Weird alloy wheel centre cap deterioration

[ElAlastair]

I noticed today that one of the alloy wheel centre caps (not sure of the technical term) has been totally stripped of all colour. Here's what it looked like:

IMG_3006.jpeg (77.18 KiB) Viewed 1862 times

After wiping it down:

IMG_3007.jpeg (78.64 KiB) Viewed 1862 times

This isn't a wear and tear thing, as it was absolutely fine when I last looked, and all the other wheels (now approaching 10 years' old) are fine. It has deteriorated in a matter of days.

It's the rear wheel on the driver's side. I have no idea what could have caused it. My only thought with it being near the fuel cap is petrol, but I certainly don't recall petrol getting on it.

This happened once before, around 2 years ago, and I replaced it. It could have even been the same wheel. Last time I thought it was potentially an over-aggressive car wash, but that's definitely not the case this time.

I don't want to replace it again until I figure out what the problem is. Does anyone have any ideas?

[ciclo]

[amer6R]

hahahahaha

[ciclo]

hahahahaha

My deepest respect to all pet owners...


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[ElAlastair]

Jeez, really? I know dogs do that but I didn't know it was that strong.

Gonna be hard to stop it happening again in future...

[ciclo]

I think it is better to ignore it, there can be infinite causes of deterioration, a plastic cover cap is not a diamond and has an affordable price, removing a wheel to install it is within the reach of almost everyone.

[ciclo]

Maybe you have changed the tires recently, just the fact of removing the covers that are already years old to perform wheel balancing later can cause accelerated deterioration.

Another possible cause would be that the wheel bearing is in poor condition and the wheel center is reaching solar temperatures...🌡, but I imagine you would have noticed strange noises/hisses.

To the wheel center cover caps on my ex-Polo 9N3 happened exactly the same as yours with the same period of use. The only possible cause imaginable was either the dogs or being passionately removed/hit to be able to balance the new tires.
Everything within 'normal'...

[ciclo]

There are wheel center cap pullers to remove the caps without removing the wheel, but I can tell you that it does not work with this model of VW caps due to the relief printed on them and the curvature of the cap. I tried mine with different pullers and it was impossible, they don't give enough suction.

[ElAlastair]

I’m not going to be rushing to get another one, but I will at some point. Pretty sure it must have been a dog to happen in the space of a few days.

I did manage to change it previously pretty easily. If I recall correctly I just prised it out gently with a knife.

[SRGTD]

@ElAlastair; Some wheel cleaning products will degrade / damage wheel centre caps and the plastic wheel bolt covers. Have you changed the products you use on your wheels or have you started going to one of those hand car wash places, or if you already use the hand car wash places, have you recently started going to a different one? Those places tend to use quite harsh cleaning products to shift the dirt quickly to maximise the number of cars they’re able to clean (more cars cleaned = more money earned for them) and harsh cleaning products can strip wax / sealant protection off the car’s paintwork and damage / dull plastic trim parts. Also, some dedicated wheel cleaning products may be acid based rather than ph neutral, so can also damage centre caps and wheel bolt covers.

I see you also have one wheel bolt cover that is faded compared to the others (it’s usually the cover on the locking wheel bolt that reacts to harsh cleaning products) which might suggest a cleaning product is perhaps partially to blame for the deterioration of both the bolt cover and centre caps.

As a matter of interest, when you changed your centre caps, were the replacements genuine VW or non-OEM items from one of the many online sellers on the likes of eBay? If the latter, then it’s not unknown for the finish of some of the copies to be less durable than the OEM VW items.

[RUM4MO]

My wife has an August 2015 VW Polo 1.2TSI 110PS SEL, and so that means 5 spoke 16" alloys for Summer use, all the original centre caps on these wheels are still "like new", we swop the wheels over late October for 15" VW alloys for Winter use fitted with winter tyres, and I bought these wheels - for an earlier 6R, slightly used, from ebay Germany and so they came without tyres or centre caps. I bought what seems to be a set of genuine VW centre caps, they have the correct p/n as new items back in October 2015 - and all of them are starting to look a bit "used" due to road salt attacking them, if they end up getting much worse, I'll just attempt to buy a new set of genuine VW centre caps.

These VW parts don't cost too much, Audi ones do though, roughly £25 each if I remember correctly - even online!

[ElAlastair]

@ElAlastair; Some wheel cleaning products will degrade / damage wheel centre caps and the plastic wheel bolt covers. Have you changed the products you use on your wheels or have you started going to one of those hand car wash places, or if you already use the hand car wash places, have you recently started going to a different one? Those places tend to use quite harsh cleaning products to shift the dirt quickly to maximise the number of cars they’re able to clean (more cars cleaned = more money earned for them) and harsh cleaning products can strip wax / sealant protection off the car’s paintwork and damage / dull plastic trim parts. Also, some dedicated wheel cleaning products may be acid based rather than ph neutral, so can also damage centre caps and wheel bolt covers.

I see you also have one wheel bolt cover that is faded compared to the others (it’s usually the cover on the locking wheel bolt that reacts to harsh cleaning products) which might suggest a cleaning product is perhaps partially to blame for the deterioration of both the bolt cover and centre caps.

As a matter of interest, when you changed your centre caps, were the replacements genuine VW or non-OEM items from one of the many online sellers on the likes of eBay? If the latter, then it’s not unknown for the finish of some of the copies to be less durable than the OEM VW items.

Thanks for the info.

The first time this happened I thought it might be as you said - harsh cleaning products - but this most recent time definitely isn't that as it's been a while since I cleaned it. The bolt cover has been faded for a while and a lot more gradual; the centre cap literally went like that overnight out of the blue.

This is a genuine VW part.

My wife has an August 2015 VW Polo 1.2TSI 110PS SEL, and so that means 5 spoke 16" alloys for Summer use, all the original centre caps on these wheels are still "like new", we swop the wheels over late October for 15" VW alloys for Winter use fitted with winter tyres, and I bought these wheels - for an earlier 6R, slightly used, from ebay Germany and so they came without tyres or centre caps. I bought what seems to be a set of genuine VW centre caps, they have the correct p/n as new items back in October 2015 - and all of them are starting to look a bit "used" due to road salt attacking them, if they end up getting much worse, I'll just attempt to buy a new set of genuine VW centre caps.

These VW parts don't cost too much, Audi ones do though, roughly £25 each if I remember correctly - even online!

From memory, last time I changed one I paid around £20 when you added the shipping costs in, which is a bit steep to do it routinely for a bit of plastic. I think at the time the only place I could find one that I was sure was genuine and like-for-like was Arnold Clark parts.

If anyone has a link to somewhere cheaper and genuine that'd be great.

[RUM4MO]

Maybe just phone the parts dept of your local VW main dealership, quoting that part number, that will get a reference price, too people just jump into ebay and pay extra for no good reason.

For something "not exactly essential", once I know the dealer price, I tend just to keep an eye on that part number on ebay, typically NOS turns up within a couple of months.

I'll probably start that process after this winter, as one of the Polo's centre caps looks like its outer covering has been cut through so moisture/salt is getting in/under that outer skin.

[ciclo]

IMHO the best alternatives are:
1- Buy 1 original cover cap from an official VW dealer where you live, the guarantee of an original VW product makes it very cheap.
2- Buy 20 original cover caps for Chinese VW cars from AliExpress for the same price as 1 cover cap in official VW dealer, ...so you already have enough for 20 dogs or other "incidences" (, ❄, ⛈, ☣ ... ).

=

[ciclo]

Eg, viewtopic.php?p=603190#p603190