Clicking/Ticking On Acceleration, '83 240D - Page 2 - PeachParts Mercedes-Benz Forum

JimSmith · #16 11-27-2007, 02:35 PM

I found the engine mounts in a 240D, if allowed to fail and left unattended, lets the engine rock enough to loosen the exhaust manifold, leading to a ticking noise as the engine vibrates. The ticking is increased in sound amplitude at load because the engine torque pulsations are higher and the engine motion is greater. If allowed to go unchecked the problem leads to fatigue failure of the exhaust bellows shaped tube to the EGR valve, and, in my case, the complete structural failure of the driver's side engine mount. At this point the starting evolution was visually startling. The engine would lift off the mount a few inches and slam back down with each compression stroke. In the end, this also mechanically destroyed the starter.

So, I would check the mounts if you haven't already. And, you might want to check the tightness of the fasteners at the manifold to head connection, and check the condition of the corrugated/bellows shaped tube between the EGR valve and the exhaust. Jim

tony6891 · #17 12-19-2007, 01:16 PM

I got a thumping noise coming from the rear of the tranny on my wifes 1970 280s , it only happens when taking off then it stops once the car slips into 2nd.
Does this sound like a u joint?
Appreciate any help.

Tony

P.E.Haiges · #18 12-19-2007, 01:32 PM

jkoebel,

I had a clicking sound one time in an '80 300SD. It turned out to be a bad CV joint in the rear axle. I think this is mentioned in the service manual.

P E H

Diesel911 · #19 12-19-2007, 02:30 PM

Quote:

Originally Posted by Cervan

Not quite, i had a 616 engine that ticked like crazy it would drop a cylinder at idle and then come back at about 2k rpm and it ticked the loudest when under Load.I thought it was the drivetrain turns out, that when i pulled the head one cylinder had extreme carbon build up and the rest of the cyilnders were fine. It was one injector that was nailing at high speeds, i would suggest you replace your injectors and as for the oil consumption get a compression check while the injectors are out, if one cylinder is off the charts in compression you have oil leaking past the rings also check for blow-by thats usually a good tell tale sign. Maybie it could be valve stem seals very very easy job and really does make a diffrence. of course allways look for a massive leak on the ground, thats usually where it all goes if you using that much oil you can usually see the nice blue smoke from the tailpipe by then.

Before I would do the above I would one at at time loosen the injector fuel line nuts (while the engine is running) which would cut off the fuel to the injector and see of the ticking dissapears (tighten it back up and proceed to the next injecter).
If you are not somewhere or can cheaply have the injectors pop-tested; how about swapping positions of the injectors to another position to see if the sound follows the injector change.

Stevo · #20 12-19-2007, 04:52 PM

If you can pin it down to one cylinder by stethoscope, or loosening an injector nut one at a time, swap the injectors and see if the noise "follows" the injector. I would do a compression check first however.

winmutt · #21 12-19-2007, 05:10 PM

I have a ticking sound as well that I can feel in the clutch. Vac pump is on the list of rebuilds. I hope its not oil pump or worse rod bearing. It goes away mostly when warm and switching to synthetic did wonders for it.