996 C4s oil reading scare???

[Ikobo]

Was making the long drive from London to Scotland today, time to visit the family for Christmas. Out of nowhere the oil gauge needle plummets to zero and on the digital display it read as oil failure and requested me to check the oil level. Pulled in at the first services, switched the engine off and let the oil check do its thing, reading was fine. Car only had a full major service a few weeks back, should I be worried that this happened, or more to the point can anyone explain it? Car is under warranty, but slightly worried. It's spot on in every other way.

[6C4GTS]

You need a new oil pressure sender.....about 40 quid part and an hours labour!

Really makes your heart stop the first time it happens doesn't it?

[Ikobo]

My reaction was "oh f**k, this is going to turn in to a disaster!!". Had visions of bits of engine being visible in the rear view or something......

Still had 260 miles to go at this point, it was perfect the rest of the way after switching the engine off and letting it reset. Happy enough if that's the cost of the fix though, thanks mate.

[Barry Ashcroft]

Yep I was tanking it on the motorway nearly had a heart attack

[monthefish]

Yes, apparently quite common. Has happened to a few people on here.

If you think about it, if there was a catastrophic failure, it wouldn't be able to return to normal pressure afterwards.

[GreigM]

yup, new sender required - can be a DIY job, but a bit of a fiddle....
http://forums.rennlist.com/rennforums/996-forum/50...

[tracydeedance]

Yes very scary first time it happened to me was in my 9964S few years back
on the motorway quick dive over to the hard shoulder switched off and restarted with pressure back to normal happened a couple times after again.
Changed the oil pressure switch for about £40 all fixed never happened again.

When i got my GT3 same thing happened but less of a panic switched off restarted all fine with pressure. Oil pressure Sendor change no probs once again.
looks a very common problem.

[Ikobo]

Thanks for the info guys. Couple of other questions while we're at it!

All my warranty stuff is in the London place, but i'm up in Scotland for a six week break, can someone recommend anywhere to get this fixed and i'll just get it done while i'm here? (I'm in Fife, so guessing Porsche centre Edinburgh?)

I've only had the car a short time, but I think for peace of mind I want to keep some oil in the car just in case it runs low, which type should I buy? (The owners manual has also been left in London!)

Cheers.

[tracydeedance]

For oil nothing less than Mobil 1 fully synthetic Porsche say 0/40 I use 5/40 myself.

[GreigM]

Ikobo said:

Thanks for the info guys. Couple of other questions while we're at it!

All my warranty stuff is in the London place, but i'm up in Scotland for a six week break, can someone recommend anywhere to get this fixed and i'll just get it done while i'm here? (I'm in Fife, so guessing Porsche centre Edinburgh?)

I've only had the car a short time, but I think for peace of mind I want to keep some oil in the car just in case it runs low, which type should I buy? (The owners manual has also been left in London!)

Cheers.

As OPCs go Edinburgh are very good and I'm sure will happily look after you - however there are a number of indies who could do this job, for example:
Motortune - Shotts - very good IME, the owner Peter is a fully trained porsche mechanic and there's little he can't fix and price is always good, but busy and can be booked out a few weeks in advance, also a bugger to get to/from if you're leaving the car.
Brian Millar, Edinburgh - gets a good reputation for the older cars, no personal experience, sure he could do the job with no problem.

Oil - Mobil 1 0w40 fully synth.

As a side note - remember your car has a low oil pressure light which is a separate sensor from the gauge - to some extent the gauge is not required as few people know what it means. So long as the red low oil pressure light doesn't come on then your engine is not at risk (not from lack of oil anyway!).

[Ikobo]

I might have been a bit too quick with my "no 996 issues here" post in another thread!

So, I had the oil pressure sender replaced at Edinburgh OPC and it resolved the issue as expected. Today though, I got in the car and the digital gauge read only one bar, despite last night being one bar from the top. Got out, looked under the car, no leaks anywhere. Checked the dipstick, seemed fine, went for a little run to warm the engine up, checked the dipstick again, still good. Let the digital readout do it's thing again, still only one bar? Any ideas folks?

[monthefish]

Ikobo said:

I might have been a bit too quick with my "no 996 issues here" post in another thread!

So, I had the oil pressure sender replaced at Edinburgh OPC and it resolved the issue as expected. Today though, I got in the car and the digital gauge read only one bar, despite last night being one bar from the top. Got out, looked under the car, no leaks anywhere. Checked the dipstick, seemed fine, went for a little run to warm the engine up, checked the dipstick again, still good. Let the digital readout do it's thing again, still only one bar? Any ideas folks?

Are you talking pressure 'one bar' (or 14.5 psi)
or are you talking about quantity of oil showing on the digital oil level measurement.

[Ikobo]

Sorry, one bar for quantity on the digital gauge. Oil pressure gauge is a lot lower than normal too though, around 1.5/2.

[GreigM]

Was the car on a perfectly level surface (i.e. garage forecourt etc) - if its not level in any way it will give inconsistent readings. Also when you did the reading last night had the car been used relatively recently - if so the oil will be hot and can read higher.

Getting a good level from the porsche onboard gauge has always been a fine art. There's only 1L difference between low and high on that gauge, and the engine takes around 9L of oil so with one bar you've at worst still got 8L in there, so nothing to worry about.

As I said above, the engine has a separate circuit for low pressure warning which is really the failsafe, if it doesn't come on the engine isn't in danger from loss of oil.

[gibbon]

Ikobo said:

Sorry, one bar for quantity on the digital gauge. Oil pressure gauge is a lot lower than normal too though, around 1.5/2.

Sounds like you may need a topup of oil, i would consider taking to a trusted garage though to check over if it was mine.

[river_rat]

The digital readout on my 996 always seemed to give different readings, from day to day, even when parked in the same place.

[Jay964rs]

My 996 turbo gives various readings (one or two bars, up or down), but I always make sure its at least half way on the digital readout.

[anonymous-user]

You are only supposed to take a reading when the car is fully warmed up and been standing on a level surface for several minutes. Otherwise it can be misleading if the oil is cold. Same when reading the dipstick - fully warmed engine, level ground otherwise don't bother. I find that my digital gauge tends to read a bit lower than the dipstick, but it does seem fairly consistent. Readings from cold are quite variable as you might expect.

[Ikobo]

uktrailmonster said:

You are only supposed to take a reading when the car is fully warmed up and been standing on a level surface for several minutes. Otherwise it can be misleading if the oil is cold. Same when reading the dipstick - fully warmed engine, level ground otherwise don't bother. I find that my digital gauge tends to read a bit lower than the dipstick, but it does seem fairly consistent. Readings from cold are quite variable as you might expect.

As I said in the earlier post, I took the car for a drive to warm it up, still read practically zero on the digital readout despite the dipstick showing good level. The car was on level ground.

[GreigM]

uktrailmonster said:

You are only supposed to take a reading when the car is fully warmed up and been standing on a level surface for several minutes. Otherwise it can be misleading if the oil is cold. Same when reading the dipstick - fully warmed engine, level ground otherwise don't bother. I find that my digital gauge tends to read a bit lower than the dipstick, but it does seem fairly consistent. Readings from cold are quite variable as you might expect.

I thought the wet sumped M96 engine is supposed to be taken cold, as the oil needs to be sitting level in the sump - if its been used the oil will still be dripping down and not give an accurate reading.

The dry-sumped GT and Turbo cars should be taken at full temp.