Smoke/Burning Smell through vents

[Scott79]

Hi,

We have just had smoke coming through the air con vents.

Every now and again a bad burning smell. Mechanic cant find any faults?

Can anyone help? 

Thanks

Scott.

[cliffcoggin]

What does the smoke smell of? What colour is the smoke? The stink of burning electrical insulation and that of exhaust fumes and that of scorched coolant are very different. If you do not know the difference it is not advisable to use the car until it is fixed.

You have not mentioned the fuel, so be aware that the fire risk is much greater if your car is fuelled by petrol than diesel. Diesel is surprisingly hard to ignite.

[Scott79]

HI,

Thank you for your reply

Its a Diesel, smells more like exhaust fumes?

Scott.

[cliffcoggin]

And what colour is the smoke?

[Scott79]

HI,

Smoke is white.

Smell is giving my partner headache. Strong smell.

Thanks
Scott.

 

[cliffcoggin]

I reckon white smoke rules out electrical insulation burning because that would be brown, so that leaves exhaust fumes and scorched glycol (coolant).

If the exhaust is leaking to the extent of filling the cabin with fumes I would expect you to be able to hear a lot more exhaust clatter than normal, and possibly even see or hear the gas escaping if you put your head under the car. Is that so?

If the cooling system is leaking I would expect a need to top up the radiator header tank frequently, and possibly overheating of the engine. Is that so?