Just Finished 996 cluster into 986

[obthomas]

I just finished putting a 2002 996 instrument cluster into my 03 986 boxster. I am pleased to report that everything went perfect. I even got the On Board Computer to work full feature.

The one surprise is the new oil pressure sender and gage operates like a tachometer.
Once the engine is to operating temperature the gage is around 1/2 bar at idle and about 4.5 bar at 2-3000 rpm. I never knew the oil pressure fluctuated like this with just a warning light. Now I am not sure I like having an oil pressure gage.k:

Anyone know the best way to raise the oil pressure at idle?:dance:

[Robert986]

There is a revised version of the oil pressure regulator piston 99610712551, you may try that!

[Homeoboxter]

Are you sure the sending unit and the gauge match each other?

Oil gets thinner at high temperatures, so the lower pressure is normal. 1/2 bar sounds a bit kind of low, i don`t know the factory specs though.

As long as the oil pressure lamp does not start flickering at idle when the engine is hot, I think you are on the safe side. You can measure the oil pressure with a mechanical gauge, that should give you a precise readout. What you can also try is to wait till the oil is hot and then try to reduce the engine speed from idling and see when you reach the threshold for the oil lamp to turn on. You can do this if you switch to gear and slowly release the clutch while pressing the brake pedal. If you can`t make the lamp turn on without killing the engine, you are good. If the lamp starts flickering right away the engine speed drops, you have a problem.

If you want higher pressure at idle one possibility is to use oils that are designed for staying thicker at high temperatures. I use 10w-60 oil in old air cooled motorcyle engines that operate at higher temperatures and have high oil clearances, especially when they are worn.

[pilot4fn]

I swapped the OPRV (piston and spring + washer) to an updated version and after the change the cold start rattle disappeared as well as the engine seems more responsive from low revs.
This OPVR (Oil Oressure Relief Valve) should improve the low rpm oil pressure. The piston is a bit different shape adn also the spring is slightly longer.
I purchased these updated parts directly from local Porsche Center:
Piston 997.107.125.01
Spring 996.107.127.53
Gasket 996.107.123.50

Here's the old:


Here's the new:

[flmont]

Where is this OPRV located Thanks Frank

[obthomas]

front of the engine right at the bottom of the oil pump.

[pilot4fn]

Originally Posted by flmont

Where is this OPRV located Thanks Frank

[flmont]

Thanks pilot and obthomas,..I would not have known its located there.I have the parts and will do that ASAP..Thanks !!

[obthomas]

Originally Posted by Homeoboxter

Are you sure the sending unit and the gauge match each other?

Oil gets thinner at high temperatures, so the lower pressure is normal. 1/2 bar sounds a bit kind of low, i don`t know the factory specs though.

The gage is from a 996 and the sending unit is also. The sending unit is new. Both are made by VDO. I think the gage and sending unit are a match.

I find that the 03 boxster oil pressure is indeed between 5 bars cold and 1 bar hot at idle.

This seemingly low oil pressure at idle is acknowledged in the forum and most recommend the oil pressure relief spring and cylinder be upgraded.

Thanks for all the responses. Will let you all know if the upgrade works.

[berni29]

Hi

Very interesting. This is something I am looking to do if I can find a cheap enough set of instruments.

Berni

[beater986]

Is the 996 cluster supposed to have real-time oil pressure? Is there any downside to this over an aftermarket gauge?

[obthomas]

The 996 instrument cluster has a 0 to 5 Bar analog gage. It is real time as opposed to some kind of averaging or dampening. Mine moves like a tachometer. To be clear, I was not and am not getting a low oil alarm.

I just installed the new oil pressure relief spring and cylinder. NO HELP AT ALL. I was kind of thinking how does a relief valve, not a regulator, help oil pressure at an idle. Well as predictable the answer is it doesn't.

I am now going to do 2 things: get a mechanical gage hooked up to check the 996 gage and go to a something W 50 weight oil for more viscosity at operating temperature.

Will be back in a few days.:dance:

[Seadweller]

Originally Posted by pilot4fn

I swapped the OPRV (piston and spring + washer) to an updated version and after the change the cold start rattle disappeared as well as the engine seems more responsive from low revs.

Just to be clear, updating this part stopped your cold start rattle? I'd be thrilled to death if it would work for me.

[pilot4fn]

Originally Posted by Seadweller

Just to be clear, updating this part stopped your cold start rattle? I'd be thrilled to death if it would work for me.

Yes, the cold start rattle is now gone after the OPRV update :dance:

[Vza]

Hi,Is this the cold start rattle many boxster owners complain about? Happens briefly at startup then immediately goes away. I have it as well. The oprv upgrade will solve it? V

[obthomas]

Just changed oil to 20W50 and got a full number on the gage. Instead of idling at 1/2 bar I now idle at 1 1/2 bar.

[gva-sfo]

Well done, you are ahead of me !
I'm still having "coding problems", i.e.: my cluster donor was a 996 coupe, and I understood that it should be recoded to become a cab ..in order to have the roof lights (on center lower dashboard) working.
Anybody has the byte location and content, ..to recode Coupe to Cab in cluster code ?

[Qingdao]

Originally Posted by obthomas

The one surprise is the new oil pressure sender and gage operates like a tachometer.
Once the engine is to operating temperature the gage is around 1/2 bar at idle and about 4.5 bar at 2-3000 rpm. I never knew the oil pressure fluctuated like this with just a warning light. Now I am not sure I like having an oil pressure gage.k:

Anyone know the best way to raise the oil pressure at idle?:dance:

Idle is hard on an engine. Lowest oil pressure, lowest air flow, and lowest coolant movement. It bothers me when people just let there car's idle.

1/2 bar is pretty low. Looks like some thicker oil helped you out; good enough.

[piper6909]

Originally Posted by obthomas

Just changed oil to 20W50 and got a full number on the gage. Instead of idling at 1/2 bar I now idle at 1 1/2 bar.

I don't know how cold it gets down in TX, but too thick of an oil is really bad during probably the most critical time for engine wear (besides extreme driving): Cold starts.