08CL63AMG

I had my car towed to a shop last month when I heard the sound on start up. A month before that they replaced valves on one side. Then this happened, they replaced valves on the other side and then found out all cams were seared when they got in there and did all the lifters too. 3 weeks after getting it back the same ticking noise came back. I didn't want to get it towed so I kept driving it (shop has had it twice in the past month AFTER I towed it and all that work was done). The ticking noise goes up with the revs as you can hear at the end of the video. The noise will go away after 15-20 minutes of driving. It happens both cold and warm starts.

Here is the video:


All work was done at the dealer and it's all been covered under extended warranty. Any ideas on what it could be? Bad lifter? Oil pressure issue? Any help would be appreciated. They've had it again for the past week after they had it for 3 1/2 weeks for the previous repair.

driveability

I would go back to them, find out who worked on the car and make sure the same guy doesn't work on it again.
I was in the repair business at a high level for 30 years, normally the guy who screwed up get's it back. You don't want him he's failed twice !!!!
Make sure the best guy gets the car, otherwise take it to another dealership and tell them the story. Be nice to them let them do their work.

principledchiro

There's no lifters used with overhead cams. There's cam followers. Ticking sounds may be produced by cam followers, timing chain tensioner, and fuel injectors. IMO, video leans me to injectors. Have the dealer replace injectors.

08CL63AMG

Thank you both for your input. Sound now only appears randomly and extremely intermittently for the first few seconds on start up but drives fine and hasn't re occurred yet. Most frustrating part of it all is since this whole thing I've had zero confidence in the car taking it on road trips which sucks since that's what it's for.

principledchiro

You know, that intermittent ticking sound may be a very small exhaust manifold leak. Audible when cold, then disappears when warm...from expansion.

GMBALL

I have been experiencing this noise for more than 2 years. It is normal for these engines. You have to start worrying about it only if that noise does not dissappear after 5 minutes of driving.

Don't worry about it, mine does exactly the same thing, too.