Why is my SL exhaust humming?

[koksy]

I have a 1975 350 SL and I had the exhaust centre section and tail pipe replaced at Kwik Fit... I know I know but it was MUCH cheaper than anywhere else! Anyway, we are now on exhaust number 3... each time they fit a new exhaust, there is a high pitched humming noise around 3250RPM. I take it in, they fit a new one, humming noise still there. This humming noise wasn't there before Kwik Fit got their hands on it. Just had it MOT'd and serviced and they were sure it was the exhaust too but they can't understand why when it's brand new. Anyway, before I contact head office, is there anything else that may be making this high pitched hum (as I said only around 3250RPM) or anything that I could get Kwik Fit to check with the fitting? I simply can't beleive that I could be unlucky enough to get 3 faulty exhausts!

 

[shadowninja]

could be a new design or use of materials causing the sympathetic(?) vibration... only option would be to get a custom job done.

 

[Mr Teddy Bear]

There's Nothing Quicker Than A Kwik Fit Fitter.....

at f**king things up!!!
'The quality will be remembered long after the price has been forgotten.' Has a lot of truth in it.
If you bound by a tight budget try Dronsfield they claim to be the largest nonfranchised merc parts dealer/servicer and I think they may do second hand stuff too....
Otherwise there's always Euro or GSF. I would fit something else and throw the Quick F*** one back at them. 3 strikes and your out in my book..

Mr Bear.

 

[shadowninja]

Quick F***

:mrgreen: :twisted:

better than "halfwits" for Halfords.

 

[Blobcat]

Because your cam is on song and it doesn't know the words??







I'll get my coat..

 

[Parrot of Doom]

The solution is never to go to Kwik Fit again, except to have them remove your exhaust and refund you your money. At which point you go to the nearest Mercedes dealer/indie, and order a proper one. And if you can't do that, get a stainless steel one made up by someone who knows what they're doing.

 

[iamamanc]

I priced a back box from a few places tried MB and it was a touch cheaper than most of the others BUT it was a MB quality part - thicker grade, better welds so it should last twice as long as a bean tin from Quackfit.

EG Quackfit ca £140 fitted - MB £98 and I fit it myself - 2 bolts and a hook

PS it's probably humming cos it's so happy that it's such a lovely classic car
Nice one