I have a 78 300 SD with 121 K miles. I hear a constant tapping coming from the engine. The tapping is not as noticeable at idle, but increases and becomes lounder as the RPM's increase...I just purchased the car a few weeks ago, the previous owner had it sitting in a garage for about 8 years...I had the oil changed hoping this would help cure the tapping...no luck...Could a valve adjustment eliminate the noise? Or do you think its a collapsed lifter? Any thoughts on the cost of repairs?

P.S. I find this forum to be an incredible wealth of information...Thank you, Juan G.

I'm no expert but it sounds like you have a stuck valve. If the engine has sat for 8 years without running or very little use a valve could stick. Fix quick or you will toast the valve.

------------------
82 300SD 100K
91 Caprice SS
92 Jetta TD

Hi

Well, these car's valves have to be manually adjusted, so I would start with that. They should be done every 10000 miles or so.

Good luck with the car.

Nicolas

------------------
1982 300D - http://members.xoom.com/nicodore/

Have someone check the camshaft. The early 300SDs did have a problem with cam wear. The updated camshaft requires installing different rockers(with hardened inserts) and valve springs(with a yellow paint marking)to support the added weight of the updated rockers. If you pull the valve cover, look for wear on the tips of the cam lobes. And while you're in there, see if the valve springs have a yellow mark on a couple of the coils of each spring.


------------------
W.R.Durrance
ASE Master Tech
Mercedes Tech 19 Years