failing oilpump M113K? Weird ticking from oilpump

[renscls55]

Hi there folks,

I recently became the proud owner of a CLS55 AMG 05'. The car has now 49000 miles and comes from the first owner. (She was 61 when she bought the car new in 2005). The car has always been serviced by a Mercedes dealer.

However, I notice a present rattle from the oil pump. This sound irritates me greatly and want this noise as soon as possible to go away. The ticking seems to be gone above 3k rpm. The subject has been mentioned before on this forum. But I would like to ask you as experts if it is definitely the oil pump and if it can be replaced without taking the subframe etc. down.

Thanks
Rens

 

[Petrol Pete]

Hello and welcome. If this car has a full MB service history the fault is unlikely to be the oil pump , this car has an M113 engine which is widely regarded as the most robust petrol engine MB ever produced . There have been failures due to a £2 'o' ring failing on the oil pick up pipe but it is very rare . My own car with a M113 engine has almost 150K miles on it with just a regular service history of normal oil changes.

The chain that drives the oil pump can stretch and the chain contacts a part of an aluminium casting , the chain simply wears a groove in the casting and does not fail completely . Again, very rare on an engine with 49K miles with full service history.

I don't know if your engine has a saddle sump (some M113 do, some do not) but with a saddle sump you have to drop the steering rack and the sub frame to remove the sump. I suspect it's the same even with a plain sump.

Unfortunately there is no indication of engine oil pressure and it is not being monitored by any system in the car . The first inkling you get with an M113 engine of this vintage of low oil pressure is when the engine is destroyed by low oil pressure.

There is an oil pressure test take off point that is blanked off , an adapter can be screwed in and a hand held oil pressure gauge attached to read actual oil pressure.

Have you checked everything that is being driven by the serpentine auxiliary belt ? It is very easy to pop the belt off ang give the idlers/ac pump/water pump/ alternator etc a good spin to check for any bearing play.

If it were my car I would do all of the above before dropping the sump . If you are concerned about oil pressure get that checked first and proceed from there.

I am not the one of the 'experts' you were expecting to contact on here , but there are real experts here and they will be along soon to help even further

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Not a 'K' engine but M113 oil pressure take off point circled in red.