F430 Exhaust Rattle - Possible cure

F430 Exhaust Rattle - Possible cure

Author
Discussion

moreismore

Original Poster:

9 posts

101 months

Sunday 18th March 2018
quotequote all
Hi all, first post on here so be gentle.. hopefully this will help save a few people's hard-earned £££

So the story starts with a familiar experience, exhaust rattle, I'd noticed mine had become noisy particularly on idle and had become worse over a few months till it sounded like bag of nails in there. The noise was coming particularly from the passenger-side inner pipe but very slightly from the other side as well. Service time and the view of the dealer and a major independent was that the tips and/or the butterfly valves were gone, very common problem, and that either one side of the exhaust if not the entire system should be replaced.

When the car was off you could tap the offending pipe and it made a similar rattle noise, there are a few YouTube clips of exactly this so i didn't bother taking a video. Anyway with a bit of time (and a lot of snow) I thought I'd do some investigation.

If you're copying this you'll need to:

1. Jack the back of the car up - be careful of the bodywork as the jacking points are low and a long way inboard
2. Remove the rear wheel(s) - again be very careful of the chrome wheel nuts they chip easily
3. Remove the rear wheel-arch liners, easily done with a 10mm socket
4. Remove the diffuser, again easy with a allen key set but be careful of the black paint on the screws, I used a trolley jack (padded) to put under the panel to brace it so i could undo all the screws without stressing any or dropping it.

Once i was in there and after I'd lay under it tapping everything I could reach I realised what was actually rattling was something else.



Here's a view of the exhaust, following it along from the back box towards the tips you go past a welded section with a moving arm on it, this is the vacuum-controlled butterfly valve, further along there are brackets holding the two pipes together which look like this (sorry its sideways):




These could be moved up and down by hand causing the rattling noise. The bracket is made up of (deep breath) a joint welded to the exhaust pipe, a washer below it with a nut, a mesh-based washer which is formed around the plate that holds the two pipes together, a small pipe through the mesh, the plate, a further washer and bolt on top.

It looks like these mesh elements wear and disintegrate leaving the plate to rattle around without the correct pressure on it, here's a picture of one disassembled:





You can see here the mesh looks like a 'top hat' with the tube through the middle because the top part which sits above the plate has worn away. A working one would be fixed in place on the plate with that section.

Now the easy part, I used a solid washer which has a thickness approximately the same as the mesh, and a hole which is wider than the central pipe (so that it holds the plate, not the pipe) and put the whole assembly back together. There are four of these on each side of the exhaust, two above holding each side of the plate to the bracket and two below as you can see in the second picture. Worth checking them all.

I've started the car a few times since then and it seems to be holding perfectly, no rattle on idle and it revs without any additional noise, I did wonder if the mesh allows a little play between the two pipes but a solid washer doesn't seem to have any adverse effect.

Hope that helps!

alephnull

355 posts

174 months

Monday 19th March 2018
quotequote all
Disappointing the dealer wanted to charge $$$ for such a simple problem they either couldn't be bothered to diagnose or intentionally blew out of proportion...

mwstewart

7,554 posts

187 months

Wednesday 21st March 2018
quotequote all
Not a good idea, I'm afraid. Those are thermal expansion joints to allow the two different diameter pipes to expand and contract at different rates.

The washers that break down are made from knitted (compressed) wire mesh - it would be best to replace them with the same type.

Ferrari (surprise, surprise) only supply the complete tailpipe assembly, which is why the dealer quoted so much.