Any suggestions to why my car blows out white smoke from time to time when its hot?

[jjj751]

I recently moved to the Vegas area where we experience 100+ degree heat pretty much every day in the summer. Not too long after moving here I would get a lot of black smoke when I accelerated, as if I had a diesel. Turns out I had a blown turbo. After replacing the turbo and the rear coolant flange (leaking coolant), as well as new plugs, I am getting a new issue. After leaving the car in the sun and I accelerate on a 100+ degree day with a passenger, I notice that the car is not as peppy as it usually is, and on occasion I would hear this thumping/clicking like sound from the engine and a plume of white smoke would come out the exhaust. No CEL but when my shop plugged in their more advanced OBDII reader (not vacgom) it read a misfire on cylinder 3, replaced the coil and cleared the code but the symptoms still persist but code is no longer there. It was an aftermarket coil but I am switching out all the coil packs with genuine audi ones tomorrow. It seems to happen when its 95+. I don't believe its a cracked block or head gasket as it doesn't seem like I'm losing coolant. Anyone out here in Vegas or lives in these conditions ever have these issues? Any opinons?

[67Twisty]

I would have guessed leaking head gasket if not for your other symptoms. Condensation in tail pipes at start-up would not be uncommon in more humid climates but not in Vegas. With the cylinder misfires, it could be a faulty fuel injector and/or faulty coil pack. Problems with either could cause unburned fuel to vaporize and be seen as white smoke through tail pipes. If your timing is off due to coil pack/ignition problems, you will get engine bog symptoms and could have preignition. I would also check the condition of your plugs and try to scan with vag com for more info.

[jjj751]

I would have guessed leaking head gasket if not for your other symptoms. Condensation in tail pipes at start-up would not be uncommon in more humid climates but not in Vegas. With the cylinder misfires, it could be a faulty fuel injector and/or faulty coil pack. Problems with either could cause unburned fuel to vaporize and be seen as white smoke through tail pipes. If your timing is off due to coil pack/ignition problems, you will get engine bog symptoms and could have preignition. I would also check the condition of your plugs and try to scan with vag com for more info.

Thanks for the input. Wouldn't a faulty injector mean issues right from start up? The car seems to drive fine when I take it out of the garage in the morning. It's just after it warms up and has been sitting in the sun for the day that I start to feel it bogging down and on occasion the white smoke while bogging down.

[67Twisty]

I doubt it's the injectors but it something to look into if you don't have a coolant problem and your cylinder head checks out. Lean fuel conditions caused by clogged injector would usually show as more gray rather than white smoke. It's also more common on the TDI engines. It's the engine misfire/bog condition combined with the white smoke that made me think water in cylinder. Checking the condition of your plugs may also give you a clue if there's a leak or if you have timing problems. I'm a hobby mechanic and work on older carbureted cars more than on modern cars like my B7, so if it was mine I'd get it checked out by a good Indy shop that knows VAG. Did you swap in the new coilpacks?

[jjj751]

I doubt it's the injectors but it something to look into if you don't have a coolant problem and your cylinder head checks out. Lean fuel conditions caused by clogged injector would usually show as more gray rather than white smoke. It's also more common on the TDI engines. It's the engine misfire/bog condition combined with the white smoke that made me think water in cylinder. Checking the condition of your plugs may also give you a clue if there's a leak or if you have timing problems. I'm a hobby mechanic and work on older carbureted cars more than on modern cars like my B7, so if it was mine I'd get it checked out by a good Indy shop that knows VAG. Did you swap in the new coilpacks?

I'm pretty sure it was white and not grey but I was looking through the 20% tints on my rear window . I'll have my shop make sure its not coolant. I did get new coil packs in from Europaparts today but unfortunately all of them were either bent up at the tips or looked like they were coming apart. Gotta wait till at least Tuesday to put them in my car if they are willing to rush replacements to me. Have new plugs waiting to go in with them as well. In the mean time its almost normal in the morning out the garage, its just coming home after the car has been sitting in the heat that I feel like its not as peppy (heat soak maybe?) which is what usually leads to the smoke, so now I take it easy on the pedal so I don't smoke screen the cars behind me. Didn't know these cars would be brought to its knees in this heat.

[67Twisty]

You could have multiple unrelated things going on. Yes - temps you describe can cause heat soak on these cars. I've never been a fan of the way Audi designed the air intake passing over the turbo and adjacent to the exhaust manifold. We get temps close to 100 here with high humidity, but I've never noticed a big issue with heat soak. Bad diverter valve can also cause the sluggishness but I'm assuming this was replaced when your turbo was replaced. What's your mileage? Carbon deposits on the intake valves can also cause this and could also result in cylinder misfires. It may be time for a carbon cleaning.

The smoke issue is hard to diagnose so you'll need to go through process of elimination. If your head gasket is fine and there's no coolant leak, you can move on to oil or fuel related items. Pulling plugs and checking for sticky fluid, gummy threads is a good test for for coolant seepage. You can also check the tips for rich or lean burn conditions. Hopefully it's just a coilpack issue and the new coils remedy the problem. Since you seem to have no issues at start-up when cold in the am, it's likely not a valve seal problem. It also rules out simple water vapor in exhaust as this would be seen as white smoke/vapor at start-up. Smoke under hard acceleration often indicates worn rings in higher mileage cars and would normally be grey/black in color. Compression/leak down test is needed to diagnose.

Start with the plugs and coilpacks and go from there. Hopefully the smoke does not return and your sluggishness is heat soak only. Good luck!

[jjj751]

You could have multiple unrelated things going on. Yes - temps you describe can cause heat soak on these cars. I've never been a fan of the way Audi designed the air intake passing over the turbo and adjacent to the exhaust manifold. We get temps close to 100 here with high humidity, but I've never noticed a big issue with heat soak. Bad diverter valve can also cause the sluggishness but I'm assuming this was replaced when your turbo was replaced. What's your mileage? Carbon deposits on the intake valves can also cause this and could also result in cylinder misfires. It may be time for a carbon cleaning.

The smoke issue is hard to diagnose so you'll need to go through process of elimination. If your head gasket is fine and there's no coolant leak, you can move on to oil or fuel related items. Pulling plugs and checking for sticky fluid, gummy threads is a good test for for coolant seepage. You can also check the tips for rich or lean burn conditions. Hopefully it's just a coilpack issue and the new coils remedy the problem. Since you seem to have no issues at start-up when cold in the am, it's likely not a valve seal problem. It also rules out simple water vapor in exhaust as this would be seen as white smoke/vapor at start-up. Smoke under hard acceleration often indicates worn rings in higher mileage cars and would normally be grey/black in color. Compression/leak down test is needed to diagnose.

Start with the plugs and coilpacks and go from there. Hopefully the smoke does not return and your sluggishness is heat soak only. Good luck!

Yeah I'm gonna do that when the coils come in and I'll start from there. Currently at 90,000 miles. The piston rings were replaced by the dealer at around 50,000 miles after i had excessive oil consumption. Yeah the diverter valve came with the new turbo. When I had the bad turbo the plugs were all black at the tips and the shop said it was because of the turbo

http://images.tapatalk-cdn.com/15/07/19/5478d2195810b319c391ca06c5620720.jpg

Yeah due to having no issues on a cold startup hopefully it's nothing too serious.






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[67Twisty]

fWIW

Sounds like symptoms similar to what you are describing:

http://www.audizine.com/forum/showthread.php/656669-white-smoke-metallic-rattle-noise-under-load

[jjj751]

Thanks bro, similar symptoms for sure. Oil consumption is pretty high again as well. Gonna look into it.


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[jjj751]

So update on this issue. Turned out to be the valve cover. Took us weeks to figure it out but we changed out the PCV and it was still dumping oil in the intercooler hoses. Changed the valve cover and oil levels haven't dropped at all after 2 weeks. Car doesn't smell like hot engine oil after parking it in the garage.

An issue I do have now however is I feel a lack lack of power after the cars been sitting in the sun on a hot day. Out here it's 100 degrees every day. When I drive to work in the morning the power seems to be there but when I drove home from work after the cars been in the sun all day I don't feel the whole 200 horsepower. Definite difference. Gonna change the plugs soon since the valve cover probably fouled them up.


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[A-BlacK_MambA-4]

Your sluggishness would be something called heatsoak lol. Which means a bigger/more efficient intercooler and or water methanol injection to combat it. Those will help some, but when it's 100+ degrees any car will feel more sluggish than when the temperature is cooler.