Say it isn't so... I have been running Mobil 1 0w40 in the 95 E320 wagon for a year and a half with no problems. Now when warm, it is dropping below 1 bar oil pressure at idle when it is in gear (slightly less than 500 rpm on the tach). In park at idle (slightly above 500 rpm) it hovers around 1 bar. It used to stay around 2 bar at idle. The pressure does peg at 3 bar when driving.

I am at a loss as to what to check or do. There isn't any oil in the coolant or vice versa. Do the senders and/or gauges go bad? Do the oil pumps ever go bad? Would the bearing clearances open up seemingly overnight so it won't hold pressure at low rpm? Should I just change it to heavy dino oil and see what happens? I like this old wagon and would really like to keep it on the road.

Thanks for the help and advice.

Tim Benner
Dayton, Ohio

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

I'd start by changing oil and filter. Pressure sender could be going bad, would probably be my next swap, or check pressure mechanically.

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Gone to the dark side

- Jeff

Thanks for the idea!... Feeling a little more optomistic now. No change in the oil pressure after the oil change. I'll replace the sender and see what happens.

Tim

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

Your oil pressure is perfectly normal, ideal actually, no reason to do anything except stop worrying about it.

I thought that 2 bar at idle was OK and anything below 1 bar was big trouble. But why did it change? Maybe the new sender would be a good idea anyway just for the warm fuzzy feeling it provides.

Thanks,

Tim

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Tim Benner

00 ML320 170K
95 E320 wgn 160K

Check your owner's manual. It's fine to be under 1 bar at idle.

for my 190e 2.6 i also remembered my pressure to be at 3 while driving and around 1 when hot and sitting. After a while it started to stay at 2 while driving and never reaching 3 and went almost to 0 while in idle. I changed my oil, thinking the filter was plugged and voila. Now back at 3 and 1.

BTW i use synthetic also, so the sensor is reading it right.