jim010

Agreed. I will do so. Ordered the spring, piston and gasket. I'll wait until these come before changing the oil.

Imo000

Stop throwing parts at it!

Identify the problem, be 100% sure that it IS the problem and ONLY then buy the part/s that are needed for the repair. You are going in 10 different direction all at ones, this will not end well.
Step 1: Check idle speed and go from there.

Macster

One has to be aware of what is "normal". I didn't know the oil temperature for my Boxster or Turbo engines, but in one case the Boxster coolant temperature got up to 226F. This when being driven -- in town -- in 116F ambient temperature. I expect the oil was at least that hot probably hotter.

For a loaner Macan when just being used normally as my commuter vehicle -- and certainly not in 116F ambient temperature -- the oil temperature got quite a bit hotter than 230F. While I can't recall the oil temperature now it was "way" above what I expected to see so much so I spoke with the SA and senior tech at the dealership and both told me the oil temperature I was seeing was "normal" for this vehicle.

For my Hellcat the oil temperature can reach -- this in town driving -- 230F (and I've never seen it go higher). But even with the oil temperature this high the coolant temperature is around 210F.

As I mentioned in another post, even with the oil at 230F the oil pressure drops just a few PSI from what it is at 212F. I use 212F temperature as a base line as this is the temperature at which the "40" in "0w-40" is obtained. IOWs, oil at 212F is not hot it is at its working temperature.

My point is unless the engine is running very very hot oil pressure shouldn't fall off but just a few PSI.

There is a problem replacing the oil pressure relief spring and piston. The spring may be the wrong one, it may be bad, the piston may not fit properly or may have a burr/nick and may bind.

It all boils down to ensuring the idle speed is in spec and then checking the oil pressure to verify the oil pressure sensor in the engine is working properly. If the idle speed is ok and an independent verification of the oil pressure find the pressure low at idle -- though in all the factory documentation I've seen regarding oil pressure it is called out at some elevated RPM and at some elevated temperature so I do not know what constitutes low oil pressure at hot idle (other than I guess the low oil pressure warning light flashing maybe...) -- then one can possibly consider a new oil pressure relief spring and piston.

But the problem -- if there is a problem -- can be due (for example) the pressure relief valve that controls oil supply to the piston oil jets. If this is not working properly it can fail to close when oil pressure drops below some low threshold. Normally if oil pressure drops below some threshold the valve should close thus helping to ensure sufficient oil pressure and supply to the main/rod bearings and the camshafts/lifters.

jim010

Update for those that have the same issue as me.

We replaced the oil pressure relief spring and piston. with the updated 997 piston and new spring and new crush washer. The old parts looked fine, though, and it already had the updated piston. Only lost a cup of oil. Oil looked good, and no surprises in it. Maybe the spring was weak, idk, but I doubt this will solve the problem. Was cheap to do this, so not a biggie. For others that had this problem, what did you do?

Imo000

Did it fix the problem?

Mike Murphy

I would still take the advice already given in this thread:

1.) Make sure your engine idles at last 625RPM. Hitting the AC button should bring idle to 800. The oil pressure is directly related to engine RPM, as the oil pump is driven off the engine.
2.) Attache a certified oil pressure gauge and measure the oil pressure. Your sender or gauge might be off by only 1/4-point, which is enough to make a big enough difference.
3.) Drop the sump plate if you haven't already and inspect the oil pickup; remove any and all debris from the pickup
4.) If all else fails, and you know your engine is healthy, it just might have loose tolerance. In that case, increase your oil viscosity by switching to a 50w oil. Only do this if the cold start temps are above freezing. If you drive is freezing cold temp, I'd stick with 0-40 or 5-40 in the winter.

Noz1974

Also if your running a standard filter housing, check that the filter hasn't been over tightened, this can cause the paper insert to twist , collapsing the pleats in the filter reducing flow!

jim010

Well I ordered a new oil filler cap so we can make an adapter for the mechanical oil pressure gauge. So that is my next step. Its a neat idea that I came across on here.

We don't drive in winter so if all else fails we will up the oil viscosity. When we changed the oil last, the filter was fine. Not crushed or anything, and no glitter or debris. Oil was good. Sent a sample off to Blackstone.

I'll update when when get the adapter made and tested the pressure.

JohnCA58

Well I ordered a new oil filler cap so we can make an adapter for the mechanical oil pressure gauge. So that is my next step?

Don't understand this one, did you mean to make a adapter fitting for the oil pressure sensor to run mechanical gauge ?

Quadcammer

why bother with that when you have two ports on the heads for specifically that purpose

Imo000

How are you going to measure oil pressure with the filler cap?

jim010

I got the idea from here:

https://rennlist.com/forums/996-turb...-pressure.html

I like that it would be quick and easy to do this, rather than mess around with the oil sender unit. There a reason it would be bad? An extra cap is nothing to get.

Noz1974

You need to be connected to the main oil gallery for oil pressure, there is a removable plug on bank one head , this oil filler cap thing, I think you are confusing oil pressure with measuring the crankcase breather efficiency like if you had a bad AOS and was using a manometer, that's something completely different !

DBJoe996

Just to reiterate - you cannot measure the engine oil pressure with the oil filler cap. The thread you quoted says that they put a fitting on the engine filter canister and measured the engine oil pressure there.

Imo000

No, the quote says filler not filter.