Low Oil Pressure At Idle - 986 Forum - The Community for Porsche Boxster & Cayman Owners

gabedrummin · 01-10-2018, 06:15 AM

Low Oil Pressure At Idle ? Is there any way to increase idle oil pressure ?Can the gears in the oil pump be replaced. Is the only recourse to replace the motor.Oil pressure off idle is fine . Only when stopped with hot motor will oil light blink.Motor runs great.No noise.

Brian in Tucson · 01-10-2018, 06:22 AM

Quote:

Originally Posted by gabedrummin

Low Oil Pressure At Idle ? Is there any way to increase idle oil pressure ?Can the gears in the oil pump be replaced. Is the only recourse to replace the motor.Oil pressure off idle is fine . Only when stopped with hot motor will oil light blink.Motor runs great.No noise.

How many miles on the engine? Oil pumps almost never wear out. Bearings do and there are a whole lot of bearings in these engines. And past experience on other engines has taught me that low oil pressure at idle indicates a worn engine.

Sorry. I think you need a replacement. Or just live with the low oil pressure for a while--it could last for years.

gabedrummin · 01-10-2018, 07:11 AM

I agree with the wear, so. Aluminium oil pump housing running hardened steel gears. Low pressure is only at idle as soon as rpm increase so dose pressure. So why couldn't it
be the pump walls are slightly wore. At low rpm pressure is lost between gears and pump wall ?I cant believe no one has tried to re build or replace the pump . If it had low pressure across the entire rpm range then yes rod and main bearings shot.Or knocking rods .

JFP in PA · 01-10-2018, 07:31 AM

Quote:

Originally Posted by Brian in Tucson

How many miles on the engine? Oil pumps almost never wear out. Bearings do and there are a whole lot of bearings in these engines. And past experience on other engines has taught me that low oil pressure at idle indicates a worn engine.

Sorry. I think you need a replacement. Or just live with the low oil pressure for a while--it could last for years.

Can't agree. These engine's are known for weak or weakening oil pump oil pressure relief valve springs, Porsche even released an update kit with a spring and updated piston to address the problem, retail cost around $20 and 5 min. DIY to change.

Before thinking about replacement engines, I would:

1. First check the actual oil pressure with a known gauge, you wouldn't be the first with a bad sender.
2. Get the updated parts and install them.

Gilles · 01-10-2018, 08:57 AM

Gabe, are you using 0-40W oil? since you live in Houston you may want to try 5-40W next time to see if it helps with the low pressure at idle..?

gabedrummin · 01-10-2018, 09:51 AM

Thank you guys I am using 5w40 royal purple.Porsche was not happy with my chose.I have seen the updated spring and plunger . My only concern is the new piston has a chamfer on one end . I would assume the chamfer edge face down.but dont know for sure? You guys and this forum rock..!

AZ986S · 01-11-2018, 02:02 AM

I just had this problem last summer. See post below. Not saying that is your problem and I'm sure there are other things that the cause low oil pressure like worn bearings etc...

Accusump install

For me, it ended up being a valve spring that broke, taking out the hydraulic lifter and valve keeper debris being swallowed through the bank 2 scavenge pump and main oil pump. This in turn damaged the oil pump gears and aluminum pump cassette walls. So the moral of the story for me was that I tried different oils, installed the upgraded pressure relief piston and spring etc... to no avail, until I dropped the oil sump to discover the debris. The oil pump and cassette are about $500 and probably a PIA to replace with the engine in...

gabedrummin · 01-11-2018, 09:31 AM

First thing I did when the indicator light blinked at me was drop the pan.I thought the pick up was clogged . No clog or debris found. I added a 2 quart sump and changed from 0-w40 to 5w-40 . Maybe the thicker oil is hard to pick up at low RPM ?I ordered the spring and piston, a new sending unit for a 996 ,and a separate oil pressure gauge .I will put the bypass and gauge in soon .It would take little wear to lose oil pressure between the oil pump gears and walls of the pump at idle.I wonder why you cant get the gears.My 72 AMC jeep's 401 V8 had the oil pump in the timing chain cover .And a rebuild kit was available.

911monty · 01-11-2018, 09:39 AM

Have you checked vacuum at the oil cap. This could be caused by a failing AOS. According to Dr. Raby there are two failure modes for the AOS. It can fail in a condition that pulls oil from the oil pump pickup, sometimes accompanied by a high pitch squeal from main seal(s). Since max vacuum occurs at idle it's a possibility.

See discussion attached Looks like AOS, but engine WOES

gabedrummin · 01-11-2018, 02:36 PM

Cap can be removed easily ,when removed car runs bad .Put cap back runs ok again.

Anker · 01-11-2018, 02:47 PM

The oil pump pressure relief valve can be damaged or have debris stuck in it. That would be consistent with the symptoms. When the oil flow is low the leakage through the valve would be significant enough to lower the pressure. At higher RPM, and thus higher flow rates, the leakage would be insignificant enough to not affect the pressure.

Quadcammer · 01-12-2018, 04:11 AM

amazing this has to be raised given the seemingly decent technical knowledge here, but a 5w-40 and a 0w-40 are the same weight when the car is at operating temperature (setting aside slight cst differences between brands).

The number before the w is the COLD viscosity.

gabedrummin · 01-19-2018, 07:02 AM

Can the bypass spring be replaced with oil in motor ? Thank you all so very much..!

911monty · 01-19-2018, 07:34 AM

Quote:

Originally Posted by gabedrummin

Can the bypass spring be replaced with oil in motor ? Thank you all so very much..!

Yes. There is only a few ounces that will drain.

gabedrummin · 01-22-2018, 10:46 AM

A Porsche mechanic asks if I have replaced my I.M.S. bearing I say no . He says that can cause low oil pressure at idle. How is that possible when the bearing is not fed oil from the pump ?

JFP in PA · 01-22-2018, 11:06 AM

Quote:

Originally Posted by gabedrummin

A Porsche mechanic asks if I have replaced my I.M.S. bearing I say no . He says that can cause low oil pressure at idle. How is that possible when the bearing is no fed oil from the pump ?

You need a new mechanic.........................

Smallblock454 · 01-22-2018, 02:31 PM

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paulofto · 01-23-2018, 06:48 AM

Quote:

Originally Posted by gabedrummin

A Porsche mechanic asks if I have replaced my I.M.S. bearing I say no . He says that can cause low oil pressure at idle. How is that possible when the bearing is not fed oil from the pump ?

Really? Once again the IMS is blamed for everything from a burnt out tail light to a flat tire. I think at some point climate change will be blamed on a bad IMS.

gabedrummin · 02-06-2018, 03:00 PM

Put in the updated spring and piston .Put a mechanical gauge on it today 10 psi when motor is hot with 5w-40 oil. What would be the thickest oil I could run .Live in the south west.

boxfix · 02-06-2018, 03:49 PM

I use 15w-50 Mobil 1 synthetic in my 2003 in the Los Angeles area. I buy from Wal-Mart ordered from their web site delivered to my door. Free 2 day shipping on orders of $50 or more. 2 5 quart bottles will get you free shipping. You need 8.5 quarts so you need to buy 2

This is what you should use in a warm climate.