[andl]

I have a 2018 330i. There is a horrible odor from the sunroof when you have open. The smell starts at about 40 mph. Have owned 3 bmw's with sunroof and never had this smell. The dealer has changed the lubricant and smell still exists.

[yoon_209]

something die in there?

[jeffc83]

Definitely sounds like something is rotting in there but I also recall someone saying the lube they use in there stinks...maybe it's that?

Used mine this morning (0-62mph) and didn't detect any odd smells...

[BEM-S4]

Seems like water is getting in there

[wrickem]

I had that exact same thing in both my 2014 528 and my 2016 435. I’ve never had that in any car before. They replaced the lube in both cars sunroofs and its 99.99% better. That stink just gets right in your nose.

Good luck!

[Sea-Tac]

Originally Posted by BEM-S4

Seems like water is getting in there

Even if water did get in there, wouldn't it channel out?

[BEM-S4]

Originally Posted by Sea-Tac

Even if water did get in there, wouldn't it channel out?

Not if it got under your headliner somehow and started to mildew and rot although I suspect you'd see staining now that I think about it. Maybe not though.

[Sea-Tac]

Originally Posted by BEM-S4

Not if it got under your headliner somehow and started to mildew and rot although I suspect you'd see staining now that I think about it. Maybe not though.

That's a horrid thought mildew above your head.

[vooonoo]

Originally Posted by wrickem

I had that exact same thing in both my 2014 528 and my 2016 435. I’ve never had that in any car before. They replaced the lube in both cars sunroofs and its 99.99% better. That stink just gets right in your nose.

Good luck!

makes me think wtf were they using? Truffle Butter?

[wrickem]

Originally Posted by vooonoo

makes me think wtf were they using? Truffle Butter?

You nailed it, That's EXACTLY the smell. Yuk

[pstainsb@hotmail.com]

I have a horrible smell, it's coming from the wind deflector mesh when wet, best described as a cat wee smell. After car has been sat for a while and it's been raining the mesh is always wet. And the smell seeps into the car. So run your fingers on it when open and it stinks. Spoke to the dealer and they just had no answer how to solve it, so I dry it and spray frebreeze on the mesh, this solves the problem for a while.

[bimmer456]

Must be a leak somewhere or clogged drain tubes in the moonroof rain gutter system. There should not be standing water which would cause mold and mildew. Might be more of an issue in states with more rain, snow and ice.

[AlteBMW]

Originally Posted by bimmer456

Must be a leak somewhere or clogged drain tubes in the moonroof rain gutter system. There should not be standing water which would cause mold and mildew. Might be more of an issue in states with more rain, snow and ice.

This is the most likely explanation, though the stories about the lube that is used also point to that. I recall posts some time ago about clogged sunroof drains causing all kinds of problems.
Of course, the short term approach is not to open the sunroof.

[bimmer456]

Originally Posted by AlteBMW

This is the most likely explanation, though the stories about the lube that is used also point to that. I recall posts some time ago about clogged sunroof drains causing all kinds of problems.
Of course, the short term approach is not to open the sunroof.

I though it was happening with the sunroof closed.

[WallySlash]

I think you are smelling car odor as air is drawn through the car. To explain, the sunroof when open creates a draw or vacuum of air through the car. The air picks up odor as it moves through the car. With the windows up and the climate system off open the sun roof and put your hand over the window/mirror switch panel. You will feel air against your hand. That air is being drawn in from somewhere carrying the offensive odor into the cabin. After a while the smell goes away. At least this is what I think is happening.

[jh_f30]

You could also try pulling the cabin air filter and see if it's clean. Give it a whiff to see if maybe that's the source?

[John in VA]

I recall some posts about a smell that was traced back to the lubricant used on the sunroof rails.

[5mall5nail5]

Originally Posted by WallySlash

I think you are smelling car odor as air is drawn through the car. To explain, the sunroof when open creates a draw or vacuum of air through the car. The air picks up odor as it moves through the car. With the windows up and the climate system off open the sun roof and put your hand over the window/mirror switch panel. You will feel air against your hand. That air is being drawn in from somewhere carrying the offensive odor into the cabin. After a while the smell goes away. At least this is what I think is happening.

Completely agree. When the sunroof is open air isn't blowing in, it's blowing up and over the windshield. Some air tumbles hence the deflector but it really creates a sort of Venturi effect and air is being pulled from all openings in the cabin right up past your sniffer.

[Sanko]

I have a 2016 GC and the same smell is there since it was new (and still after 3 years). I live in the dessert and technically no rain could have gotten into the mechanism or somehow under the roof. Consequently, my take is that the lube smells like pee....

[jh_f30]

This brings up a question, my car is now over 5 years old with 102k+ on the odometer. Is re-greasing the sunroof needed as maintenance at any point? Apparently, using oem might not be the most desirable.