Oil pressure needle 'flickering' (944 S2)
Discussion
A question for the more technical chaps on here ...
While sitting at some lights last night in my 944 S2, I noticed that the oil pressure gauge was not steady. The engine was nearly fully warm, and the needle at idle flickered from about 4.25bar to a bit over 4.5 bar. It wasn't a regular flicker, just jumped around slightly with time. The idle was rock-steady, so it wasn't associated with a change in revs. I'm not worried that the pressure isn't high enough - it holds excellent pressure - it's the movement which causes me to raise an eyebrow.
What causes this, and is it something I should worry about?
Oli.
While sitting at some lights last night in my 944 S2, I noticed that the oil pressure gauge was not steady. The engine was nearly fully warm, and the needle at idle flickered from about 4.25bar to a bit over 4.5 bar. It wasn't a regular flicker, just jumped around slightly with time. The idle was rock-steady, so it wasn't associated with a change in revs. I'm not worried that the pressure isn't high enough - it holds excellent pressure - it's the movement which causes me to raise an eyebrow.
What causes this, and is it something I should worry about?
Oli.
4.5 bar hot at idle is very high for an S2 - it is more usually 2-3 bar - but you may have a very tight engine or low mileage or the guage might not read right - check it with the engine stopped but ignition on - to see if it reads zero.
The new type oil pressure relief valve fitted to these cars had a central piston that opened and closed the byepass giving a faster close and keepin oil pressure higher at tickover. I don't find anything in your notes to worry about - perhaps only be pleased about.
The instrument cluster is made with flexible thin foil circuits that can also give problems with time and mess up readings as voltages vary.
All sounds just fine to me - I hope so.
Baz Hartech
The new type oil pressure relief valve fitted to these cars had a central piston that opened and closed the byepass giving a faster close and keepin oil pressure higher at tickover. I don't find anything in your notes to worry about - perhaps only be pleased about.
The instrument cluster is made with flexible thin foil circuits that can also give problems with time and mess up readings as voltages vary.
All sounds just fine to me - I hope so.
Baz Hartech
Baz,
Thanks for the answer.
It's done 120k miles; the pressure was at nearly-warmed-up. When warm, it's between 3 and 4 bar (usually nearer 3), just as you say. And yes, the gauge does measure '0' when it's on but not running.
Thanks for the reassurance. I was half-wondering what caused it (I could understand a fluctuation in pressure with a varying idle, but when everything else is constant then I can't quite understand why the oil pressure is not constant) and being a little paranoid (one day soon something on this car will cost me money, but I'm not in a hurry to reach that day!)
On a side note, it's good that there are people on here who can offer very detailed knowledge of these cars, from an experienced point of view. Thanks for your continued input (and to chaps like willdew, wildoliver etc).
Oli.
Thanks for the answer.
It's done 120k miles; the pressure was at nearly-warmed-up. When warm, it's between 3 and 4 bar (usually nearer 3), just as you say. And yes, the gauge does measure '0' when it's on but not running.
Thanks for the reassurance. I was half-wondering what caused it (I could understand a fluctuation in pressure with a varying idle, but when everything else is constant then I can't quite understand why the oil pressure is not constant) and being a little paranoid (one day soon something on this car will cost me money, but I'm not in a hurry to reach that day!)
On a side note, it's good that there are people on here who can offer very detailed knowledge of these cars, from an experienced point of view. Thanks for your continued input (and to chaps like willdew, wildoliver etc).
Oli.
Gassing Station | Porsche General | Top of Page | What's New | My Stuff