911 heating system problem

[ehsiceland]

Hi there
I have a Porsche 911 Carrera 1989, and when I turn on the heating knob between the front seats it seems to let some exhaust smell in to the car. When I turn the knob to "0" position the smell goes away. Can someone tell me what is causing this? There is no visible oil leak from the car.

Best regards, ehsiceland

[DRACO A5OG]

Hey EHS,

Well does your front footwell blowers work? If so it may be the blowers motors that are going bad, possibly rubbing against the internal parts do to worn bearings.

It could also be the engine bay heater motor as well.

Another thought is if in fact it is exhaust, do you have an exhaust leak in the engine bay? Air source is from your engine area.

BTW, Welcome Aboard!

[ehsiceland]

Hey Drago!

Thank you very much for your answer and information. I will check these things out but it smells actually like hot oil in the car. And as I said, no visible leak of oil and it goes away when I turn off the heater, and that is not an option in Iceland ;-)

Best regards,

EHS.

[jimmcc]

Check for a small oil leak that is dripping oil on the top of the headers or heat boxes. They often excape notice. The oil smell is coming as the oil burns and is picked up by the heater air intake. It doesn't take but a but of oil to create a massive stink. Normally, if the leak is small it will burn off as you drive the car and the smell will decrease.

Jim

[ehsiceland]

Tanks for that, and I think you were right, I found a small leak coming from an axel boot. Gess itīs normal for a 20 year old even thoug it has only 50k miles on.