Get chemical smell out of car? Help?

A

asus389

New member
I am the new (to me) owner of a 2011 BMW 328i. The car is great, but it has been plagued by a chemical smell that comes out of the vents when the heat or AC is run. It is kind of subtle at first, but if I run the vents with the windows closed on a longer drive it eventually makes me dizzy, my throat starts to hurt, and sometimes I will get a headache. If I don't run the vents (system totally off) and just roll down the windows, the smell dissipates fairly quickly and I don't feel sick. I live in a state with cold winters and hot summers, so not using the heat/ac system isn't really an option.

The car has been inspected several times and the mechanics can't find a fluid leak that is responsible for the smell. It doesn't smell like mold in the AC, which is a problem I have had on past cars. It has been suggested that someone might have tried to de-odorize the vents with a chemical prior to my owning the car, and somehow the smell is stuck in there.

Has anyone run across anything like this before? Is there a way to pinpoint where the chemical smell is likely coming from or what it is? How would you go about cleaning out the vents in a way that doesn't add more chemicals to the system?

thanks for any suggestions
 
is the a/c still working ok? a slight leak in the a/c evaporator core can sometimes put Freon into the cabin, at least it did with my 2000 ford pick up.
 
I'm guessing it's a leak dripping on the hot engine or exhaust ... either oil or antifreeze... or even trans fluid.
I had a faint smell coming into my car ended up being a bad intake leaking antifreeze.

If you sit in the car after it sat all night with the windows up.. turn on the vents and sit back.. listen to some music. Does it smell then? If it does.. it's in the vents.
If you don't smell it....
I would take it for a nice drive at night. Then get home Open the hood with the engine running and shine a flashlight around and see if you see some smoke coming from anywhere that it could be vaporizing the leaking fluid.
 
Any more descriptive on what the chemical smell is? Chemicals all smell different.

Believe it or not, I actually had a guy describe what ended up being an exhaust leak as "chemically."
 
One thing you might try to see if it is outside the vent system or inside...run the AC on "recirc" which it will not pull in outside air, but air from the cabin (maybe take a 20 minute drive while in recirc mode). If you smell it, then it is probably something in the vent system. If not, then it might be something under the hood coming in when the AC system is pulling air in from outside (recirc off).
 
RDKC said:
Any more descriptive on what the chemical smell is? Chemicals all smell different.

Believe it or not, I actually had a guy describe what ended up being an exhaust leak as "chemically."
Click to expand...

That happens to me when I have beans.
 
Ronkh said:
That happens to me when I have beans.
Click to expand...

:lmfao

The recirc (or Max A/C depending on make) isn't a bad idea. However, I'm more worried about it being an exhaust leak or burning oil. Some of the systems he listed are signs of carbon monoxide poisoning and that is not to be taken lightly.
 
If the car was bombed to hide a smoker smell for example, that bomb cover up smell can make you sick..
I had an M5 like that and the bomb smell (which the owner didnt know about) made the owner so sick he didnt drive the M5 for a year.. Yeah, I know, had to be really bad, eh ?
It turned out the bomb was covering a ton of nicotine that was all over the Interior, and once I removed all of the nicotine from the entire car and ran some Einszett cleaner through the A/C system, the car was perfect again, and the Owner was very happy..
Good luck with this - be careful..
Dan F
 
Ronkh said:
That happens to me when I have beans.
Click to expand...

RDKC said:
:lmfao

The recirc (or Max A/C depending on make) isn't a bad idea. However, I'm more worried about it being an exhaust leak or burning oil. Some of the systems he listed are signs of carbon monoxide poisoning and that is not to be taken lightly.
Click to expand...


Problem is when the EPA gets involved for large methane release.....
 
Well I brought it back (for the third time) and they decided to use one of the cleaning products on the AC based on the idea that it was growing something on the evaporator. It didn't seem to fix the issue. Still smells like a sweet chemical after the car has been driven a few minutes and you turn on the AC or heat. Does it both on fresh air setting and recirculation. I specifically asked them to check for leaks and they say there are none. Is it possible for a coolant leak to be there but the car pass a pressure test? The AC does still work. Is it possible to flush/clean out the heater/ac box behind the dash with something inert like water, but without taking it all apart and also without damaging the electronics? If its not leaking fluid, the only thing I can think of is someone (previous owner) put some sort of de-odorizing chemical down the vents and now it like permanently smells that way.
 
The fact that you described it as sweet would really have me looking towards an anti-freeze leak. If the leak were small enough it may hold pressure for a whille. Have them leave the tester under pressure overnight and see if it holds pressure.
 
20115.0 said:
Is there any slight hazing on interior glass. That would indicate a heater core leak (antifreeze)
Click to expand...

Not that I can tell, and no wetness on the floor. The heater does heat up, but it doesn't feel very strong unless you force it to very high temps. Not sure what to make of that.
 
What you describe as a sweet chemical really sounds like a small core leak. If you turn on defrost and fan on high you will notice slight hazing on front window from air/coolant blowing on it. Any good mechanic can identify this by smell.
 
Regarding testing a coolant leak. Is there a valve between the coolant system in the engine and the heater core in the cabin that would be shut while the car is off? I ask because they typically do a pressure test with the car off and engine cold. So if the coolant doesn't even flow to the heater core until the the car is on and warmed up (and you turn on the heat) it would stand to reason that you'd never catch a leaking heater core using a typical pressure test. Or am I not thinking about this correctly?

EDIT: In answer to my own question, this car doesn't have a valve it uses a flap to acetate hot/cold air.
 
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