Mechanics

IDLE SPEED VARIES & OIL PRESSURE GAUGE NOT WORKING CORRECTLY.

1990 Mercedes Benz 260e • 235,000 miles

Dear Sir / Madam, I am a disabled pensioner from Tasmania, Australia. I own a very good 1990 W124 260E Single Wiper Model. I use Premium Unleaded 98 Octane Petrol.R
Recently a friend borrowed my baby for 2 days, I put it throught a carwash before I lent it to him, when it came back the idle speed runs at 800rpm for about 30 seconds then for no reason goes up to abour 1300rpm for a short time then drops back down, this happens all the time while driving or sitting at the lights. The other thing I noticed is the oil pressure gauge does not go to the top any longer & when sitting at lights it drops right down. Neither of these things happened before I lent it & will never lend it again. I use high octane BP Premium Unleaded 98, I specifically told him this & even wrote it down. He has put fuel in the car but he is a bit cheap 7 likely just used the cheapest fuel he could get, I am not sure though. Not having any spare money does not permit the $200 fee for the dealer just to look at it. Could you please help me.
Richard Cooke rfcooke@bigpond. Net. Au
Avatar
Ozzypensioner
January 18, 2012.



Check fuel pressure. See if the fuel filter flows freely. Check idle air control, mass air flow, and/or manifold absolute pressure sensors.

Rivermikerat
Jan 18, 2012.