Oil Pressure? - PeachParts Mercedes-Benz Forum

longshore1 · #1 03-02-2006, 07:38 AM

I changed my oil from castrol 15W50 to Delvac 1 5W-40 and now my oil pressure gauge is acting funny. when I put the key in pre start position the gauge is already at .9 bar. could the viscosity of the oil have something to do with it or maybe the sending unit is going bad? I have a 1995 E300D

#2 03-02-2006, 07:58 AM

Quote:

Originally Posted by longshore1

I changed my oil from castrol 15W50 to Delvac 1 5W-40 and now my oil pressure gauge is acting funny. when I put the key in pre start position the gauge is already at .9 bar. could the viscosity of the oil have something to do with it or maybe the sending unit is going bad? I have a 1995 E300D

if it is going to the .9 bar with the key on engine off, it is usually the presuure sender going bad

longshore1 · #3 03-07-2006, 08:20 AM

I replaced the sending unit and now it dosent drop below 1.5 bar. I quess more oil pressure is better than none..

longshore1 · #4 03-08-2006, 10:58 AM

I changed the sending unit and my oil pressure gauge seems to be working normal at start up except is does not drop delow 1.5 bars at idle after running on the highway for a hour. could it be a clogged oil filter because of switching to synthetic? I am thinking of changing it back to 15W50 because thats what my mechanic recommededs as oil. Has anyone ever had a similar problem with oil pressure, or does it cause any damage with high oil pressure?

Hatterasguy · #5 03-08-2006, 11:07 AM

I don't see a problem 1.5 bar is well within MB spec? Actualy that seems about the average. Does it peg at 3 by 3k rpm?

Sometimes I noticed after switching from 15w50 to 5w40 that the oil pressure with the lighter oil will actualy be a bit higher. Go figure, as long as its within spec I don't care.

Put some tape over the guage!

longshore1 · #6 03-08-2006, 11:34 AM

yea it pins at 3 once i accelerate. it just dosen't drop. i am just used to it being at .5bar at idle.

Hatterasguy · #7 03-08-2006, 11:37 AM

.5bar at idle would concern me!

MB specs .3 as the lower limit but below 1 would start to concern me.

The D1 is a superior oil and probably cleaned some passages out. Also maybe the new sending unit is reading a bit differently then the old one.

Wasuchi · #8 03-08-2006, 12:30 PM

The Delvac 1 is far superior to the 15w50 for your purposes, it probably is a fairly heavy 40 when hot and the 15W50 is likely quite thin for a 50 when hot. That would explain your guage readings when hot at idle. I would be mildly concerned if my hot idle was .5 bar, mine is always around 1 bar, usually slightly higher. Sounds like the Delvac 1 is working really well to me.

longshore1 · #9 03-08-2006, 01:33 PM

thanks everyone I feel a lot better now.

Diesel Giant · #10 03-08-2006, 06:01 PM

Quote:

Originally Posted by Hatterasguy

Put some tape over the guage!

Ahhh....well that is one way to grenade an engine.

Hatterasguy · #11 03-09-2006, 10:16 AM

Well some people worry to much. Thats what my dad always says when I pay to much attention to my oil pressure guage.

"Put some tape over it and drive it" "if it blows fix it"