surface corrosion in cavity under spare wheel well

[Dark_cze]

just a little notice to anybody planning to keep his car. There is little cavity (about 50x4cm) under spare wheel well. Yesterday I had car lifted on stand and noticed a little bit of surface corrosion inside of this cavity. There are 3 holes and nothing is really blocking it. Iam gonna guess water and dirt will get inside and get stuck there. (It is older photo)

[SRGTD]

Is it possible that it might be wax that was injected into the cavity when the car was built to protect against corrosion rather than surface rust?

I’ve used DIY rustproofing products many years ago when corrosion protection applied to new cars was pretty much non existent. This products were essentially a protective wax for spraying the floor pan, under wheel arches and into closed box sections and cavities, and were yellowish - light brown in colour and perhaps might have given the appearance of surface corrosion, when they were actually providing a protective layer.

If it is surface corrosion, then it’s very disappointing to have occurred in such a short space of time, especially on part of the underside of the car that isn’t being directly bombarded by dirt and road spray thrown up by the car wheels. If it is corrosion, then it might be worth raising it with your dealer to note on their system in case it worsens, although whether or not you do this might depend on how long you’re planning on keeping your car.

[ho8882000]

just a little notice to anybody planning to keep his car. There is little cavity (about 50x4cm) under spare wheel well. Yesterday I had car lifted on stand and noticed a little bit of surface corrosion inside of this cavity. There are 3 holes and nothing is really blocking it. Iam gonna guess water and dirt will get inside and get stuck there. (It is older photo)

Hello Dark_cze,

Thanks for sharing this information, I am planning to keep my Polo for a long time. I will definitely keep an eye on this.

Thanks.

[Dark_cze]

I have some wax or something like that drips on bottom of front rails and it is light yellow this was little spots in brown colour (not found anywhere else on the car) around 2-4mm in diameter. I don't think it is mayor problem it will most probably take years to go through. I noticed in in spring 2020 and it didn't get any worser but I used quiet a bit of DIY sealant for car cavities (brown in colour) inside so I will report again in spring. I forgot to take a photo while I was there. Also I was kinda suprised front wheel arches are open at lowest point and they were mostly clear. There was a bit of dirt but I didn't feel any need to clean it so I left is as it is. Most parts is shared between gti and cheapest polo variant so it not that bad for quiet cheap car after 2 years and 2 winters.

[ho8882000]

I have some wax or something like that drips on bottom of front rails and it is light yellow this was little spots in brown colour (not found anywhere else on the car) around 2-4mm in diameter. I don't think it is mayor problem it will most probably take years to go through. I noticed in in spring 2020 and it didn't get any worser but I used quiet a bit of DIY sealant for car cavities (brown in colour) inside so I will report again in spring. I forgot to take a photo while I was there. Also I was kinda suprised front wheel arches are open at lowest point and they were mostly clear. There was a bit of dirt but I didn't feel any need to clean it so I left is as it is. Most parts is shared between gti and cheapest polo variant so it not that bad for quiet cheap car after 2 years and 2 winters.

Thanks for sharing the information.

When you have a chance to lift up your Polo again, can you please take some photos and post it on the forum.

I would like to know more about this potential problem.

Thanks.

[Dark_cze]

I will but it will be around february/march 2021 when I will be changing wheels again

[ho8882000]

I will but it will be around february/march 2021 when I will be changing wheels again

Thanks.