Car Smokes at Idle Not the normal stories

[NickGT20]

Car smokes at idle but it's definately not oil or coolant. The smoke is almost definitaly fuel. The car is a 95 Talon Tsi Automatic almost stock. It came with a Forge Atmospheric BOV which would seem like the problem but swapping it to a stock 2g bov hasn't fixed the problem and i guess the stock one leaks because now the car feels slower. I actually orderd a dsmlink so I could log it and tune it, i know it's stock but it wont be for long and the logging is supposed to be good with the link. Any ideas on this guys? I was thinkig I'd be getting a MIL if it were a O2 sensor or something. Also the car never smokes during normal driving only at idle and usually it smokes when it's cold out. It's definately a sensor or something failing b/c the smoking is either all or nothing and it's totally random. A compression test yeilds 162-160-159-162 which I thought was acutally high since the car has 115k miles on it, maybe just some crap on the valves.

 

[brute]

Pull the intake and check for shaft play. It almost sounds like turbo seal(s).

 

[NickGT20]

How would turbo seals affect smoke that is caused by fuel? The car isn't buring any oil or coolant and this problem is getting progressively worse like turbo would but the shaft play hasn't changed is minimal. This has to be something probably a sensor in intake area i'm just not as dsm aware as the rest of you. I have an EFI mustang I race.

 

[brute]

How does fuel cause it to smoke?

 

[andytalon]

Smoke from Fuel=Black (Smells like un burn't fuel)
Smoke from Oil=Blue (Smells like burn't oil)
Smoke from Coolent=White (Smells sweet)
Smoke from Condensation=White (Only during start up)(Normal)

You must Recerc. your Bov because I have had smoking problems just from not having it recerc.. So give that a shot first, then we can go from there.

Have you done a boost leak test recently?? If so you can accually blow your turbo seals and it will smoke, or you could have just passed coolent through the seals during a test. Give me some feed back and more info and I will try my best to help ya.

-Andy

 

[brute]

I had white smoke only at start up. It was valve stem seals dripping oil into the combustion chamber. The oil would burn off at start up.

 

[NickGT20]

Yeah I do a lot of racing.(with a diffrent vehicle) It's unburt fuel causing it to smoke only at idle and usually when the engine is cold, any throttle even if i rev it to say 2k sitting still no load will stop the smoke. Something tells me turbo seals are not causing me to smell gas and get black smoke which i know is unburt hydrocarbons. Yes I have done a boost leak down test recently the only thing that leaks is the TB seals, if you guys tell me where to get them I will buy them. Would leaking boost really cause a bunch of unburnt fuel at idle though and nothing during WOT or partial thorttle? I think when the DSM LINK gets here i'll know a lot more b/c I can log what's happening hopefully. My guess is whatever fuel map or sensor the IDLE works off of if it's not the MAS than it's getting less air than the car thinks it is and it's adding fuel to compensate... For instance in the mustang MAS metered cars we often have issues with MAF sensors getting oil from K%N filters on them and fouling... Usually it's not permanet and all that is needed is some gentle contact cleaner and a paper towel. Even that though it's a LOT of fuel.. Smoke is really bad and like I said it's hit or miss, nothing or everything. Thanks for the help If anybody knows it's you guys.

 

[NickGT20]

Andy Talon I did recer the BOV.. Sorry. The first post was a jumbled mess I was in a hurry. I used a stock 2g plastic POS bov which aparently leaks because the car dropped like 3PSI after I installed it.

 

[brute]

Does the smoke ever go away? Does the engine run fine? Does it drive fine?

 

[NickGT20]

Engine runs fine, smoke is only at idle and only sometimes. Typically when I go to work in the morning and it's colder out i'll see smoke and it's heavy but as soon as I put it in gear and apply gas there is no more smoke. Little update for everybody I ran the OBD scanner and I have a P1400 MAP sensor although I never had a CEL so I thought maybe it's old i've probably never cleared them and I've only owned the car a year. I cleared it and drove arround for a while and sure enough it came back, and again no CEL. And the CEL light does work... strange. I'm going to do the MAP sensor voltage test.. I think it's .8 volts idle and up to 2.4 when reving it or something on pin 1.