W124 Cabrio - Engine 'whirring sound' when revved

[AdrianK]

I've owned a 1994 W124 Cabriolet for 10 years which has 136,000m and a FSH.

All is generally well and it has never let me down, but the engine seems to be getting progressively more noisy over the years. There is a general noise best described as a 'whirring' which is engine related (when revved, not driven). It has been there for a while now, but more noticeable as she gets a bit older.
It also seems to have lost some power and struggles up hills these days.

Secondly, it also revs up and down for a minute or two when first starting before it settles into normal running. I doubt these two things are related though.

Any advice on what likely to need to be sorted would be appreciated.

Thanks in advance.

 

[AdrianK]

Bump!

 

[AdrianK]

This is it

 

[alabbasi]

Whirring sound could be a locked up fan clutch that's always engaged. Hunting idle and power issue may be electrical as this car was built in the era of the biodegradable wiring harness. Or it could be ignition or fuel related. A good MB specialist will be able to inspect and diagnose.

 

[ManofKent]

Could just be low oil in your power steering. Mine made a rpm related whirr when I had a leak and oil got low.

John

 

[AdrianK]

Thanks for the feedback and gives me a few options to investigate. Appreciated