Oil and Revs

[Beresford]

I am wondering whether someonw can help me with a question i have to do with my W124 E220TE Estate.
The car has been reving while idle similtaneously the oil gauge goes up and down also causing the car not to drive as smooth as it sometimes can.
The first time i showed this to my mechanic he said that the engine can sometime react like this after it has been inside from the cold or when electrical things have been done etc.He said it will go away.Not to worry.
The second time i showed it to him he had a closer a look at the car and noticed some fuses had been missing and or put in incorrectly.
He changed the fuses and cured the problem saying the engine was doing this because of missing or incorrect fuses.... Until
Today i have just put a new Alarm immoboliser,Car stereo in the car and it is doing the rev thing again!
Any ideas or suggestions for an English man in Scandanavia with a MB E220TE '94 Estate and a rev and oil gauge moving up and down issue, small but annoying.
Best Beresford

 

[Mikesmerc]

Oil pressure will increase when engine revs increase, perfectly normal. Sort out the rev prob and the oil pressure guage will steady up, until you rev it of course.
regards
Mike

 

[Beresford]

Any suggestions on what the rev problem could be?

Thnaks in Advance
Beresford

 

[Chazchuzzlewitt]

could be idle control valve is dirty, or air-flow sensor plate (under air-cleaner) this caused a surging idle on my old 124. Also may be a vacuum connection.

 

[Beresford]

Thanks.
I will mention this to my mechanic next time i see him.