Help ,I am getting oil in the water but not water in the oil.The car is also running like a dream a most upsetting state of affairs.The car has covered 134,000 miles with full MB service record and it uses only a litre of oil between 6,000 mile changes so I assume the engine is in good health.The dealer has had a look and says it is the head gasket starting to go and to leave it until it develops into an issue.Cost of doing gasket £550 ($800).I phoned an independent who said that it is fairly common for corrosion to eat away the head between oil/water channels at the back of no4 cylinder and at that mileage the head could probabley do with new valve guides and that it would be a good thing to replace the timming chain and tensioner at the same time!!!!He was very fair because he told me this was the worst case and it might not be so bad once the head was off.Cost £763 ($1100) but reducing if things did not need doing.He also said to get it done sooner rather than latter.The only sign of the problem is a slight oily feel around the top the expansion bottle and occasional light mayonnase deposit on the expansion cap,no water in oil,no loss of power or drop in gas mileage.
I feel like pushing the bloody thing off a cliff so I would greatly value your opinions about the best course of action to take.What do you think about using radiator additives in the water?
many thanks in advance
HAMISH

Your technician is correct on head gasket on this engine, very common repair. Should take about 6-7 hours & parts should be $200-300. Flushing the oil from system might require some extra time.

thankyou very much for your reply.
could you please expand on the issue of wether it is lightly that major repair work will be needed on the head eg welding,skimming etc or is it lightly to be just a straight forward gasket replacement?also your opinion on when the job should be done would be of great value eg is it like a whinning back diff that will keep going for many years or is one that goes quickly once it has started?
again many thanks
HAMISH
reply.

Unless the engine overheats a great deal the head isn't prone to warpage. Doubt from description that you will require machine work.