Check vacuum lines also.
try removing the intercooler and flushing it out with degreaser. An oil catch can may also assist.[/QUOTE]

Flushed out the intercooler. I would plan on fixing what ever is causing the problem rather than putting in a catch can.

All the lines are ok.

Could it be the valve guide stems?? I know this is usually the cause on a normal motor but not too sure if boxers are affected the same way.

[QUOTE=WhiteRX]Flushed out the intercooler. I would plan on fixing what ever is causing the problem rather than putting in a catch can.

All the lines are ok.[/QUOTE]
It may have built up over time...see how it goes. They can chuck a bit of oil up even if they're relatively healthy.

i have the same problem on my 04wrx. i think its turbo failure buddy. how much oil is ur car burning? I'm burning a little over a litre to every 1000k's !!! the turbo seals were changed and still the same problem.
the turbo is burning too much oil and the left over is getting chucked out on start up.....
originally i thought something to do with the valves but very unlikely as my motor hasn't done many km's...
monitor ur oil levels.. i'd say ur in the same boat as i am.

proberly about the same, well a bit less oil. I would say 1L every 2500km. which is excessive for what i would expect.

My last rex with 140000km on it burnt 1l every 4000km, so i was happy with that.

When i spoke to our turbo supplier, they said dont bother getting it rebuild, as most times it doesnt fix anything. Just get a new one

Steve i get the feeling from your posts that the little bit of smoke/oil is normal. Since you have had a few sti's howmuch oil have yours used? any smoke, because i do understand that sti's are completely different to a rex in many ways, so i dont know.

My colleagues seem to think that i should wait a bit, but it is kind of embarrassing when people see it :) Is only for a second though. I know with porsches they do this a bit, and most people accept it as their character..

Ok. Update. about 2 weeks after putting back in 10w oil. the smoke has stopped. Proberly stupid of me to try a 5w oil anyway. It is too thin for my car, even says it in the manual.

So looks like it is back to normal :)