Guys,

I have a 2000 E430 with 105k miles. Right after a 2300 mile trip last week a new noise developed that sounds like a rotating component is off center(guess)..bearing wear(guess). It also sounds like it's coming from the left side valve train or right below. The noise goes away after driving for approximately one minute. I have not let it idle without driving to see if the noise goes away.

Question 1: Common issue? I know there is some complex valving in the hydraulic lifter system....could a passage way be blocked and not getting oil immediately?

Question 2: Could running a 1/2 to full quart of transmission fluid help clean the valve train? Will it harm the engine in any way?

Just looking for some initial suggestions/guidance/experience.......I'll thank Stuart in advance and can someone buy this guy a beer? I'm in the US...otherwise I would!

Thanks, Matt

 

probably a lifter....also, carbon build-up on the piston also causes a similar noise and messes up a lot of people trying to diagnose that noise!
I have also had to replace camshafts and or rocker arms and rocker arm shafts in extreme cases