Undertray PAdding
 

Hi Guys and Gals,

When trying to find a screw driver that I lost that fell through the engine bay down to the under tray, and feeling my way from the back of the undertray from underneath the car, I fortunately found the screw driver and acquired it once again. Whilst under there I felt a soft spongy object, so I thought it was something that was picked up and stuck there whilst driving, so I started pulling it out and then I realized that it is meant to do something. It is a long sponge, black about 30 cm long. I tried putting it back but saw half of it hanging down the car today so I just pulled it right out and put it in the boot. Hopefully someone here knows what it is meant to do and how to put it back properly. My guess is to dampen noise, but I suppose it could serve as redirecting air by blocking the passage towards the back of the undertray forcing air up into the engine bay. Don't know. Any thoughts?

Cheers,

John.

Taking a closer look, it looks like the radiator padding has come unstuck and worked its way to the back of the undertray. Looks exactly like the radiator foam, soft spongy black stuff.

The spongy black stuff is in fact the stuff that goes round the radiator ... make sure there is foam between bottom of radiator and the undertray or u affect cooling efficiency a lot ... also the air when driving pushes your undertray further down wich will make the thing worse.

sorry for my bad english :)

Greetings
Thomas

Thanks for help Thomas, I agree with you 100%, but how do you put it back? I have tried but no luck. Do I need some type of glue/Silicon?

Cheers,

John.

Yeah it's definitely the radiator foam. There's foam on all 4 sides of the radiator. It's there to direct air into the radiator, and to stop hot air from the engine leak around to the front of the radiator and get sucked back in through.

Get some foam and stuff it into the edges of the radiator. You have to fill the gap between the surrounding panels and the radiator.

I used Würth VKP Sealing ... i dont know if that is available in the US but its for outside use, water proof and has a strong adhesive.. works flawlessly for years in our cars.

Example:

https://eshop.wuerth.de/Dichtungsban...sku/de/DE/EUR/

You can get that also in bigger sizes...

Greetings
Thomas

I had the same thing happen with the bottom padding. Does anyone have pictures of where it goes?

Just cover the gap between the undertray and the lower radiator tank man. It's easy.

The padding that came out of mine is really thin. I can't see it covering the gap unless I put it thin side up. What if I RTV it to the radiator and to the undertray and use cable ties to close the gap permanent?

Thin side up is how it should be. User thicker foam. Don't hook the undertray to the radiator. That's the lower radiator tank right there and it's plastic. Any pressure on it and it might break. And that means new radiator.

Thanks