Hello!
I recently purchased a manual 1981 Mercedes w123 200D, 322.000Km (200.000 miles) in Spain in almost perfect condition, but the car has one issue, it has 0.3 bar oil pressure at idle.
However, when I push the pedal I get to 3 bar when I reach around 2.000RPM.
What could be causing the issue? I have heard about an open oil pressure relieve valve and worn bearings but it is weird to only get low oil pressure while at idle.
Help please! 🙂 /p>
What could be causing the issue? I have heard about an open oil pressure relieve valve and worn bearings but it is weird to only get low oil pressure while at idle.
It's not weird at all, idle is when the oil pump is putting out the least pressure. Worn bearings are a very common cause of low oil pressure on older vehicles.
Thank you for your advice Tobias, I guess I should start by switching the oil pump and, if that does not work, change the main and rod bearings then.
You'll want to eliminate other possibilities but if it gets down to bearings you'll need to check clearances and whether the crank needs to be ground undersized.
Also don't forget that worn cam bearings can cause low oil pressure as well as bottom-end bearings.