Idle oil pressure
 

My '83 300cdt pegs the oil press guage when cold, but drops to 20-25 psi (between 1 & 2 atu on the guage) at low idle when hot, but pegs at a little under 1,000 rpmz. I have the shop man on CD, but cant find specs for this. It has 224,000 miles on it. The local dealership is tight-liped about it.
What are specs, anyone know?? -corne-

I too do not know the actual specs but your readings are what I consider well withinin the normal range for these engines. You are allowed a lot less on hot idle before it is of any concern. Somewhere down around half of the distance between the start and the first mark on the gauge I think is still allowable.

You are normal, go have a Beer. :)

I think Diesel911 posted a picture of his eng with a gauge connected to the Oil Filter housing showing 97lbs. so if one Bar is 15lbs, that would put him at 6.46 bars. Dont remember if it was at an idle hot or cold.

The RPM`s you have the idle set will have a determining factor where your low pressure shows too.

Charlie

Question
 

Have you replaced the two rubber O-rings on the oil filter lid tube ?

If the answer is no, or not in a long time = replace them now.


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Yes; that is what I remember also.
In the Manual the Oil Pump Pressure Relief Valve is supposed to open at 110 psi. So, that would likely be the max possible Oil Pressure that someone could get.

1.5ish bar is just fine and normal for a 40wt oil at hot idle. Changine oil/viscosity can have some effect, but within a small range and really not critical.

The oil's viscosity reduces by a factor of >10x when it is hot, which is why the pressure drops. Any car of any age with a real pressure gauge (i.e. not ford or others with dummified gauges) will show similar results.

It doesnt take a lot of extra RPMs to really boost idle pressure.