What Is This? How Can I Remove It? A/C Vent Gunk/Brown Tacky Substance

[zhp43867]

So I finised up detailing a 128i today from Florida- and it came out very well overall. One thing I was not at all pleased by was the gunk on the A/C vents. This picture is all I have because I've already delivered the car. However- I offered to fix the vents if I can figure out a solution. When I searched- I found discussions of A/C smell. To be clear- this A/C does not smell!

My problem is this brownish/whitish- slightly tacky buildup which I do not believe is discoloration. I'm sorry for the poor picture- the center vents were much worse than this one (much browner).

I tried a toothbrush with APC+ (4:1), OPC full strength, Invisible Glass, Tar-X, agitation, etc. I really removed very little of the substance with all of that work.

So tell me- what is it and how do I fix it? Would a vapor steam cleaner do it? Some product I don't know about?

PS: This car has not been smoked in.

[Dan]

Make sure you test goo gone first, it can be wicked on some plastics.

[zhp43867]

Thanks for replying! Tar X should do what Goo Gone could. It has in my past experience anyway. The Tar X made it look black for several minutes- as if it absorbed- then it returned to crap color. Any other input?

It also looks MUCH worse in person. I know everyone says that- but it's very true in this case, especially on the center vents (not pictured). It looks as if you sprayed feces with an upside down C02 can- if you can image. It does look a bit better after the APC, but hardly at all.

[C. Charles Hahn]

I haven't worked on a 1-series, but by any chance does it have that rubber-like coating on it like a lot of VWs, Ferraris, etc. have? It almost sounds like it's behaving like that stuff does when it starts to fail.

Either that, or perhaps it's a smoker's car and has a lot of tar buildup?

[Ron Ketcham]

Says it's not one of my vehicles, "never been smoked in", not mine! Gotten used to that "golden patina" on everything! LOL!
Anyway, a little safe way to check out if it is a built up deposit and since not knowing what the finish is, would go with a very safe "surfactant based" cleaner like Woolite mixed and let it dwell a bit, see if the water and the Woolite breaks down what is on the surface.
Not knowing what the surface of those vents really is, this is the safest so as to not discolor the vents.
Grumpy

[C. Charles Hahn]

Says it's not one of my vehicles, "never been smoked in", not mine! Gotten used to that "golden patina" on everything! LOL!
Anyway, a little safe way to check out if it is a built up deposit and since not knowing what the finish is, would go with a very safe "surfactant based" cleaner like Woolite mixed and let it dwell a bit, see if the water and the Woolite breaks down what is on the surface.
Not knowing what the surface of those vents really is, this is the safest so as to not discolor the vents.
Grumpy

Heh.... totally missed the "has not been smoked in" part.

[Concourswanna b]

Hairspray? That would fall on any flat surface though. I'm trying to think - how do systems that have a "recirculate inside air" setting work? Would air ever enter in the vent? Probably not... who knows, but for some reason I'm thinking hairspray. Griot's Interior cleaner or adhersive remover?

[C. Charles Hahn]

Hairspray? That would fall on any flat surface though. I'm trying to think - how do systems that have a "recirculate inside air" setting work? Would air ever enter in the vent? Probably not... who knows, but for some reason I'm thinking hairspray. Griot's Interior cleaner or adhersive remover?

Those systems usually pull air in through the vents close to the floor of the vehicle (where the coolest air is.... remember heat rises).

[Concourswanna b]

Those systems usually pull air in through the vents close to the floor of the vehicle (where the coolest air is.... remember heat rises).

Makes sense.

[Ron Ketcham]

If possible, find another one of these models and take a look at the vents in it. A used vehicle if possible, and also a new one at a dealership. Compare the appearance.
May be a common concern or look that is due to the composition of the part.
At least then you'll know if it is just this vehicle or a common thing and everyone who is a professional detailer will appreciate hearing what you find.
Grumpy