OIL PRESSURE

[snarf]

I reported a similar problem in an earlier post. OPC; reluctant to take my word that there was an intermittent problem, suggested leaving the car with them so they could verify the fault. As this might have taken several months I naturally declined this offer. The next time the oil temperature was 90+ and the oil pressure reading was stuck on 5 with the engine on tick-over I took a photograph of the instrument readings. As a result the OPC agreed to investigate and subsequently changed the oil pressure sender. Problem solved (Just remembered I need to add this to Gary's warranty post)

 

[stuey]

Hi Guys,

I need your feedback and input please. On my drive to work this morning when I took the car off the drive I noticed that the oil pressure was nailed at the 5 even at low speeds and low revs. This did not change until the car was fully warm. Then it started to fall closer to what it should and has always been like (lower revs between 2-3 higher revs 4-5).

I have read previous posts on this forum on this subject, but still none the wiser really. Any suggestions as to what it could be?

Any input would be greatly welcomed.

Cheers Stu

 

[adrian996]

Hi Stuart. I've read your post a few times now and I can tell you that there's absolutely nothing wrong with your car. The oil pressure on the 996/997 engine should read 5 bar at start up when cold. This is partially due to the increased viscosity of the oil when it's cold. As the engine warms up the oil pressure should drop and settle around 2.5 to 3 bar at tick over. If you rev the car at this point you will notice that the oil pressure rises and falls again - just the same as your tachometer (revometer) - you're increasing the oil pressure when you rev the car and decreasing it when the engine settles back to tick over again. It's always a good idea to use the oil pressure gauge as a sure indication of knowing that your engine is up to working temperature before you put the engine under any pressure (revving it above 2,000 - 2,500 when cold for example). When the oil pressure is settled at around 2.5 bar at tick over you know that you can then let the fun begin without damaging your engine. This is a better indicator than just using your water temp gauge. I would imagine that any dodgy car mechanics would gladly take your money to investigate this 'problem'. It would take a very long time to cure though!![] Adrian.

 

[snarf]

Adrian - you're right I jumped to the conclusion that Stuart was experiencing the same problem as I did.

 

[stuey]

Cheers Guys, thanks for your input. One thing though Adrian this has never happened before. Today though the needle was stuck at 5 for around 15 miles even at low revs (1500 - 2000rpm). It only started to fall when I was just a short distance from work and even then it fell down to 1.5. By this time the engine was & had been fully up to temp for a while. When I parked up it then started to behave normally - I kept blipping the revs and it rose up & down as normal. Normally for my car from cold it does not go straight to 5 & stick there, it is usually around 4.5 - 4 and depending how I drive usually rises and falls. I try never to boot it until all indications show engine is fully up to temperature, so that is why I found it strange to be stuck at 5 this morning. It did have an oil change last month, but it has never behaved like this before & had car 14 months. Will keep a close eye on it & let you know any further developments - thanks again. Stu

 

[adrian996]

No problem. I might be wrong but I would guess that you may have been running very slightly low on oil for a while prior to your oil change and, now that it has been replenished, you are only now noticing that she's running at what you think is higher than normal(?). But be assured that it isn't. The oil pressure needle should be wedged right up against the limiter until she's warm. Adrian.

 

[garyw]

Mine sits bang against the top of the gauge when its cold or at revs.. only time it drops is to about 2.5 on tickover and hot. All other times its reading a happy 5 [] I think Adrian has pointed out what it could have been... garyw

 

[stuey]

Cheers all for your input. Panic over as they say. [][][][] Stu

 

[JAH]

Now I'm panicking!! I've got a one year old gen2 997 c2s. On start I get an oil pressure of 2.5 to 3. When I accelerate it goes to 4 or a bit higher and then returns to 2 to 2.5 when cruising. Been like this since I bought it - also a mate with a gen2 997 says his readings are the same as mine. Do the gen2 engines behave differently?? Jonathan.

 

[adrian996]

It's quite possible that the Gen 2 engine behaves differently to the 997 & 996 - but I'm not sure, sorry. It's a DFI engine so it is quite a different set up to the indirect injection.

 

[tscaptain]

Yep, they sure do! That's because they have an electric oil pump (supplies pressure as requested by some computer somewhere!) instead of a mechanical one which is simply rev driven. Try driving along at a steady speed and then plant your right foot. The oil pressure increases almost instantly and way ahead of the rev increase. What you see is perfectly normal.

 

[JAH]

ORIGINAL: tscaptain Yep, they sure do!  That's because they have an electric oil pump (supplies pressure as requested by some computer somewhere!) instead of a mechanical one which is simply rev driven.  Try driving along at a steady speed and then plant your right foot.  The oil pressure increases almost instantly and way ahead of the rev increase.  What you see is perfectly normal.

Thanks for this - I'll stop panicking !! Jonathan

 

[c2s]

I needed to ask something about the clock display but my 997s is at Porsche bodyshop having a upgrade so cant take a photo. anyone has a photo os a set of gen1 997s clocks to post up so I can make double sure I get the right info before posting a "maybe" problem

 

[tscaptain]

Here's a turbo dash - exactly the same though as I recall (apart from word "turbo" in the middle and the red line!)

 

[c2s]

Thanks, thats great. The clock at the far left, that goes to 90-105 and I am not 100% but when it hits 100 the loud fan comes on behind my right raidator, loud.. All this time I though that was temp I have no idea why, really stupid of me, my oil (far right) hits 5 on high revs but normally sits at a nice 3 while driving. The thing that has been bothered is the left clock what should that be sitting at, it has never went any higher than 105. thanks for photo.

 

[tscaptain]

Left clock, oil temperature, will vary according to how hard you are driving but the normal range is around 80-110. Never seen it higher than that even on track. BTW, what revs do you need to get the oil pressure to "5" when it's warmed up?

 

[c2s]

when its warmed up and its sitting it at 5 its normally when I am flooring it, but it drops all the time depending on what gear I am in normally 3 revs is around 3.5. as for the left clock it would never be 80 for me after into a 5 mins drive, its always 90 -105, never went above that. it just seems funny how thats when the fan comes on or maybe I ws looking for that

 

[STiG911]

Okay, this may be academic, but I had a similar thing with my 2005 C2s last month. I found that the drivers side fan would come on full-force most of the time, with no apparent action from the nearside (no hot air blowing out either) After checking 'the forums', I found that the passenger side fan can get stuck sometimes as, being near the nearside (duh) of the road, all sorts of detritus can get in through the vents in the arch liner jamming the fan blades. I spoke to Paragon (car only new to me 4 months) as I was hesitant about doing this myself despite years of fixing all my other cars myself (Generally don't trust garages) but after a chat, decided to tackle the issue. so, remove the front nearside wheel, use a torx bit to undo 6 screws from the lower arch liner and trailing underside of the front bumper. Remove the arch liner and Holy Pants - all sorts of silt and stones jammed between the fan and the cowling. Once removed and reassembled. Short drive to warm the lady up, sit for a bit and Hey Presto! No more Jet Fighter fan noise. Both fans working in unison, like they should do. Happy days.

 

[garyw]

Excellent report on that Stig, glad it was resolved so simply... garyw

 

[c2s]

hey stigy, awesome post. I will give this a go on Friday, atm the fan is turbo charged and 100% sound like a jet fighter taking off. I will keep you posted, thanks for replying.