Bought this CLK 430 cab new in 03. Barely has 10k miles, has had one service at MB store. Ever since new, it has had a substantial amount of valvetrain noise. I didn't realize exactly how noisy unitl I bought a used S430 a couple of weeks ago. When I realized how quiet and smooth the other car was, it put me back on this subject again. Problem is, how do I approach my delaer/tech about the noise? I'm sure they're going to want to get rid of me, but short of pulling up next to another similar car/motor, how do we quantify? What's the criteria for a lifter job? Wasn't this a fairly common problem in the 210 430? Main thing is, I just don't think the car performs as well as it should. It doens' thave as much power or get as good fuel economy as my last two 430's. In fact, this S class gets far better gas mileage and weighs probably 500 pounds more. On top of that, I'm a clean freak who's not too happy about my car sitting at the service department for a couple weeks getting greased and scratched all over. I think perhaps if I could get this issue recitified, I'd probably just be on my merry way. Techs/SA's at factory stores, how can I approach this without making an enemy or getting reputation as a pain in the backside?

Most dealers are very aware of this problem and would gladly replace all your valve lifters if you just complain about them. Especially since it is an easy high paying job.

that's the type info that I'm looking for. I just wanted to know if I was going to be out there on my own. If I've got some ammo, then I feel better. Seen a TSB on this?

I see several of these complaints every month. Most of the time the noisy lifter(s) can be easily located. They should replace them all, though. Ask them to inspect the camshafts carefully. If they find evidence of "chatter" marks they should replace the camshafts, rocker arms, and lifters. None of this should be a surprise to your Service Dept. I've also found carbon fouling of the pistons to cause complaints of engine noise, usually following a cold-start. This noise can be mistaken for lifters to the untrained ear. The way I repair this is simple. While the valve covers are off to inspect the valve train, I remove one spark plug from each cylinder and pour GM Top Engine Cleaner directly onto the pistons. The longer you let it sit the better, preferably overnight. Before the plugs are re-installed I crank the engine over to remove the cleaner. After the initial road test I change the oil and filter. If you don't want to use the GM cleaner, Techron works well also, just not as quickly. I hope this helps.