Just today noticed the oil pressure guage drop to around 1 at idle and the warning light came on. Pushing the rpms up and the pressure rises to the 5 at 4000rpms.

Checked the fluid level and added the 1/2 quart it was low. But it is still did the same thing as I came to a stop and reached idle.

What might I check next or is this a sign of a sure problem?

Thanks in Advance!

 

Jerry, you could have a faulty oil pressure sending unit or faulty gauge, or in the worst-case scenario, a bad oil pump. I would not drive the car until your verify the true systems oil pressure with a gauge. You will need to remove the sending unit and with the right plumbing install the gauge there.


Right pressure faulty unit or dash gauge.

Low-pressure, worn pump, pressure relief valve stuck or broken spring, bypass valve stuck or spring broken

Good luck
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

If your oil pressure really is low, one possible cause is that one of the plastic plugs at the rear of the cam shafts has come out. The S4 and later cams are shorter than previous ones, so plugs were put in the area that the longer cam's rear bearing would have occupied. The plastic can warp and come out, allowing oil to be freely pumped into the cam area. There's some information and pictures at:
<a href="http://ourworld.compuserve.com/homepages/nichols/tip578.htm" target="_blank">http://ourworld.compuserve.com/homepages/nichols/tip578.htm</a>
<a href="http://members.prestige.net/jpirtle/keepers/engine/low_oil_press.txt" target="_blank">http://members.prestige.net/jpirtle/keepers/engine/low_oil_press.txt</a>
<a href="http://members.rennlist.com/v1uhoh/nasty.htm" target="_blank">http://members.rennlist.com/v1uhoh/nasty.htm</a>

 

I have an oil leak that I thought was due to the camshaft plugs so I bet or hope that is the problem of the low oil pressure.

Thanks Steve and Mike

 

If one of those plastic cam hole plugs did come loose, it wouldn't cause an oil leak. At least not one that you'd see. The oil would still be under the valve cover. There are different plastic seals at the ends of the valve covers that may be the source of your leak, but one of those leaking wouldn't result in low oil pressure. If you're pulling the valve cover(s) off to fix the leak, you'll easily see if the plastic cam plugs are still in position.

 

Just giving you an update. My friend had a sending unit so I installed it but unfortunately my guage still reads low on idle.

I had to remove the oil filter to get the unit out but the timing was good since I needed to change it anyway.

Next step is to hook up a pressure guage to see what it reads.

 

The 928 has two seperate oil pressure monitoring systems. The oil pressure gauge and the oil pressure warning light have seperate sensors.

If only one shows low oil pressure (e.g., gauge at zero, but no warning light), odds are that the oil pressure is OK and the gauge is lying.

If you get both a low gauge reading AND a wrning light, the oil pressure IS low. Don't bother with hope that it may be a bad sending unit - the odds on that are real long!

The usual possible causes apply - cam oil hole plugs (no relationship to the cam bore plugs that seal the outside holes), stuck oil pressure relief valve, bad pump, etc.

 

Jerry,

Check out Sab's post on the "Drain plug leaking" topic. Might be related to your situation?

Greg

 

My friend's oil pressure guage has not been available yet so I am still looking at possibilities assuming I do have low oil pressure. I know it is not the sending unit as I have tried a new one.

If I understand correctly, I should check 32 and 33, pressure relief valve and spring. Also, 28 and 29 bypass valve and spring - I dont have the valve chatter so could this be less likely?

Any special instructions for extracting and checking 32 and 33?

 

I have just replaced these on mine as I was pretty much there when I did the timing belt. 32 is a real bitch to get back in, the spring pressure is STRONG and there is very little room down there.

To remove you'll need to drop the oil cooler pipes.

I still think as someone else mentioned it is those CAM plug as that would give you the low pressure at idle.

Chris

 

Here is the latest. Put a guage on my Shark and the pressure read 1.5 Bar at idle and of course 5 when the rpms went up.

The sending unit says the warning comes on at .5 Bar +/- .15 so I should be okay. I put a new sending unit on it just in case the other was faulty.

I guess I dont have a problem even though I have read many people have 3 bar at idle.

Any thoughts?

 

depending on the type of oil I use, my gauge also reads 1.5 Bar at idle (operating temp). Running Castrol GTX 10w 40 idle shows 1.5, 10w 50 reads 2.0.
I will try Mobil 1 next time.
regards,
Sab.

 

Tomorrow, I am going to put some 15w 50 in and see if makes a difference.