SL 320 (129) M104 straight 6 - 24 valve oil pressure

[melosboy]

Hi,
Can anybody tell me what oil pressure I should expect when the car is up to full operating temperature after a long run and the engine is just ticking over. The gauge is calibrated from 0 to 3. Thanks.

 

[190]

They say it sits at 0.5 and goes to 3 on the oil gauge when you hold the revs at 3,000 but I don?t fancy my gauge sitting as low mine sits between 2 & 3 after a long run only once it went below 2 after a long run but I was using magnetic at that time so I changed back to normal GTX. And my car a 190D has done 160,000mls.

 

[Geoff_Slade]

I've got a 300D mine goes to 3 bar on starting and stays at that whilst it's under load i.e foot on the accelerator. Drops down to between to 2.0/2.5ish on tickover. My handbook also says anything above 0.5 is OK but like 190D I prefer it to be at over 2.5. Mine has got semi synthetic in it if that's any help (not sure what brand Andy Gayle changes the oil)

 

[mlc]

You have to remember that the handbook has to give you a minimum figure that would cover all possibilites.

My (1972) SL also says 0.5 bar minimum and has a scale of 0 - 3, although its actually all marked in imperial units. On all but the hotest days it never really drops from 3 around town. After a hard motorway run it will go as low as 1.5 on tick over but returns to 3 as soon as the revs rise. But this is in UK weather! I suspect that after a hard mountain climb in the south of france in mid summer things could be different - and the handbook has to cover those conditions as well.


Bottom line - in "standard" Uk conditions I would be concerned if a reading of 3 wasnt achieved whilst driving and 1.5 at tickover.

Mark.

 

[ant500sl]

A number of manufacturers have stopped putting gauges on their cars because of concerns over the varying pressures.

Using a 10w40 oil with a warm engine at idle you will usually have the gauge reading around 2. This will be the same after a long run as the oil only gets so hot. After giving the car some stick on a hot day you may see the needle drop to 1 or below at idle.

The critical factor is seeing that the reading increases to the 3 bar level when you raise the rpm. The factory publish data for testing oil pressures with a separate gauge which gives the pressures expected at different RPM.

 

[LNM]

Does the pressure drop because the oil thins out when _really_ hot? Mine is on 3 when cold but when hot and idling in drive, is just below the 1. Its done 138K