This morning on my drive to work, I noticed that under throttle tip in, the oil pressure reading would drop a little (maybe 2 needle widths worth). The car runs fine, makes no weird noises, and that could be completely normal...but I've not noticed it bounce before.

I tried to search the archives, but either I'm not searching for the right things, or not everyone has this. Thoughts?

 

This has been covered before here at various times but I do not recall any specific threads or keywords.

Key words jumping, jumpy, erratic oil pressure might turn up something.

My 03 manifests this behavior at various times, and I have found nothing to explain the behavior's inexplicable appearance and just as inexplicable disappearance other than it appears -- it seems -- to be more common in hotter weather.

It is clear from the rapidity of the gage's change in reading the reading changes do not can not reflect real changes in oil pressure. Gear oil pumps do not vary their volume and pressure output by 1 or more bars of pressure in a fraction of a second. The behavior strongly suggests a connector/connection problem.

Now the above conclusion might have arisen from me having described this behavior to the techs where I have the car serviced and a marginal connection/connector might have been mentioned.

Regardless I've not bothered to look into further though the next time I take the car in I might pursue this a bit more and see what corrective action there is available.

The behavior while I'm used to it is still a tiny bit unsettling, not in the sense of having me beleiving the engine is losing oil pressure, but just that one doesn't expect a car of this caliber having a twitchy/flaky oil pressure gage.

Sincerely,

Macster.

 

Thanks Macster, I thought I'd seen it before, but couldn't come up with a decent search result.

 

Some say that when in the 2,000 rpm range and you hit the throttle, the oil pressure fluctuates due to the variocam actuactor. Once above the 3,000 rpm range no variance happens! This variance shows up as a jump from a higher registered pressure to about one bar lower and quickly back again. I have no proof of this but this was offered to me on more than one occassion. Not sure if this is what you are seeing.

 

This happens to me as well. Same symptoms as OP. I just always assumed it was because the car is 10 years old.

 

Dropped off my Boxster this AM at the dealer and went to the service area to speak to a tech about the this 996 Turbo oil pressure jumpiness.

I asked the tech if it was due to an electrical connector/connection problem and he said "maybe".

Then my shuttle ride arrived and I had to leave before I could submit follow up questions.

I'll see if I can get more on this when I pick up the car.

Sincerely,

Macster.

 

I've noticed mine will take a small dip in this situation, but it's not what I would describe as "jumpy". It's a small dip and then comes back up, but the motion of the needle is smooth and it doesn't move around under constant throttle.

 

This is probably a better description than mine. I was invoking it on purpose, thus the jumpy idea. It does seem quite normal, but I like the idea of knowing why as well.

 

Today I closely observed the oil pressure while in 1st gear at just under idle. As I gave the engine some very gentle throttle as the rpms climbed the oil pressure climbed.

I did see some slight movement of the needle that was *not* linear but I could detect no pattern even after several tries.

If it arises from the VarioCam Plus system being activated/deactivated I can't say.

Sincerely,

Macster.

 

Try cruising along in say 2nd or 3rd at 2000, RPM. Then hit the throttle pretty good (not WOT) and see if it takes a slight dip. that's where I have noticed mine.

I have always assumed that when the pressure is not near the peak due to low RPMs, and then you suddenly hit it, there is a slight delay between the engine's demand for more oil flow and the oil pumps ability to build pressure.

That may be a bad assumption.

 

Did this ever get resolved?

 

I tried this the other day with no success. If the VarioCam Plus system is bleeding away oil pressure I can't say yes or no with any certainty based on what I saw.

The engine's oiling needs with throttle is mainly a need for more pressure but because higher pressure (oil pressure and bearing pressure) forces more oil out of the bearings the volume of oil required goes up. The oil flow from the bearings helps carry heat away from the bearings too which is a good thing.

Based on what the techs tell me about the newest generation of engines with variable oil pressure control they told me at first it was a interesting to give the engine some throttle and see the oil pressure climb as it did with the previous generation of engines but then come down -- not too fast but it does I guess come down pretty quickly -- from 4 to 5 bar to around 3 bar. The techs say that is plenty of oil pressure even at pretty high rpms. I do not the oil pressure curve though throughout the rpm range of the engine.

Sincerely,

Macster.