gushoggblake
New Member
I've been trying to track down where NVH is coming from in my E280 and have realised one element of it is the engine. It's a very low regular thrumming which I assume is from the tailpipe.
It used to idle silently but has had various engine issues since I changed the head gasket (and the head, with a used one from an R129, as the original was too corroded). I don't do much mechanical work and only have a basic understanding of things, so my mechanic has mostly been sorting these issues - primarily rough idle, which is now cured.
Another known issue is that the timing is off (retarded) by 5 degrees, but since this will have been the case before the head work I think it can be ruled out as the cause of the rumbling.
Could an engine issue cause this (something like misfiring messing with the timing of sound waves that the muffler is designed to deal with), or is it more likely to be an exhaust component? Any relatively easy tests I can do before taking it to a mechanic?
More details:
- Engine idles well at 600rpm and seems generally healthy, possibly slightly lacking in power, fuel economy OK
- There is sometimes a vibration/rattling from the back of the car; this has been particularly bad after a long drive
- I've just finished putting Kilmat sound deadening panels on the roof and sunroof as I thought all the flat metal areas might be resonating, but it hasn't made much difference to the exhaust related noise
It used to idle silently but has had various engine issues since I changed the head gasket (and the head, with a used one from an R129, as the original was too corroded). I don't do much mechanical work and only have a basic understanding of things, so my mechanic has mostly been sorting these issues - primarily rough idle, which is now cured.
Another known issue is that the timing is off (retarded) by 5 degrees, but since this will have been the case before the head work I think it can be ruled out as the cause of the rumbling.
Could an engine issue cause this (something like misfiring messing with the timing of sound waves that the muffler is designed to deal with), or is it more likely to be an exhaust component? Any relatively easy tests I can do before taking it to a mechanic?
More details:
- Engine idles well at 600rpm and seems generally healthy, possibly slightly lacking in power, fuel economy OK
- There is sometimes a vibration/rattling from the back of the car; this has been particularly bad after a long drive
- I've just finished putting Kilmat sound deadening panels on the roof and sunroof as I thought all the flat metal areas might be resonating, but it hasn't made much difference to the exhaust related noise
