Oil pressure????

[Mike Buley]

Hi,
Can someone please answer a query I have regarding oil pressure, and if mine is ok?
Starting up is a bit lumpy, but given a bit of welly the gauge goes up to 3.
Gradually if I leave it idle it drops.
When the engine is fully hot, the engine idles at just over 1.
When applying acceleration, goes to 3.
When lifting off the accelerator, but still going ahead, but losing revs it drops to 2 ish, but when I apply pressure to the pedal it goes up to 3.
Is this normal??
Also, the oil light came on yesterday, couldnt check the level correctly as I was making pretty good progress down the motorway, but there was oil in it, so I popped about half a litre in, and off I went, no problems.(no light)
Thanks folks,
Mike.

 

[Mike Buley]

Re Abbve

PS It is a 300te.....

 

[Rog_E]

Hi Mike.

Pretty much the same as I see on my 300TE!

Rarely see it drop to one, only at idle and in gear with the brakes on.

How often do you change your oil/filter?

A good grade of oil shouldn't degrade too much throughout it's service life of 6000 miles.

 

[Mike Buley]

thanks Rog,
Sounds like its about right then.
I must admit, the oil needs changing, best I do it!
Regards,
Mike.

 

[njpumphrey]

Hi, my 230e does exactly as you say, but my old 200T only dropped to 2 at idle and spent the rest of the time at max. My 240TD spends its entire time at max. Changing the oil and filter made no difference to any of them. I have no idea what this all means...

 

[jaymanek]

Hi,

Merc say that as long as it sits on 3 when under acceleration, thats fine.

First thing, have u changed oil and filter recently? if not then do so as their maybe leaks here.

From past experience, the needle may drop after a long motrway trip. If its low all the time then you may be losing pressure in the engine. Could be due to certain bearings etc.
Most of the time, it'll be fine left as it is, however this is a sign of engine wear and i would get it looked at.

Hope that helps.

 

[Mike Buley]

Thanks for the replies, appreciate it.

 

[dieselman]

Your readings of 3Bar reved and 1Bar at idle are normal. As stated the readings could go down if the oil is very hot.

If the pressure light came on whilst driving that is a bit alarming. If the level was low enough for the pickup to suck air then it would explain it otherwise either the filter or pickup strainer is blocked.
Change the oil and flush the system. You should then know where you are with it.

 

[Leylandp76]

When I did the first oilchange on my 300TE (172,000 miles) it had been dropping down low as you describe, and only going to 3 over about 2000 RPM. When I changed the oil (using Halfords' 5W-30 Synthetic) and a new filter the pressure now sits dead on 3 from about 1000 RPM. When cold it goes up to 3 immediately, and only after a long run does it drop to slightly over 2.

That is a significant improvement, so I can only assume that it had poor quality oil previously, or else was a long way overdue for a change. I recommend you change your oil and filter without delay, and use a fully synthetic oil. Nothing can shorten the life of a motor more than poor lubrication.

PS If the motor is warm and you use a jack to make sure the car is tilted slightly towards the drain plug then flushing should not be necessary. Sludge problems are more an issue if you try changing the oil when cold (bad idea).

 

[Richard Moakes]

I agree completely.

Just changed back to semi-synthetic, and now I get much better oil pressure when the engine is hot.

The previous oil was good old fashioned Castrol GTX, but it seemed to have deteriorated very badly in six thousand miles.

Good oil and good filters are cheap insurance.

Cheers,

Richard
1989 W124 300E

 

[JR]

solid 3 bar over 1800 rpm and the back to 1 bar at idle once oil is hot
this is in an engine that had a re-build only 3k ago and has Mobil 1 in it

using thicker oil will give a slightly higher pressure at idle

 

[JR]

solid 3 bar over 1800 rpm and then back to 1 bar at idle once oil is hot
this is in an engine that had a re-build only 3k ago and has Mobil 1 in it

using thicker oil will give a slightly higher pressure at idle

 

[Mike Buley]

Does the stainless sound good. I am tempted myself when the exhaust starts going.
But on an estate???