camshaft tick on E420

[brokebyducati]

okay - not to beat this ticking thing on our 97 E420 to death, but let me bring you all up to speed - engine is ticking on one of the lifters - performance seems to be unaffected/car runs great otherwise, all oil bridges seem to be okay (I'm told) and after two new lifters I'm told I need a new camshaft and all new lifters as the camshaft is worn and connecting with a lifter and producing the "ticktick" noise. All said and done, the bill to replace would be around $1,700 - my question is this - if this indeed is the problem, is there anything I can do (engine rx, etc.) that will help with this issue short of the complete high $$$ job? Also, what might the consequence be of not fixing this thing right away - that just seems like a lot of dollars (extended warranty company nixed helping - it's apparently a wear and tear situation) to alleviate a ticking noise -

[Ethan]

what kind of oil and viscosity are you using?

[Hatterasguy]

The only time I have heard of a M119 having a bad lifter was when the oil wasn't changed for 30k miles!

But the lifters do sometimes go bad, it could be a fluke.

[Stan Pittman]

Originally Posted by Hatterasguy

The only time I have heard of a M119 having a bad lifter was when the oil wasn't changed for 30k miles!

But the lifters do sometimes go bad, it could be a fluke.

Check the oiler tubes between the camshafts. They are known to blow the plug out and loose oil pressere to that lifter.

[donbryce]

If the E420 cam/rocker assembly is anything like the W126, look for a rocker with a gouge in the surface that the cam lobe runs on. The first 'tick' is the cam lobe chafing on the first ridge entering the gouge, the second 'tick' is the lobe hitting the second ridge of the gouge. Replacing the rocker will give you temporary relief until the worn cam lobe (the real culprit) gouges out another depression in the rocker.
I had old '75 450SE with this problem. I ended up replacing the camshafts. I actually used some emery cloth and a fine file to smooth off the offending cam lobe, which worked as a temporary fix to forestall the gouging of the new rocker. Unfortunately, the sanding/filing goes through the case hardening of the lobe and the result is even more rapid wear (but I did get a few months of no ticking).
The camshaft replacement was a complete swap from a donor engine, from a junker that I paid $300.00 for (but it had had 2 new cams installed not long before). It was a 32 hour job!
As far as damage is concerned, running with a bad rocker/cam lobe, I didn't worry too much at the time. The cam lobe is there to regulate the valve opening/closing timing and duration, so if this is disturbed, it will run rough.