Help - Oil pressure warning light!

[cuffn]

I was driving home from work yesterday, when suddenly the 'exclamation' warning light came on dimly. No other lights at first, so checked enine temp oil pressure etc and could not feel or hear any problem with the engine. Carried on for a bit (quite a bit slower) and eventually the oil pressure warning light came on as well. I continued to keep an eye on all the gauges and the oil pressure was still up near 5 bar where it normally is and dropped slightly to around 4.5+ on idle. Got home okay and opened bonnet - no visible signs of any oil leaks and oil level when cold was just above half on the dipstick. Started up this morning and still have oil pressure warning light even though just belo 5 bar. Spoke to a guy at Northway and explained and he said it might be the oil pressure switch/sensor but I would need to take it in to get it checked. Problem is they are 27+ miles from me and they are fully booked at the mo. Any help/advice appreciated.

 

[Guest]

I have exactly the same problem in that twice now the warning light and the 'engine oil' warning lights have come on when the oil level is half way down the dipstick indicator, when I last checked. It happened this morning on my drive to work. I dropped my daughter off at nursery and when I started the car back up again the light came on. I expect that when I start it up to come home tonight that the light won't come on. Perhaps another one to add to the lengthening list of jobs to do! Any idea if replacing the oil sender is a difficult or particularly time-consuming job to do?
Cheers,

Graham

 

[danmason]

when I started the car back up again the light came on. I expect that when I start it up to come home tonight that the light won't come on.

This has always been an 'issue' with mine. Just happens on starting up after a short period of being switched off, usually only when the engine has not reached full temperature. Had always assumed the oil just hadn't had a chance to work its way back to base-camp, and took it as a quirk rather than a problem. Maybe I was wrong....

 

[cuffn]

Checked oil level while cold and above half mark on dipstick. Topped up anyway as the oil level sender can be quite sensitive (although not on at the moment). Drove the car into Northway and Ray reckons it is definately a dodgy oil pressure switch and commented on how high my oil pressure reads at idle. It has always read between 4-5 bar even at idle since i've had it but he reckons it should be between 2-3 at idle. Anybody comment on 'normal' oil pressure readings?Booked it in for pressure switch change on Monday morning so it will be interesting to see what the results are.

 

[Fen]

Graham, The oil level light is different to the oil pressure light. In your case you need a new level sensor which sits in the side of the sump. It's blimming expensive for what it is and needs the sump drained to replace it but I don't think it's difficult - I just got mine done at the next service when it happened to me.

 

[Guest]

ORIGINAL: cuffn

...It has always read between 4-5 bar even at idle since i've had it but he reckons it should be between 2-3 at idle. Anybody comment on 'normal' oil pressure readings?...

Perhaps this is an opportunity for another poll, much like the temperature one?!
It sounds like mine is very similar to yours in that it is at around half way between the dipstick marks and the normal oil pressure is between 4 and 5 bar at idle. However, I only tend to drive it about 9 miles in each direction to and from work, so I don't think that the oil is getting fully warmed through. When I have driven it for longer periods/distances the idle oil pressure falls to 2 - 3 bar, as mentioned above. Does this mean that I have the wrong car and shouldn't be ruining a perfectly good (!) 944 with these repeated short journeys?

Interestingly, like Dan my light only tends to come on when I have driven the car for a short period, switched off, nipped out and then started back up. I wonder if it is something to do with the physics of the oil, rather than a failing/failed part, such as the sender?
Cheers,

Graham

 

[944Turbo]

In my experience it is dependant on which oil you use. If I use cheaper oil when hot the pressure drops futher than with mobil one / silkolene, with these at tickover and very hot I sometimes see 3bar but it is usually higher than that, staying close to 5,
Tony

 

[colin129]

As with most of the posts, I have also experienced this problem. Most recently a couple off weeks ago, after returning from Le Mans. I topped up with half a litre of oil and the light no longer comes on.
Usually I use little or no oil between services, even with 160K miles on the clock, but the constant high rev running burnt a little off. I had the same problem of oil use after a visit to the Ring.
I seem to remember a technical evening at Porsche Centre Reading where they said that the 944 is sensitive to oil level and should be kept well topped up as when parked up on a slope, terrible things can happen when you start up. I won't stand by this comment, unless someone else can confirm it.

 

[cuffn]

Just a quick update - had the oil sender switch replaced yesterday and all is now well. Light has gone off and funnily enough the guage started reading slightly differently even before the sender was replaced (and has carried on) in that I now see the pressure drop lower at idle and dance around a bit but still with 4.5-5 bar under load. Nice not to have any light on the dash again!