I have a '92 525i and I notice on occasion when I turn on the air conditioning, there is a strange odor like burning leaves. It happens on occasion, not all the time. Is this something to be concerned about? What might be causing it? I checked, there are no leaves in the engine bay. Thanks!
"Scott" wrote
Does that thing have a cabin air filter? If so, when was the last time you replaced it?
Also, it is quite possible you have mold/fungus growing in your vent system. It happens occasionally. There are products out there that you spray into the ifresh air ntake to kill the fungus and clean the ducts.
Cheers,
Pete
clearly your a/c is overheating (as happened to mine) and is burning away mould growths on the inside of the vents, it's only a matter of time before the temperatures rises and plastics catch fire (as happened to me) this was not covered by my insurance policy, My advice would be to turn off the A/C untill its serviced by a tech.
T
There isn't much that would cause that sort of odor, perhaps a sticking belt or misaligned pulley? Check the AC belt.
When you smell this, is it coming from the vents, or is it more prevalent in the engine bay at the time?
-Russ.
I'd describe the smell I get as more like stale cigarette smoke. Disgusting. Would this possibly be near it?
If so it's mould growing on the AC heat exchanger. If you turn it off a few minutes before stopping it helps prevent this, or you could try a deodorizing spray you use in the air intake.
There are specialized types, but in the UK Febreeze - something you spray on curtains etc to remove room smells, seems to work ok and is cheaper.
Your A/C microfilter needs replacement (I usually describe the smell as burnt twigs but I know what you mean). It has happened on my previous 328i and my latest 330i.
To fix it in the short term, open the bonnet (hood if you are American) and undo the two screw clips holding down the "plenum chamber" cover (at the top of the engine compartment); remove the filter which is inside and bash it against a wall a few times to remove some of the grot in it. Replace it and all will be better for a few weeks / months.
To fix it in the longer term, remove old filter and replace it with a new one --- smell gone (for about 18 months).
Hope this helps,
Roger, Aberystwyth
Are you saying that microfilter only works with the AC on? On my E39, the twin microfilters work on either heating or cooling when in fresh air mode, so surely would produce this smell all the time? But with me it's only with the AC in use, and only for a short while after switching it on from an overnight or long stop.
Dave,
That's exactly the symptoms which I had on my last 2 BMWs. The "whack it on a brick wall" to try the cure only takes about 5 minutes and would indicate if this is the cause of your problem and then you can replace the filter if the temporary work-around works.
Cheers,
Roger, Aberystwyth
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