Scooby125

Just noticed yesterday on my version 2 sti ra that on start up that I see a small puff of smoke out the back. I never noticed this before. What could the reasons for this be. I just changed the oil but its not overfilled.
Would using too much octane booster have anything to do with it??

I only noticed this for the first time on Sunday last and I dont think it has done it before as I reverse out of the garage and think I would have noticed it.

On Friday night I changed the oil to Silkolene Pro S 10w50 but apart from that I dont think there was any major changes.

I was at a Subaru specialist on Sat just to give the car the once over and this is prior to seeing the puff of smoke the next morning but he said the car was A1 and enfine quiet etc.

He then took the car for a blast and I mean he drove the cr*p out of it to test drive it and on very high revs he was getting a flicker of the forth amber light. He came back then and just turned off the engine fairly soon. I was a bit annoyed because the engine was only slightly warm after he trashed it and also didnt give it qa chance to cool down.

On the journey home I gave the car a chance to warm properly and then gave it a good lash of the throtle up through the gears and the most I could get was a flicker of the second green once the the car was warm.

I hope the puff of smoke and last Saturday are unrelated? Also what do you make of the forth amber flickering when the car was not warmed up. Would this be a reason? The car is standard apart from a rear exhaust and I run it on SUL plus a good bit of NF booster. Just to add that the puff of smoke smells very muck like petrol (I think).

The car is only in from Japan a couple of months.



Cheers.

Gear Head

iTrader: (2)

If its white smoke, and it dissappears when the engine is warm, it could be moisture in the exhaust. Nothing to worry about.

Mr Pants!

My 03 STi when cold has a very nasty rich smell that comes out of it and what looks like smoke, it is definitely not condensation. However, once it is started it goes away, it is just the initial start.

ricardo

Mine does that (MY98) if it has been cold at night. It just overfuels for a second or two and you see a haze of smoke a few seconds after starting. In my case I notice it because I reverse out to start with. Smells bad, but not like burnt oil.

I've had it left overnight at a dealer, they confirmed that it was fuel not oil, and couldn't really see any particular cause worth fixing.

Mine has done it for years whenever started after a frosty or very chilly night, and no harm seems to have occurred.

Scooby125

What do you think the cold temp has to do with the overfuel and what causes the over fuel in the first place?
Cheers.

Mr Pants!

I think when engines are cold they restrict the amount of air to fuel mixture to mostly fuel and less air. Whats called a rich mixture not sure why it would produce a puff of smoke, but I think that is what it is.

ricardo

From a cold start there is a rich mixture, especially in the first few seconds. If some sensor is making the enrichment worse then colder probably equals more enrichment. I guess that in my case it is a bit too rich, temporarily, and it overwhelms the cat such that the partially burnt fuel ends up in the exhaust. Only ever a second or two of smoke (or 'haze of unburnt hydrocarbons'). Maybe the cat is tired, and would deal with this otherwise, but it still passes an MOT fine when warmed up.

Scooby125

Thanks lads,

I only noticed this for the first time on Sunday last and I dont think it has done it before as I reverse out of the garage and think I would have noticed it.

On Friday night I changed the oil to Silkolene Pro S 10w50 but apart from that I dont think there was any major changes.

I was at a Subaru specialist on Sat just to give the car the once over and this is prior to seeing the puff of smoke the next morning but he said the car was A1 and enfine quiet etc.

He then took the car for a blast and I mean he drove the cr*p out of it to test drive it and on very high revs he was getting a flicker of the forth amber light. He came back then and just turned off the engine fairly soon. I was a bit annoyed because the engine was only slightly warm after he trashed it and also didnt give it qa chance to cool down.

On the journey home I gave the car a chance to warm properly and then gave it a good lash of the throtle up through the gears and the most I could get was a flicker of the second green once the the car was warm.

I hope the puff of smoke and last Saturday are unrelated? Also what do you make of the forth amber flickering when the car was not warmed up. Would this be a reason? The car is standard apart from a rear exhaust and I run it on SUL plus a good bit of NF booster. Just to add that the puff of smoke smells very muck like petrol (I think).

The car is only in from Japan a couple of months.

Cheers,

Scooby125

bttt

Scooby125

bttt