Greetings everyone,
Trying to isolate a rattle in the back that is noticeable when: a) turning corner; b) going over bumps. My first thought was exhaust mounting bushes but some underside photos of corrosion on exhaust system make me wonder if it is corrosion related to silencer and immediate exhaust silencer, clamps, olives, sealing rings? See photos 1 and 2. AND, just to confirm, is the circled part in photo 3 a CC? Many thanks,
Charles

 

Charles, it is any or all of the following:

• over-axle pipes hitting the cage, including the support pin at the top inside of the cage/pipe support having failed or its insulator/rubber having failed
• exhaust resonator boxes in the tunnel hitting the sides/support rubbers in the bracket failing
• under-seat main silencer boxes hitting the body

The only thing to do is to get it on a ramp and look carefully for witness marks. Essentially you need to loosen all joints from the downpipe joint backwards, and carefully align each section, do it semi tight, adjust etc etc and finally tighten. The best you can do is clear the rear calipers (if inboard brakes) by about an inch. On my car, and I have a ramp and spend time on it, I still can provoke a knock on hooilgan cornering coming out of slow RH turns at full throttle. But over normal bums etc, you can get it dead silent.

 

Dear Greg,

Thank you a million! Oddly enough, the clank, clank, clank only occurs on right-hand turns and round abouts (apart from bumps).

Just to clarify (with a diagram) . . .


a. over-axel pipes are #8 and #7 in the diagram
b. under-seat silencers are #1 and #2 in diagram
c. exhaust resonator boxes #13???

 

Yes, all correct. If you have catalysts, which I do not, then check with Bell, but I think that you will only need stainless downstream of them (ie NOT downpipes - contrary to my PM) as the cats part of the exhaust (at least on the one I had to help a mate dis-assemble) is made out of an incredibly high quality specialised steel.

 

Dear Greg,

Many thanks again. I am pretty sure my car has the catalytic converters (see photo) with heat shield.

If anyone can confirm, please do so. (directly above and behind steering rack)

Charles

 

Yes
They are the cats. You only need to renew downstream of them - until they go wrong that is!

 

Dear Greg,
Just passed HK equivalent of MOT ten days ago so I think the CCs are working ok.
Thank you for the ID and the help. Looking forward to the Bell upgrade.
Charles