I have this really annoying problem which seems to be exhaust related.

If I go through puddles or deep water it seems like the exhaust is vibrating against the heat shield between the exhaust and the propshaft. Had a look underneath but everything seems solid.

Hopefully when I fit the Blue Flame exhaust it will cure the problem but as that wont be for a wee while yet I need to cure this. Anybody got any ideas? It definitely has something to do with the amount of water passing underneath as when I fitted front mudflaps the problem lessened but obviously with all the wet weather at the moment its doing my head in.

Might seem like a stupid question but is the heat shield really necessary?

Hoping you can help.

Cheers,

Steve

If its a 4x4 and only happens when the exhaust is warm/hot and hits cold water then I was told it was a not unknown but uncommon problem on all cars on the 4x4 chassis (TT's etc). The dealer fitted a new centre section and realigned it and all was well. Pretty worrying the first time it did it - in a monsoon outside Edinburgh - thought the bottom had fell off the car!

Steve, I would put up with it for now. The heat shield does serve a purpose

and the rain will stop soon (I hope)

Thanks Musky, was the centre section a modified part from Skoda to correct this problem or just a case of re-alignment?

Steve

Steve, I would put up with it for now. The heat shield does serve a purpose

and the rain will stop soon (I hope)

Yep, problem is in Scotland it tends to rain quite a lot rather regularly! Although admittedly you seem to have more than your fair share at the moment:eek:

Steve

I have a feeling I have the same problem. When the car recently went into Jabbasport they said the centre section is slightly out of line where it has been joined with the back box and now is hitting the heatshield. I couldn't see it until I had a ran my hand along the pipe section to see how close it was to the shield. The center section mountings have broken due to the position it has been fitted in so will have to get a new one. The noise is noticeably worse in the wet but also vibrates when i take a left hande bend which is quite annoying!

Driving over the A939 **** Bridge (no doubt to be deleted by the swear filter) to Tomintoul road one MAY day I had to run through a foot of snow. When it packed round the exhaust I thought I'd totally fecked it! :eek::eek:

The centre section according to the garage was hitting the floor, not the heat shield, due to twisting when hot then suddenly cooling part of it. They replaced it and moved it but as far as I know it was a standard one. It cured the problem but it has done it since - after the clutch was replaced - but only once. There is no noise whatsever under normal or even slightly wet conditions - it has to be a monsoon or snow.

I dont want to disapoint you but mine did it with the Blue flame as well, I put it down to sudden cooling of something as the water hit it but as it only happened a few times (its usually drier down south) I didnt bother to investigate further

Cheers Stuart, A mate who prepares rally cars reckons if I wrap the exhaust with performance exhaust lagging it will allow it to maintain a fairly regular temperature without rapid cooling. Will see how it goes. By the way do I definitely need the 100 cell cat to get the exhaust to fit or could it fit to standard and change the cat later? Or as I suspect is the bore too large for this?

Regards,

Steve

Cheers Stuart, A mate who prepares rally cars reckons if I wrap the exhaust with performance exhaust lagging it will allow it to maintain a fairly regular temperature without rapid cooling. Will see how it goes. By the way do I definitely need the 100 cell cat to get the exhaust to fit or could it fit to standard and change the cat later? Or as I suspect is the bore too large for this?

Regards,

Steve

The 2 wont be interchangeable, also dont chuck the old system as the cats cost a fortune for the 4x4 so in a few years when peoples start to fail it will be worth something, I know you scots dont like to see money disapearing !!

I have this problem too - a vibrating / thumping under the floor when I go through a big puddle (or snow). What would be the consequence of ignoring it? Will it make it worse or just annoy me a bit?

it is only an irritation in practice - it's amazing how much the exhaust system can change shape when suddenly cooled in one place. Look under there in normal conditions and it is likely to be hard to understand how it can move far enough to knock.

my 4x4 also had a fit in monsoon rain back in July, vibration under the car was terrible, but gradually eased off. Thought the car was dying on me at the time. Found some discussion of this on a Golf R32 forum, and the idea of 4x4-specific issues with the exhaust seems a common theory.

Have just had a custom Hayward and Scott installation to replace the exhaust pre-remap, and the pipe work is now well clear. May have to wait a while though for another monsoon to test it, fortunately there are other benefits of the new exhaust I can enjoy every day.

Adam.

my 4x4 also had a fit in monsoon rain back in July, vibration under the car was terrible, but gradually eased off. Thought the car was dying on me at the time. Found some discussion of this on a Golf R32 forum, and the idea of 4x4-specific issues with the exhaust seems a common theory.

Have just had a custom Hayward and Scott installation to replace the exhaust pre-remap, and the pipe work is now well clear. May have to wait a while though for another monsoon to test it, fortunately there are other benefits of the new exhaust I can enjoy every day.

Adam.

Ive had a blue flame & Milltec Custom Exhausts on the 4x4, Ok bigger bore but both did/do it :(

I wonder if lowered cars are at more risk. My 4x4 was fine on original high suspension, think this summer was the first very heavy rain I'd driven in since switching to KWs. Car is not at its lowest setting, but fairly close. Mind you, this summer's rain must be some of the heaviest since I bought the car 4 years ago, so who knows.

Adam.