Hi Michel, it depends to a considerable degree whether the engine is cold or hot. As far as I know, the acid test relates to an engine at normal operating temperature, that is about 87 degrees centigrade.
If the reading is one bar, with engine idling and in gear, AND sitting at traffic lights, that ought to be okay - naturally, you'd want it to get to three bars once you start accelerating and driving at normal speeds - say 1500 rpm should hold the needle comfortably at three bars. However, you may well find that on SLOWING DOWN, the needle well quite readily drop from the three bar maximum down to two and a half, and then two, as you are further slowing down - the gradual slowing down is not something that I like, but I honestly don't think that it should be an issue one would have to worry about.
Just as a matter of interest, on ROVERS with the 3.5 litre V8 engine, there is an oil pressure gauge reading up to 60 lbs./sqin., but the normal reading, at 1500 rpm, with engine at normal operating temperature, should be about three bars.
On said ROVERS, there is also an oil pressure light which comes on at a reading of 7lbs./sq.in. or lower. Now, years ago I had a 3500 with 'poor' oil pressure reading, with the light coming on quite readily, even just slowing down. I drove that car for about two years without any apparent ill effect. When I pulled down that engine, its internals were certainly no worse than any other I had pulled down.
On 'Gleaming Beauty', we have had a couple of pretty hot days recently, and at idle, with "D" engaged, the oil pressure would be just below the '2' bar mark, but if the lever was pushed to neutral, the engine would just reach two bars. I consider that excellent, given the fact that "GB" is running slightly higher operating temperatures on account of a slightly faulty viscuous coupling. Hope that answers your query. Regards Styria
