low oil pressure

[kevin]

I am looking to buy a '91 500SL with a genuine 41K miles on the clock. However, when the engine is warmed up the oil pressure at tick-over is only 2 Bar on the gauge instead of the usual 3. The service book is a bit sketchy regarding regular sevices and the last service was carried out at a "Car-Care Service Centre".
Bearing in mind that the milage is genuine and the car has been driven with care by one lady owner since new could it be a simple matter of a sub-standard oil filter/oil being used at the last service or is something more sinister lerking under the bonnet?
I would be grateful for any comments or other members experiences prior to purchasing this car.

Regards, Kevin.

 

[Steve_Perry]

Have you taken the car for a drive? Typically the pressure should be 3 when your driving along. If the car is at standstill/idle and fully warmed up then a pressure over 2 should be okay. My old '86 190E used to idle at a pressure of approx 2.3. Actually, anything over 1.5 at idle should be okay or so I have been told. The main thing is that the pressure should increase to 3 once the car is in motion.

If you want real peace of mind then get an AA mechanical inspection/check performed before you buy, that should throw up any potential problems.

S.

 

[Ian B Walker]

Oil Pressure at tickover Minimum 0.3 bar.Oil Pressure at 1500rpm 3 Bar.

This is according to the Not so Great God Haynes.

cheers
Ian

 

[jaymanek]

Yeh the big engines dont tend to keep to the full 3 on idle. My 420 stays at about 2 on idle.

Main thing is that it stays at 3 above 1500 rpm or so.

 

[kevin]

Many thanks for the info. I'll let you know how I get on.