Oil change - now temp only goes to 94?

[DJMC]

40k major service of my 981 2.7 PDK completed by OPC last Friday, including new oil and filter.

Just been out for a long run. Water temp up to 90 degrees as usual but oil always used to go to 105 degrees whereas now it doesn't go past 94.

Also, oil level at 3 green bars out of 5 whereas I've never known it to be less than 4 bars.

I can't see why clean oil and a new filter would drop the temp, especially as it didn't after its 20k oil service.

Waiting for OPC service manager to call me, but any ideas?

Thanks all.

[Monch]

as a guess, you may have pressed the sport button, which opens up other radiators, thus cooler oil temp.
well at least it does on a 991...

[Twinfan]

Yep, 981 is the same. 90 degrees in sport mode for oil, 110 in normal mode.

[DJMC]

I did briefly have it in Sport then went back to normal mode for at least 10 miles. I had thought about Sport lowering the temp so expected a shift upwards back in normal.
OPC service manager had no explanation and is taking it back in next Tuesday. Didn't mention Sport as a possibility.

[DJMC]

Twinfan said:

Yep, 981 is the same. 90 degrees in sport mode for oil, 110 in normal mode.

110? I thought it stopped at 105? Mine has, for the last 27k miles.

[Twinfan]

I rarely use normal mode, but I'm pretty sure on my car it goes up to 110.

[bob2146]

DJ: you actually need to use the pedals . 40+ mpg (from the other thread) in a sports car is bad for the engine. Drive it like you stole it and your mpg (and temperatures) will be back with the rest of us in no time, i.e. firmly 20s not 40s mpg. You may even start to enjoy the car

[DJMC]

bob2146 said:

DJ: you actually need to use the pedals . 40+ mpg (from the other thread) in a sports car is bad for the engine. Drive it like you stole it and your mpg (and temperatures) will be back with the rest of us in no time, i.e. firmly 20s not 40s mpg. You may even start to enjoy the car

And who are you? James *unt? I prefer to be sympathetic to my car, not accelerate then brake hard all the time. If you knew my motor racing background you'd not be so glib.

[DJMC]

Took it out yesterday for 60 miles to monitor oil temp. Here's what I noted:

- Oil temp was 11 degrees at start up and didn't increase from this for two miles.
- I drove for 30 miles in Normal mode, the oil temp took 20 miles to get to 90 degrees, hit 101 at one stage after that, but then went back down to 95 average.
- Until the recent service, over 27k miles in my ownership, the oil has always hit 105 degrees and stayed there.
- At 30 miles I shifted to Sport mode. The oil temp dropped to average 87 degrees.
- I came off the motorway and shifted back to Normal mode. The oil temp dropped to 81 degrees as I came to a rest at traffic lights.
- Onto motorway again and the oil temp went back up to around 95 average, but fluctuated 3-4 degrees either way up to 99 max.
- Off motorway onto A road and oil temp was flutuating between 97 and 93, changing every 30 seconds or so, not particularly in line with what the car was doing.
- Oil pressure on the motorway at constant 70mph was 2.2-2.3 BAR. With foot down, and a gear down under acceleration, this would go up to 3.5 BAR.
- The main oddity is the oil temp constantly changing up and down when the car is fully warmed up. It's never done this before.
- I have always driven with the "vehicle information" screen on, showing water and oil temp etc., hence noticed this change.

I'd say faulty sensor, but why right at an oil change? Or perhaps a blockage near the sensor preventing a continuous flow of hot oil getting to it (unlikely). Any other ideas? Does your 981 oil temp fluctuate up and down once fully warm?

[Twinfan]

Nope. It's rock solid unless I change driving mode, only varying by the odd few degrees.

[DJMC]

OPC are collecting on Tuesday to investigate.

Either my oil temp sensor has suddenly become the most sensitive there's ever been, or there's a display fault, or the sensor is faulty.

[Milnsey]

Oil temp on mine fluctuates according to driving style. Always use sport plus mode, it will vary between low 90s and 105ish

[DJMC]

Milnsey said:

Oil temp on mine fluctuates according to driving style. Always use sport plus mode, it will vary between low 90s and 105ish

So it does go up and down once the car is up to temp? Which model is yours?

Of course it WOULD be better if it did actually reflect the oil temp, rather than staying rock solid as it always did before, but 81 in Normal is too low surely? Plus, how can it sense temperature change every 30 seconds? Does yours change this often?

[bcr5784]

My oil temperature is generally in the low 90s in Normal and always has been, so I'd be interested to know if that's wrong. Don't often use sport - use manual in Normal when getting sporty.

[DJMC]

bcr5784 said:

My oil temperature is generally in the low 90s in Normal and always has been, so I'd be interested to know if that's wrong. Don't often use sport - use manual in Normal when getting sporty.

I was thinking about that... may be better to switch to Sport when getting sporty so as to bring the oil temp down as designed into the Sport button? Pressing it is supposed to drop the temp 10 degrees.

When you say "low 90s" does it get to a certain level and sit there, e.g. 93, or does it fluctuate up and down?

Over the past few years I've occasionally noticed posts about oil temp generally reporting the temp "gets to 105 and stays there" and that it won't reflect the actual oil temp. I seem to recall cmoose explaining this when I'd previously thought there was some clever stuff which limits the temp to this figure precisely when it's just electronics using 105 effectively as a "green light" for temp, not the actual reading.

[Twinfan]

I think that's water temp. Mine never moves from 90 once warm.

[DJMC]

Twinfan said:

I think that's water temp. Mine never moves from 90 once warm.

Same here, water has always got to 90 and stuck. Still does.

[bcr5784]

Twinfan said:

I think that's water temp. Mine never moves from 90 once warm.

No I do mean oil temperature. TBH I don't watch it that assiduously as I never track the car so can't say exactly how it varies, but as I say it is always 90 or just above whenever I look.

[bcr5784]

DJMC said:

bcr5784 said:

My oil temperature is generally in the low 90s in Normal and always has been, so I'd be interested to know if that's wrong. Don't often use sport - use manual in Normal when getting sporty.

I was thinking about that... may be better to switch to Sport when getting sporty so as to bring the oil temp down as designed into the Sport button? Pressing it is supposed to drop the temp 10 degrees.

When you say "low 90s" does it get to a certain level and sit there, e.g. 93, or does it fluctuate up and down?

Over the past few years I've occasionally noticed posts about oil temp generally reporting the temp "gets to 105 and stays there" and that it won't reflect the actual oil temp. I seem to recall cmoose explaining this when I'd previously thought there was some clever stuff which limits the temp to this figure precisely when it's just electronics using 105 effectively as a "green light" for temp, not the actual reading.

I use normal rather than sport as changes are a tad smoother then. I tend to think that a somewhat higher oil temperature to boil off the water content in the oil is no bad thing within limits.

[Milnsey]

DJMC said:

So it does go up and down once the car is up to temp? Which model is yours?

Of course it WOULD be better if it did actually reflect the oil temp, rather than staying rock solid as it always did before, but 81 in Normal is too low surely? Plus, how can it sense temperature change every 30 seconds? Does yours change this often?

Yes definitely fluctuates when up to temp. Model is CGTS. 81 in normal does sound too low. Temp reading does change every 30 secs or so if driving style alters, however on a steady motorway run it will read 94 in sport plus and about 104 in normal. After a blast on local country roads I leave it to idle on driveway for a couple of mins and temp will drop down to low 90s fairly quickly