95 s500 oil pressure drops below 1 bar when AC is on and a little above 1 bar when idleing with Ac off. Goes up to 3 bars when driving. Also get a ticking noise at idle. Other than the oil tubes blowing out can they also get clogged? What should I check for?

REPLACE ALL THE OIL TUBES FIRST. IF THERE AREN'T ANY BAD ONES, I WOULD LOOK AT THE OIL PRESSURE RELIEF VALVE.

trintrick,

I am pretty sure your oil pressure gage readings are normal for a fully warmed up car. I know the German manual for the W123 Diesels says 0.3 bar at idle with the car fully warmed up is ok, provided the meter pegs when the engine is under load. All my cars, except my 190E 2.3-16 go below 2 bar when idling fully warmed up. The 190E 2.3-16 always stays pegged at 3 with the engine running. But that is the only car I have seen that never drops off the peg when warmed up. Sounds like your idle lowers slightly when your A/C unit comes on.

Good luck, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Thanks for the information!

on the other hand - how long has it been since an oil and filter change. I have noticed that over a period of time the oil pressure will drop slightly based on how long it has been in there.

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Jim

I agree; your readings are perfectly normal -- check your owner's manual.

On the other hand, I got tired of looking at readings of 0.5 bar at idle, in drive, in summer. Since I switched to Mobil 1 15W-50, never gets below 1 bar.

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Steve
'93 400E

Had the same problem, checked with MB shop they said levels were normal. Changed oil and put in Redline and the levels are higher now. Does not go below 1 bar.

Also it might not be a bad idea to check that little used obscure book in the compartment where you probably don't keep your gloves to be sure you are using oil of the correct viscosity for the season and climate.

Peter

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