oil leak on a w124 320 TE?

[Davi]

Mate has just purchased said vehicle on ebay, noted in the description is an oil leak with no further details. Just wondering if there are any 'known' problem points on this engine that could be the cause or if it's likely to be a 'general' high mileage weep.

[r129sl]

Head gaskets are a known weak point. They tend to go towards the back of the block. The replacement part is modified to prevent a recurrence. Only use Merc head gasket kit (it really is better and only pennies more expensive than an after market item) and only fill the oil to three quarters of the way up the dipstick.

[Davi]

ta muchly! Will check that out once he's taken delivery.

[bolide]

All M104 engines leak oil from the head gasket after a few years. In my experience very few engines suffer classic CHG failure where the oil & water mix or where the water is blown out of the cooling system by exhaust gases. It does happen but it's rare

Front timing chain oil leaks are common as well - check the alternator for a coating of oil. Again, common and again, not a real problem

Nick Froome

[lockhart flawse]

My E320 is doing it too. So far I have just kept the oil topped up although I will follow the tip of not filling it beyond 3/4 full on the dipstick. Otherwise the car runs like new and so I am happy to carry on topping up the oil for now but what are the first signs that something more serious might be starting to develop?

L.F.

[bolide]

lockhart flawse said:

what are the first signs that something more serious might be starting to develop?

Overheating, loss of water or loss of more oil than usual

Most of these cars don't use any oil or water between services but your car may be different. If you know the usual consumption (if any) then any deviation from that norm would be an indication

Oil leaks on these are like whining diffs - they all do it in the end but they soldier on for years and it's usually some other problem that gets them first. I think insurance companies are the mean reason for W124s disappearing

Nick Froome

Edited by bolide on Friday 8th April 23:42