Horrid clicking sound - W210 :(

[kiwifraser]

Our 1999 E240 Estate (W210) has a really loud clicking/ ticking noise when coming from the engine somewhere. It is similar in sound to a really badly set tappet. It is worst at cold startup, and everything is warmed up it quitens down. It can then come and go intermittantly, but does seem to disappear if driven hard for a while. My first thought was a sticking hydraulic lifter, but don't know if it even has these.

We ran the car on Vixpy's dyno, and although it was fuelling correctly on power runs, it was significantly down on power at circa 130HP instead of 170HP. The lambda may be faulty and the mixture was out at idle, but I have yet to find someone to run the fault codes for me. There have been no warning lights on the dash in the last few weeks, however prior to that it flashed up 'Oil sensor defective' a number of times.

Any ideas what the noise might be???

[mt10argyll]

Just a thought it may be the exhaust manifold I had
a loud ticking on my TVR sounded like badly adjusted
tappets but turned out to be a crack in the manifold
worth a check

[marc.l]

sounds like an injector blowing around the seat if its an oil burner.

edit to say never noticed you said what model it is, not sure if it applies to petrols or not.

Edited by marc.l on Thursday 19th March 15:10

[kiwifraser]

It's an E240 petrol. Sounds very mechanical, and the sound is directly linked to engine revs.

Edited by kiwifraser on Thursday 19th March 15:41

[GregE240]

Hi

My old E240 (hence my login name) had exactly the same symptom as you describe.

It was indeed a hydraulic lifter, it was especially bad when cold, but soon disappeared. I learned to live with it.

[mr spectraflair]

Sounds Tappety? What engine oil are you using?
Mine suffered this prior to changing to 'Mobile 1' which cured the noise after a few runs... It's been faultless since.