Strange (burning) smell on cold start up

[kozmos]

I've recently noticed a strange foul burning smell coming from my engine bay after starting my car from cold (overnight).

I usually smell it after 3-5mins of driving after a cold starts and it's particularly obvious when I stop at a traffic junction after a short drive. So obvious that the smell even comes into the cabin via the aircon ducts during this 3-5mins of driving.

My car drives normally, all gauge readings are normal, What's going on??

HELP S4friends

[kozmos]

I forgot to mention, I cannot detect any smoke from the engine bay or any part of the car and the smell dissapears after a long drive (over 15mins)

[UKS4APR1]

Sounds like the "cats" coming up to temp and starting to work, or a spot of oil on same getting superheated as they start to work.
If so it's "nothing to worry about" (famous last words!)

[Mc-BigE]

I had a similar problem about 2 months ago, a plastic burning smell, turned out to be a big black plastic bag that stuck unto the middle of my exhaust under the car! Bitch of a job to get off!. I noticed the smell normally after a small journey, not at the beginning obviously!
Yours sounds different, but it’s no harm to have a look underneath.

[BaSen]

Who the FECK puts a plastic bag under your car?! The person must've been really jealous... Good thing it was "only" a bag.

Haven't had the problem you're having.. Had some ugly smell a couple of months ago aswell. Turned out to be the GPS causig a minor fire (stereo burned, all electric cables melted) Good thing there's insurance for those kinds of things

[springfield]

I would opt for a minor oil leak getting onto the exhaust and burning off on start up! check the floor after the car has been standing for oil and get it on a ramp to check underneath.
HTH Jim.

[Mc-BigE]

I was on a dual carriageway when the plastic bag went under the car!
I couldn't avoid it because there was a car next to me! I though no more of it until the following day! when I smelt the burning plastic smell! (Didn’t realised it had stuck to the underside of the car when it happened)
Anyway, getting slightly off the thread topic here!
hope you find your smell kosmos!

[kozmos]

I just got my car back from a 30,000mile routine service inspection and the burning smell coming from my car was diagnosed from and oil leak between the engine and transmission seal. It's not actually dripping with oil, but there is oil seepage from the seals and is dripping onto the hot exhaust, this explains the smell during cold start. My mechanic didn't recommend I remove the transmission from the car because he doesn't think the leak is serious enuff to warrant removing it.

When the car sits overnight, some oil drips onto the exhaust and when i drive it in the morning, after a short distance after the exhaust heats up, the oil burns on the exhaust, hence the smell. The smell is only noticable when the car is stationary, you can't smell it when its moving.

Anybody with similar oil leak issues on their S4? Is it serious? What should I do?

[gavsteryoung]

I have a similar thing going on, but its just the rocker cover weeping slightly. It drips off the rear of the head and drops onto the exhuast or turbo.....

A lot of S4's do the same...... seems to be a common problem.....

So yours could be that rather than the engine transmission link....

[s4dan]

today when i was changeing a clutch in a 2.7 biturbo a6 i noticed that the burning smell is of the over flow for the headder tank it has a black ova flow pip that gose down the back and gess wot it tuches the n/s turbo yep it gets hot and melts it! my s4 dun it to