Little puff of smoke on each startup

ldubmter

Member
Hi all,

I'm a new member and a new z4 owner (2010 35i). Just bought the car today. Super excited. Was showing it to a friend, who noticed a little puff of smoke when I started. I did a few tests, the little puff comes out every time. It's not cold or anything, so certain it's not just condensation. It wasn't blue so far as I could tell (too brief to identify) but I definitely got a burning oil whiff.

The smoke is just a single puff and then it's gone (and so is the smell). Is this normal (I'm guessing not). What are the danger signs I should watch out for? I did a little googling and came across a valve stem seal discussion and nearly passed out. Recommendations on what I should do?

Thanks!!!!
 
Hello and welcome, a picture of your car would be appreciated, we always like to see new owners Zeds :thumbsup:

Re the smoke , if not blue it’s unlikely to be valve seals. If white it’s likely to be water. How long was the car sitting before you bought it? Water/condensation can build up inside the exhaust and what you’re seeing may be it getting rid of that. Could be worth taking it for a proper blast, get some heat into everything and see if that makes a difference
 
Will get the pic up tomorrow, a little too dark now.

I put a good 30 miles on it, but it did probably sit a little. It was an auction car and has only had a couple hundred miles put on it since last July. Really tough to tell the color of the smoke because it's so brief, but it def had a burning oil smell.
 
Hi and welcome to the forum, a bit of a guess but the puff of smoke and oil smell could be from leaking oil seal’s in the turbos.
What’s the mileage?
Looking forward to seeing those photos :D
 
Valve stem oil seals are standard for this but they usually only smoke after standing for a reasonable length of time. That's possibly why it ended up at auction.
Have you checked for any MOT advisories?
 
Valve stem seals would cause this on start up, but I'd also get someone to follow you and see if you get it under harder acceleration, which could then point more to something like turbo seals.
You can also try putting a piece of paper across the end of the pipe when you start up. This may enable you to catch the cause of the smoke and determine if it is oil, water or fuel.
 
As above, I would expect the smoke to be a blueish tint.

If it’s the seals it would normally be worse on first start up in the morning after sitting overnight.

Maybe nothing but keep an eye on the oil level daily as it will soon drop if it’s burning oil
 
^^^This^^^ drive the car & see what the oil usage actually is between oil changes, if it’s negligible i wouldn’t be worrying about tearing the engine apart.
Rob
 
Blue smoke usually indicates oil is leaking somewhere as mentioned.
As a general rule white smoke could indicate a coolant leak, more specifically the coolant is getting into the engine, usually through a head gasket issue.
But if its just a small puff it is unlikely to be this. Bring it for a decent drive as suggested (70-80 miles) and see if its still doing it.
 
Chippie said:
Hi and welcome to the forum, a bit of a guess but the puff of smoke and oil smell could be from leaking oil seal’s in the turbos.
What’s the mileage?
Looking forward to seeing those photos :D

:thumbsup: :thumbsup: :thumbsup:
 
Just had someone follow me. She said it was white smoke only coming out of the left muffler. That seems weird, right?

I punched it a few times and she said the smoke stopped each time. She said it also completely stopped after a mile. Taking it for emissions. We'll see if it passes.
 
You will get condensation out of the left side on start up..that’s normal..right side only opened up under certain conditions

Oil smoke won’t cause an emissions fail normally unless it’s chronic

How many miles has the car done?
 
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