The car has done 123000 miles and up until I owned it full MB service history. Looking at the maintenance record it has had either fully synthetic or semi-synthetic oil at every change. Just over a year ago I replaced the camshaft and all the followers because the original was badly worn the difference in power, smoothness and sound was substantial. I replaced the valve stem seals about a month ago and found in the process, to my amazement some pitting already on the cam lobes. Fortunatly it was replaced under warranty. The oil pressure is good and there were no blockages in the cam oil spray bar would this occur normally even with a good service history? <BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by LarryBible:
Sorry to say so, but my money is on the valve guides. This sounds like a worn out engine. I don't remember how many miles you said are on it, but mileage is not necessarily the right barometer. Do you know anything about how the engine has been driven and maintained?
Sorry to be the bearer of bad news, but I think it's valve job time. It would be interesting to do a compression check, then squirt in the cylinder before rechecking compression and see if the compression comes up, if it does, you might get by with a valve job which includes fresh guides.