UK-POLOS.NET - THE VW Polo Forum

Hi everyone, greetings from Italy!

I keep noticing a white/cream-colored substance oozing from the edge of my rear right wheel arch (see attached photos). It's not the first time I've seen it — it seems to come back even after cleaning it off. It has a thick, almost paste-like texture when dry.

I bought the car brand new (km0) from an official dealership back in 2018, and this area has never been involved in any accident or bodywork repair as far as I know. So I'm a bit puzzled about what this substance could be and why it's forming there.

Does anyone recognize this? Could it be some kind of factory sealant, cavity wax, or sound-deadening material that's degrading over time? Should I be worried about moisture getting trapped or early rust starting underneath?

Any input appreciated, thanks!

I have no idea what it might be and have never had anything like that on any VW - or any non-VW - that I’ve owned. Has it done it since the car was new or has it only recently started? Is odourless? I don’t think it’s cavity wax as I don’t think there are any cavities in that area that might have been wax injected. Also, any seam sealant that might have been applied in that area should be firm (with a degree of flexibility), especially on an 8 year old car unless it’s come into contact with another substance and reacted adversely with it, possibly causing it to become soft / semi-liquid.

If it was my car, I’d loosen off the textile wheel arch liner and have a look behind the liner to see if that gives any clues as to what it might be.