Since i've went de-cat, i've noticed that the car has started to get a bit smokey when ticking over.

However, it only happens now and again, sometimes it's fine, then other times it gets smokey. The smoke is kinda blue/grey.

Should i be worried ?

 

Does this only happen when engine cold? Or is it the same when hot?
If only when cold, may be the condensation is taking a while longer to clear due to lack of cat, which builds up a good heat source.
If still there when hot, the blueness could be residual oil lying on the cylinder bore sides whe the engine is stationary. So long as it clears within a few seconds, I would be reluctant to worry [yet].

 

Thanks for your reply.

It happens when hot.
It does clear, but that's only if i rev up, if it's still sitting on idle, it'll stay puffing away.

It's not a lot of smoke, but enough to notice if you know what i mean.
It's a 98 Uk car, and has done 69k.

 

Could be valve oil seals if thats the case, but so long as it does not get any worse, I'd leave alone till you need to get it sorted, as quite a big job to change them and you may want other bits doing anyway, so best to wait till then.
Good luck !

 

sounds exactly what I had. did it if u stopped in traffic etc.
sometimes would, sometimes wouldnt.

it was my turbo. the exhaust seal had gone, so it was dumping a tiny amount of unburnt oil into the hot exhaust causing the smoke.

replaced the turbo - no more problems

sorry!

Steve

 

Uh oh !

That dont sound good.

Car is going in for a check up in a few weeks. Think i'll get them to have a look.

The smoke isn't actually coming from under bonnet though, it's coming out the back..so i presume it's nothing dripping onto the exhaust.

Then again, knowing my luck...it could be both turbo and oil seals.

Is there any way of telling ?

 

Johhny

You using Octane Booster in there mate ?

I've noticed my shed is alot puffier on idle whenever NF or millers is used

Dunno why... it just does

Cheers
Si

 

Hey Si !

Nope, just using plain old Optimax i'm afraid.

 

Johnny,

Had exactly the same problem in MY01 WRX (decat turbo back) and it was the Turbo.

No more problems since it was changed - touch wood!!

Neil.

 

when I said exhaust seals, I ment the ones inside the turbo!
coz the turbo is fed oil, there are seals on the compressor & exhaust sides of it. when they go on the exhaust side, it pushes oil down the downpipe , which then burns a little, causing the smoke. but it's not like normal valve/ring smoke, which is really burnt, this is more fresh

but I'd guess it's that

quite hard to diagnose. check intercooler pipes for more than a trace of oil. check compression. if nothing there, then change turbo & see.

best of luck!
Steve

 

Sounds a bit like me turbo then.

Am in the middle of trying to purchase a new one (fingers crossed)

So when i change that, i'll find out either way i suppose.

Thanks for your feedback folks.

Will keep you posted.
Johnny

 

Can changing the DP cause the Turbo seals to go or can this happen at anytime?

Just wondering if the DP contributed to my Turbo going!

 

Good point...cos it's only been since i changed mine that it's started.

Not to worry, looks like i've got myself a VF34

Bye bye TD04 !!