Crayon/mold smell?

[coreys1127]

Hello all,

First post here!

I recently bought my first BMW. I bought an 04' Z4 as a Sunday car. I noticed when I turned on the AC and Heat is smelled HEAVY of a Moldish/Crayon smell coming from the vents.

I took my car to a local place and had them look at it. They said everything looked fine except my Air Filter hadn't been changed in about 5 years. It looked horrendous almost black with leaves, bugs etc. They changed my air filter and sent me on my way.

Now when I crank my AC I still smell the crayon smell just less. When I turn the heat on 100% of the time the heat smells like crayons. It stinks up my entire car. I'm not sure what to do? Is this a common BMW thing?

I think I remember my friends Mom's BMW growing up smelling similar.

It's not the "Leather" or car itself it's just when I turn on the Heat/AC I smell it.

Thanks,
Corey

[Steeler]

Originally Posted by coreys1127

Hello all,

First post here!

I recently bought my first BMW. I bought an 04' Z4 as a Sunday car. I noticed when I turned on the AC and Heat is smelled HEAVY of a Moldish/Crayon smell coming from the vents.

I took my car to a local place and had them look at it. They said everything looked fine except my Air Filter hadn't been changed in about 5 years. It looked horrendous almost black with leaves, bugs etc. They changed my air filter and sent me on my way.

Now when I crank my AC I still smell the crayon smell just less. When I turn the heat on 100% of the time the heat smells like crayons. It stinks up my entire car. I'm not sure what to do? Is this a common BMW thing?

I think I remember my friends Mom's BMW growing up smelling similar.

It's not the "Leather" or car itself it's just when I turn on the Heat/AC I smell it.

Thanks,
Corey

Welcome to the clan

There is a cabin filter behind the glove box that is likely the problem

Here is a link to RealOem which is a great source of info
http://www.realoem.com/bmw/enUS/show...diagId=64_1310

Here ya go

[coreys1127]

So when I took it in they had changed both the Engine AND Cabin filter. The Cabin filter is brand new. They said they didn't see any leaks or issues.

So with a new cabin filter, no leaks etc. What else could be causing that crayon smell when the heat is on?

[Steeler]

No idea, obviously something in the vents that shouldn’t be there.
Maybe try removing the cabin filter and spraying some disinfectant spray into the ducting with fan on high.

Good luck

[dc_wright]

Likely a valve cover gasket leak. Common issue on BMW I6 engines. Oil seeps out the rear corner on the passenger side and burns on the exhaust manifold. The oil smoke comes of the back edge of the hood and gets sucked into the cabin air inlet and into the cabin. Smells exactly like wax or crayon burning.

[panzrwagn]

You have mold in your ductwork. There ae two ways to fix this. Replace the ductwork (good luck with that) or get an Ozone generator from Amazon for about $70. Put the top up and start the car. Set the AC to recirculate and set the ozone generator for about 1 hour. If you do this in a garage, keep the door open, both because of the exhaust, and because ozone is very irritating to your eyes and throat. That should clear up the problem. If not, repeat the process once or twice more. This also works well for cars that have been smoked in, peed in, or left a tuna sandwich behind the seat for a couple weeks in the summer. NOTE: DO NOT GET IN THE CAR AFTER DEODORIZING IF 1) You have been smoking 2) You haven't bathed recently 3) You have bathed recently with heavily scented body wash or put on cologne. The ozone will destroy all the odor molecules, and surfaces, especially leather, fabric, and carpet will be like sponges for new odors to pick up.

[panzrwagn]

Originally Posted by dc_wright

Likely a valve cover gasket leak. Common issue on BMW I6 engines. Oil seeps out the rear corner on the passenger side and burns on the exhaust manifold. The oil smoke comes of the back edge of the hood and gets sucked into the cabin air inlet and into the cabin. Smells exactly like wax or crayon burning.

Been there, done that. When they changed the gasket they didn't completely clean up everything and the smell and smoke made me think it was an engine fire. One very complete engine detailing later, courtesy of a conversation with the shop manager, problem solved.

[coreys1127]

Okay eek.. head gasket leak or mold that's no fun.

As someone who really doesn't "know" cars is it still safe to breathe in temporarily? I'm taking it back in this upcoming Tuesday. I've got a 6 year old daughter and want to make sure first and foremost she is not breathing in something that's harmful to her.

If it is maybe if I just turn off the heater and bring a blanket for a couple days?

[StickMon]

Valve cover gasket leak, not head gasket.
Big difference.

Maybe some crumb crusher stuck crayons down the vent.
My Wife's Expedition (the "Mother Ship") is full of crayons.

[dc_wright]

Originally Posted by coreys1127

Okay eek.. head gasket leak or mold that's no fun.

As someone who really doesn't "know" cars is it still safe to breathe in temporarily? I'm taking it back in this upcoming Tuesday. I've got a 6 year old daughter and want to make sure first and foremost she is not breathing in something that's harmful to her.

If it is maybe if I just turn off the heater and bring a blanket for a couple days?

It's probably OK but you should do what you think's best. Here's some info on the health effect of motor oil. https://www.atsdr.cdc.gov/toxprofiles/tp102-c1.pdf