W126 4.2 V8 engine rattle

[420se]

Dear all

My 420SE has developed an engine rattle. This noise is present from start up and gets louder on acceleration. What problem could this be, timing chain? Cost to fix? If it's something more serious requiring an engine rebuild how much would that cost at an independent dealership in the London area. Can anyone suggest any good independents?
Cheers

 

[OlafMaxwell]

Just check first that there is not a fuel or engine management problem resulting in pinking.....sounds like nails being rattled in a tin can....and usually occurs on acceleration. Not sure which is more expensive though, know prices of ECU units. Worth going to a good independent.

 

[420se]

Thanks for the info. I don't think it is pinking as the noise is there from start up and sounds more like a rattle, the noise increases on acceleration.