Foam Blocks

[Mr Pig]

Inside the rear of the front wings is a large block of expanded polystyrene. What's it for??

The thing that worries me is that the car my daughter just bought, a 2014 Toledo, has a similar thing but it's made of sponge instead. This strikes me as a really stupid idea as it just traps water. I had the wheel arch liner off yesterday and the sponge was sopping wet.

Anyone know what the story is with these things?

Thank you.

 

[Sjdickso]

I have also noticed this and in our older Mk4 Ibiza was recommended to take them out of the front wings. I thought the same when i have seen them as you open the doors.

Where are the rear sponges located ? or is that in the Toledo ?

 

[Mr Pig]

Where are the rear sponges located ? or is that in the Toledo ?

The sponge is in the front wings of the Toledo. The Leon has grey polystyrene in the same location.

When I squeezed the sponge in the Toledo the lower half of it was full of filthy water. The whole area was caked in mud. It seems like such a stupid idea it's hard to believe anyone signed off on it. I want to do something with it but not sure what.

 

[Sjdickso]

@Mr Pig I understand. As said same with the Ibiza Mk4 and also the Golf Mk4 block of foam in the wings and they just hold water crazy idea.

 

[Damo H]

Is it not for sound deadening/insulation?

 

[Mr Pig]

..same with the Ibiza Mk4 and also the Golf Mk4 block of foam in the wings and they just hold water crazy idea.

Yeah, but what to do about them. Just rip them out? I was thinking of taking them out, painting the inside of the wings and inner panel with underseal and putting them back.

 

[Damo H]

Yeah, but what to do about them. Just rip them out? I was thinking of taking them out, painting the inside of the wings and inner panel with underseal and putting them back.

I’d replace them and while your at it add some additional insulation too

 

[Mr Pig]

I’d replace them and while your at it add some additional insulation too

Replace them with what? What do you want to add insulation for?

 

[SRGTD]

The mk6 Golf had those foam strips so fitting them was probably a VAG thing. I don’t think they’re fitted now.

I’ve heard of a couple of reasons for fitting these foam filler strips;

• to help suppress / deaden road noise from around the front wheel arch area being transmitted up around the door / door seals. I assume that the polystyrene blocks are a revision to the original foam but is intended to serve the same purpose.
• to prevent damage to the bottom corner of the front doors during winter months in cold climates. The mk6 Golf was a heavily facelifted mk5 and the mk5 didn’t have these foam filler strips. In the mk5, water could pool on the sill at the point where the bottom of the A pillar joins the leading edge of the sill - just behind the lower trailing edge of the front wings. This water would freeze and the resultant ice formation could obstruct the door being opened. If owners didn’t notice the ice formation (they probably wouldn’t) and force was used to open the door, then damage to the bottom front corner of the door could result when it made contact with the ice. I read of cases on Golf forums at the time where owners had experienced this and the foam filler seemed to rectify the issue.

When I had my mk6 Golf, those foam filler strips were often very wet at the bottom, and the potential for corrosion did concern me. However, during nearly five years of ownership, I never had any corrosion issues. Whenever I’m parked near a mk6 Golf I have a quick look to see if they’re suffering from rust in that lower wing / sill area as a result of the wet foam, and I’ve not seen any that are, and some mk6 Golfs will now be around 11 years old now.

 

[RUM4MO]

At least these poly blocks are closed cell, the foam initially used was open cell, so it filled up with water - I see that my 2011 Audi S4 has preformed and closed foam blocks under the front wings at the mid point distance from front to back, so far they are not causing any issues ie rusting, but I do remember lots of people removing the foam blocks from that same area in Golfs and Polos, in fact maybe that was even a workshop action if you had remained within the main dealer service loop.

Edit:- actually on modern VW Group cars, that foam end piece is a closure plug, remove that and you will be able to look in and along the front wings.

 

[Seriously?]

At least these poly blocks are closed cell, the foam initially used was open cell, so it filled up with water - I see that my 2011 Audi S4 has preformed and closed foam blocks under the front wings at the mid point distance from front to back, so far they are not causing any issues ie rusting, but I do remember lots of people removing the foam blocks from that same area in Golfs and Polos, in fact maybe that was even a workshop action if you had remained within the main dealer service loop.

The foam blocks under the front wings were a well documented source of trouble on B5/B5.5 Passats; they held water and combined with road grit and slight movement of the block they caused rusting of the wing almost exactly mid point of the arch in a surprisingly short space of time. VW selectively repaired cars but only if you kicked up , even though it was a known issue.

 

[Damo H]

Replace them with what? What do you want to add insulation for?

Sorry I meant put them back in place and add additional sound deadening. @paddy6789 will be able to tell you the best stuff to buy. Imporves cabin noise etc. I only did under the boot and rear sear bench, but @paddy6789 has done a lot more to reduce cabin noise.

 

[Mr Pig]

Taking of sound deadening. You can buy stuff for roofs called flash banding. It's basically a self adhesive synthetic bitumen tape. Available in different widths and you get and adhesive promoter that goes with it. I reckon this stuff might be a cheaper alternative to the bitumen panels specifically designed for use in cars. You get a lot on a roll and it's not expensive.

 

[RUM4MO]

The foam blocks under the front wings were a well documented source of trouble on B5/B5.5 Passats; they held water and combined with road grit and slight movement of the block they caused rusting of the wing almost exactly mid point of the arch in a surprisingly short space of time. VW selectively repaired cars but only if you kicked up , even though it was a known issue.

I imported a new very late B5 Passat 4Motion - a factory order, in late May 2000, ran it until July 2013 and did not have any issues with wings rusting, a friend still owns it and it is still okay wing rust wise due to foam inserts at almost 20.5 years of age. As I said I only heard about there being issues with Polo and Golf, I don't remember seeing any mention of this in UK-PASSATS > PASSATWORLD, so some cars must have been better built than others.

Edit:- actually that car did not even have the well known issue for water coming in around the heater air inlet, though I was smart enough to work out from looking in that area, that I would have been wise to buy the improved cover from the Audi A4 B8 which is what ended up on the B8.5 Passat, and the water deflector along with ducts to protects the front callipers from "washing out".