Miketn12

Hello everybody, I have boxster with very low oil pressure at idle when the engine warm up. Engine cold idle it shows 90 psi then it goes way down and oil light on when warm up. I m think about install a mocal electric pump and pump the oil to the valve cover. Please give advice

GVA-SFO

I'm quite curious : How do you know the oil pressure of your Boxster ?????

Macster

GVA-SFO asked the right question.

When it comes to possible issues with oil pressure you have to be sure of the pressure.

The oil pressure sensor on the Boxster engine gets its pressure from an oil galley of one of the camshaft covers.

You need to confirm what the oil pressure really is and if too low then what might be the problem.

Is the oil level good? Is the oil reasonably fresh? Is the right oil in the engine? None of that 5w-20 stuff are any number of other "thin" oils. The oil pressure should be good with 0w-40 oil in engine.

Has any engine work been done? I'm thinking perhaps a camshaft cover has been off the engine and the sealing job at its installation could be suspect, that is an internal oil leak could account for the low oil pressure.

If the pressure truly is low. You need high confidence oil pressure numbers before you do anything else.

Miketn12

Thanks for the reply. This car had a blown head gasket because of a broken water pump. I repair the head replace the new head gaskets. The engine run smooth no noise no smoke but the oil pressure drop when it got hot I install a oil gauge When the engine hot the gauge needle drop down fast to 15 psi for a while then it go even lower to 5 psi then oil light on.

mikefocke

Also see JFP's reply to your issue on Pelican.

Miketn12

Engine oil is correct level and viscousity I will remove the cover again to check for leak as soon as temp gauge get to 180 degree the oil gauge needle start to drop almost like some pressure valve is open to release from 90psi to 15 and then to almost zero

Macster

The pressure relief valve in the pump. It opens at some high pressure to avoid over-pressurizing the oil filter housing and oil filter element.

Once warmed up the oil pressure relief value should not open except maybe at very high -- red line -- RPMs.

This pressure relief valve is pretty reliable and unless you tell me you have been at it, maybe replaced the oil pump, something like that, it is hard to believe it is the cause of the pressure drop. The valve is not completely beyond suspicion though.

The oil level is not dropping. The coolant level remains ok. This is a good indication there is no leakage of high pressure oil into the cooling system or oil leaking out of the engine.

It reads more like something is getting hot and opening up and letting the pressure drop but with no loss of oil.

This points to an internal oil leak. The oil leaks from a high pressure area to a low pressure area.

This could be the camshaft cover. Do you have all the bolts torqued down properly? Did you torque them in the right sequence?

As I think I may have touched upon earlier the camshaft cover sealing is critical. Critical that one uses the right sealer, puts the right amount on and in all the proper places, then carefully places the camshaft cover in place and follows the proper tightening/torque steps.

Miketn12

thank Macster. I removed cam shaft , lifters housing( valve tapet housing) for both heads inspected and found no problem. Reinstall and carefully reseal the cam cover and still have the same oil pressure problem. Is the a oil seal or oring in the head that i miss or bad oil pump? the pump put out 90 psi when cold so it coudn't be bad. Up until now i have remove both heads cam shaft 3 times to inspect. i m totally lost. Any advice appreciated.

Macster

Can't help you with the question about an o-ring or seal being missing. The time to ask that question is when you are assembling the head to be sure nothing is missed, left out, forgotten.

Oil pumps do not fail. Well, there are exceptions of course, but this doesn't read like a pump failure. More often an oil pump wears out and develops excessive clearance at the ends of the pump gears. This is an internal oil leak and results in lower pump output. I was always told to when I had an engine apart to replace the oil pump, but not before checking end clearances to ensure the new pump didn't have excessive clearances to begin with.

Let's see... Oil pressure starts out high, as expected, then falls way down when warmed up? I have not read the thread again to refresh my memory but if you are sure the oil pressure is truly low and the other camshaft cover has not been disturbed and thus doesn't (or is very unlikely to) have an internal leak that leaves the oil pressure relief valve. One possibilty is it opens under high oil pressure when the oil is cold but jams/remains open even as the oil warms up and of course the warm oil's oil pressure is drastically reduced.

Or it is jammed partially open enough that cold oil pressure is limited to 90psi but as the oil warms up and pressure falls the valve doesn't/can't close but remains open and thus the warm oil pressure falls realy low.

About all that I can offer then is you remove the oil pressure relief valve and examine it for any signs of the piston hanging up or the spring broken, etc.

I'd not reuse the pressure relief valve but replace it with a new one. If there is an updated part # be sure you get the updated part.

Schnell Gelb

There is an upgraded piston +spring _Search.