white smoke out exhaust on the way home tonight

Jeff NJ · 06-21-2016, 03:39 PM

So I sat in a lot of traffic tonight on the way home. Temp didn't even get to the second line, so it wasn't overheating, but a couple wisps of smoke caught my eye in the rearview window as I was plodding along in bumper to bumper traffic. Eventually got moving and that's when I noticed a LOT of smoke. It really was only noticeable to me when I would let off the gas. I wasn't on boost, just maintaining speed, and when I would let off, a thousand mosquitos would die. I figured turbo seals.

Well, I got it home no problem and let it idle for a couple minutes. No visible oil leaks and no smoke in exhaust either at idle. I did notice the AFR gauge showed a little lean at idle. 15.2+/-. I ate dinner and then went back out and started it. It fired up immediately and there was zero smoke. I let it idle and the AFR started creeping up to about 16! I revved it to about 2500rpm a few times. No smoke, ever. So I turned it off and am not sure where to look next.

I would think if it was turbo seals, it would smoke on startup after sitting for an hour or so, and the AFR would be unaffected. Surely, they could be unrelated, but my AFR's are quite consistent up to now.

Oil pressure and levels are good and haven't added oil in a while.

thoughts anyone?

speednme1 · 06-21-2016, 04:14 PM

Not sure what it could be but I would appreciate it if you would drive down to my house and kill these damn mosquitos ...

Jeff NJ · 06-21-2016, 04:26 PM

Quote:

Originally Posted by speednme1

Not sure what it could be but I would appreciate it if you would drive down to my house and kill these damn mosquitos ...

Haha Rey. I've got enough of my own to kill here!

gsxrken · gsxrken's Garage

When turbo seals go it's usually millions of Mosquitos that die. Unfortunately if your symptoms were worse on decel that sounds like ring seal or exhaust valve guides drawing down oil under high vacuum. What is the history of the engine, do you know?

Rawknees'Turbo · 06-21-2016, 05:22 PM

Hey Jeff, I don't want to be an alarmist, butt remove the oil cap on the tank and see if there is a lot of oil smoke/vapor coming out of the fill neck; normaly there is quite a bit wisping out when the oil is hot (not clouds, butt easily seen with a flashlight in low light of garage or at night), butt actual puffs would indicate excessive piston ring blow-by which can lead to smoking.

Also, turbocharger seals that leak into the exhaust create an insane amount of smoke (like the two goons above mentioned), butt leakage into the intake (not like THAT) results in intermittent smoke - maybe remove the intercooler and see if there is excessive oil in the compressor throat (always some, like a general wetting of oil on the surfaces, butt should not see oil pooled up around there).

speednme1 · 06-21-2016, 05:52 PM

Quote:

Originally Posted by Rawknees'Turbo

butt leakage .

Hmmmmmm......you would know

Rawknees'Turbo · 06-21-2016, 05:59 PM

^^^

Ha! I floated that choice layup and didn't even realize it! Way to go, Rey!

Speedy Squirrel · Speedy Squirrel's Garage

White smoke is raw fuel in the exhaust. Something is happening to the control pressure, or the air metering plate is sticking.

CASair · 06:15 PM

white smoke is oil, black smoke is running rich. I'm with Gsxrken, rings or valve guides, oil gets sucked into combustion chamber on decel.

Next time you have the engine warmed up, rev it high (6k rpm in 2nd or 3rd gear) and let it coast down (still in gear) to about 2500, then hit the throttle and look in the rear view mirror. If you just killed a million mosquitos it may get expensive.

Do you have history on the engine? miles on the car? More info would help!

speednme1 · 06-21-2016, 06:31 PM

If in doubt, get a leak down and a compression test. May not be as bad as you think.

Jeff NJ · 06-21-2016, 06:48 PM

~60k on the motor. No rebuilds to my knowledge and I do have a lot of receipts.

I can do compression, butnot leakdown.

Jeff NJ · 06-22-2016, 06:47 AM

So I guess I'll try the easy stuff first. I'll pull off the IC and see what I can see in there and if it is filled with oil. I'll pull the oil tank cap and see what comes out and then I'll drive it and see precisely when I start sending out a smoke screen.

I'll check compression. If that is good, I guess leakdown test would be next?

Thanks for the help.

smurfbus · 06-22-2016, 07:21 AM

Does it puff white smoke after longish periods of no running? Mine did and there was ring problems and exhaust guides were also really worn even though they were 5000 miles old? Ive read that guides can be installed wrong and then they squash but thats not likely your problem but milage might suggest new guides.

Mine was white smoke and rreeaally bad for neighborhood. Im glad it went a way after new rings and worked heads.

Jeff NJ · 06-22-2016, 07:36 AM

Quote:

Originally Posted by smurfbus

Does it puff white smoke after longish periods of no running? Mine did and there was ring problems and exhaust guides were also really worn even though they were 5000 miles old? Ive read that guides can be installed wrong and then they squash but thats not likely your problem but milage might suggest new guides.

Mine was white smoke and rreeaally bad for neighborhood. Im glad it went a way after new rings and worked heads.

It really was essentially smoke free before yesterday. No smoke on startup and I had never seen any real smoke on accel, decel, or any other time. I would think if the valve guides were wearing over time, it would gradually increase, but this went from nothing to smoke screen inside of 10 miles and about a 1/2 hr of traffic.

I'll start it again tonight and see what happens. I am getting ready for a golf trip to upstate NY, so I cant spend a lot of time on it until later next week.

Do I do compression checks with a warm or cold engine?

mreid · 06-22-2016, 07:47 AM

Congratulations, you've elected a new pope!

White smoke is steam, but that makes no sense. Next is oil, which with a turbo is rarely good news. Good luck with your diagnosis!

Jeff NJ · 06-22-2016, 07:22 PM

So I pulled the IC off and looked inside and like Rawknees said, very light film, no puddling of oil. No way the turbo seals are shot.

Next I pulled the plugs so I can do compression test tomorrow when I have help. I have lined them up below #1-6 from left to right. I don't think they look bad. #2 is a little wet, but it smells and looks like gas, not oil.

What say the experts at looking at plugs?

smurfbus · 06-22-2016, 07:59 PM

Looks like it might still be the turbine side of the turbo?

Jeff NJ · 06-22-2016, 08:04 PM

Quote:

Originally Posted by smurfbus

Looks like it might still be the turbine side of the turbo?

Wouldn't that smoke like a banshee at startup though since oil would be in the exhaust? No smoke at all when I started it tonight before I took the IC off.

Rawknees'Turbo · 08:19 PM

I'm no expert on spark plugs (ask Rey about all manner of "plugs" - at your own peril, buttofcourse!

), but none of them would give me any cause for concern and definitely don't show signs of low compression use.

Typically, oil in the turbine causes massive smoke (have seen this with my own car, unfortunately), like you would think the car was on fire, so I don't know what next to guess. If it were mine, I would say the hell with it, drive it as normal, and see if the smoke deal happened again or got consistent/worse. Sux always wondering about stuff like that, though.

Valve guides possibly, as others have mentioned, but a compression test isn't going to tell you jack shart about that and a leakdown wouldn't either unless one of the guides was so worn that the valve was not seating properly (not likely).

Rawknees'Turbo · 06-22-2016, 08:37 PM

Had another thought (the 2nd one for today!!!); probably be worth your time to test the function of the scavenge pump (pretty easy to do and lots of instruction in past threads) - maybe the drive pin is starting to get worn and was not keeping up in the conditions you mentioned.