Oil PSI question/problem.....

[AJKS]

I have a 94 79K mile NSX. It is the very fast for a factory stock car. Fastest of my 3 NSX's. Will beat a 97 up car in the 1/4 mile by .1-.2 12.9 best. So engine is strong.
This is what it does.
Outside air temp is not a factor. This strange PSI problem will happen when it is 60 deg or 100 deg outside.
Sometimes the oil PSI is 1 on the gauge at 800 rpm and 4 at 3000rpm, It will not go much higer than 5 at high rpm. At any given time the oil PSI may jump to 2 at 800rpm and 6 at 3000 and go all the way to 7.5 when high rpm. in any case the oil PSI does drop a bit like it should when V-Tech come in. On some occasions the oil PSI is at .6 at 800 RPM and 3.6 at 3000 and just gets to 5.0 or so at high RPM. Like I said the outside air temp does not have anythig to do with PSI. I can drive the car hard or easy and it makes no dif what the oil PSI does. I have talked to several Acura tec's with no soulition. Any body got any Ideas. Does the NSX have a oil PSI regulator and were is it? Is there a factory oil cooler. Yes the oil has been changed and it is 10 w30 Mobil 1 with factory oil filter. I have also changed the sending unit. Thanks for any info.

 

[Slingshot]

The NSX has a engine oil cooler above the oil filter. There is a relief valve in the oil pump housing that controls the psi. My guess is the relief valve is sticking because it is scored. Refer to the lubrication system on oil flow in the service manual 5-11 and 5-12. You should experience a minimum of 10 psi at idle and 50 psi at 3000 rpm or the oil pump and/or relief valve should be replaced or overhauled.

[This message has been edited by Slingshot (edited 08 September 2002).]

 

[DutchBlackNsx]

I have exactly the same problem. (in addition to the low readings at high rpm)
It is a known problem that the reliefvalve is getting scored. I think it is actualy in the faq.
I replaced the reliefvalve on mine (it's inside the oilpumphousing), and it didn't make any difference. It looked like new, but replaced it anyway.

I also replaced the second reliefvalve, which is in the oilcoolerhousing (this one keeps the oil high-up in the engine, after the engine gets switched off). I took it out the other day for inspection, and found the inside to look horrible scored and worn. I couldn't believe how it looked! I found my problem! Straight to the dealer, ordered a new one. Next day got it.......looked exactly the same...................(can't believe that Honda uses that).

There is also a TSB about the sensor and gauge. http://www.nsxprime.com/FAQ/Reference/tsb/91-008.htm
Though the VIN might be out of range, it always could be this.


Let me know if you find out.

Mich