Cam Replacement

[Kodiak]

How difficult is it to replace a cam in a 190E 2.3? What I am really asking is how do you know when the rockers are adjusted properly. I plan on purchasing the cd soon. Does it give you this kind of info? Also, what are the other parts that I should replace if I do the Cam?

Thanks for everyone's input

[Gilly]

If the cam is worn or damaged, you may need to replace the cam followers (rocker arms). You just need to inspect them and see, it is case by case. Yes you will need to check the hydraulic compensators, they perform the same function as a "lifter" on a push-rod engine. To do this you need a special tool and a dial indicator. You may want to condider replacing the valve stem seals when you do the camshaft. I believe the work info is all on the disc. I have a complete set of discs. If you want I could look for you and find out. The dial indicator you could get at anyplace, probably even Sears in the tool dept. The fixture you need is maybe 100 bucks or more from MB, I don't know any way around buying it. Maybe the local MB dealership will let you use theirs? I doubt it, doesn't hurt to ask.....Gilly

[Benzmac]

Also, the timing chain adjuster will have to be removed and reset. It is a ratcheting type... You will need to properly torque the rocker carriers too or the cam will go snap.

[Gilly]

Yes, the timing chain tensioner will be part of the job, a torque wrench certainly will be a required tool, I kinda skipped over the basic stuff. On the rocker carriers, or bearing brackets as Ma Benz calls them, you certainly will want to torque them properly (21nm, I believe is the "latest spec"), but since the head is the lower half of the cam bearing and the bearing bracket is the upper half, I don't believe that under NORMAL circumstances breaking the cam is a real hazard....Gilly

[ejsharp]

Are you sure you want to adjust the rockers? Normally you adjust the valves. The rocker arm is fixed.

Smiles.

[Gilly]

Earl: On most any "modern" car, when saying you are "adjusting valves" what you are really doing is adjusting the valve lash, this is the function of the rocker arms, however. But when you are adjusting valves, one assumes you have a "solid lifter" in reference to a pushrod engine, or on a o'head cam engine that you don't have hydraulic or automatic valve adjustment. On the engine in question, the 102/103 MB engine, the rockers do have hydraulic adjustment, or hydraulic compensators as MB calls them. They don't need adjustment after being properly installed, but what is being discussed is the initial set up of the clearance of the compensators.......Gilly

[ejsharp]

So that's why I never had to adjust the valves on cars that I've owned that had hydrolic lifters! I just this week adjusted the valves on my wife's 1984 318 BMW. It never dawned on me that the 318 must have solid lifters.

Smiles.

[Gilly]

EEwwww!!! Well, I didn't really want to get into a discussion on BMW's, still trying to forget!!! Yeah, I believe a 84 318i would be mechanical, as would the 320 and 325. The term "lifter" is more associated with a pushrod engine. On a O'head cam engine, it would be more appropriate to use the term "mechanically adjusted" or "Auomatically or hydraulically adjusted" valves, but again, it is the valve gear or mechanism that is being adjusted, not really the valves themselves....Gilly

[ejsharp]

Wow... never thought of that before. Overhead cams do not have pushrods! I think the fact that I cut my teeth on Ford flat heads shows!

Smiles.

[Gilly]

Yes, it is hard to get used to, I know it was for me after my first 8 or so years working for the same dealership in the Buick shop, then switching to Mercedes. Still catch myself talking about the "hydraulic lift......er I mean hydraulic compensators" when discussing valve train problems. It is a treat to get away from timing belts, though, not that it was a BIG problem in the Buick shop, we had a few, though. Still kind of a GM loyal guy. The front wheel drive cars are hard to beat in Wisconsin in the winter......Gilly