Audi A4 Cabriolet - Strange smell through car vents

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Sat 5 Oct 2019 15:23
Audi A4 Cabriolet - Strange smell through car vents - Rustydog
Hello everyone. I would really appreciate some help with this.
my car has a strange oily smell coming through the car vents inside the car. It seems very strong when the car is stood at idle, when it’s on the go I can barely smell anything.
I have put some engine cleaner in and about to get the oil and filter changed again but I am not sure that’s going to fix it.
I have spent a small fortune recently fixing an oil leak, changing rocker cover gasket, new front exhaust pipe , new timing belt and water pump (not to mention a new clutch)
This problem of an interior smell through the vents has been there all along with none of the above work making any difference
This morning the EML light came on and the code showing is PO171 engine running lean.
My mechanic now wants to remove hoses and inspect and clean in case there is a leak somewhere ?
Many thanks
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Sat 5 Oct 2019 16:10
Audi A4 Cabriolet - Strange smell through car vents - Falkirk Bairn

Use a deoderant fabric / air type spray. I have used Oust before.

For a better insight

https://www.wikihow.com/Eliminate-Odor-from-a-Car-Air-Conditioner

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Sat 5 Oct 2019 16:50
Audi A4 Cabriolet - Strange smell through car vents - elekie&a/c doctor
There are lots of engine breather and vacuum pipes on these . Could be a small split somewhere enough to cause oil vapour fumes . Also check the oil filler cap seal and engine dipstick tube for leaks . The p0171 code is a lean burn condition , possibly as a result of an air leak somewhere. If you garage has access to a smoke test machine , this would help locate the problem.
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Sun 6 Oct 2019 12:21
Audi A4 Cabriolet - Strange smell through car vents - edlithgow

To state the obvious (sorry) an oily smell suggests an oil rather than a vacuum leak.

I wouldn't expect a vacuum leak to smell of anything, unless it was causing lean-burn overheating.

I suppose this is a distant possibility, but I'd bet the smell and your fault code etc are unconnected.

Are you sure its an oily smell?

For example, small coolant leaks have a sickening burnt toast sort of smell, and various plastics in cars gas-off trace organic solvent sort of odours.

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