At cold start I see 60psi, then 30 until the car warms up.

When fully warm the oil pressure reads

Idle 4-5 psi
2000rpm 25 psi
3000rpm 45 psi

Ordered an o-ring for the front housing, and replaced it, but there were no signs of the o-ring being the problem. Assembled with rtv gasket maker.

Still no change in oil pressure. However upon doing this I noticed that there was oil pooling on top of the engine under neath where the fuel rail is, just above where the lower intake manifold bolts to the block, white arrow in the pitcures. I removed the upper intake manifold to check the oil metering lines. these lines have about 3000 miles on them and there are no signs of cracks, but perhaps this is where the problem lies. Has anyone had a problem with new nylon lines, is there anyone that sells a copper or steel metering line set? Where else could the oil be coming from?

I plan on replacing these lines and while I'm at it replacing the oil pump as well. All signs indicate the oil pump is fine, it will get to about 55-60psi around 4500rpm, but also I want to eliminate it as a potential problem.

frustration

 

Could very well just be your sender or gauge. You should buy a manual oil pressure gauge, hook it up to verify.

Other than that, you should stop driving it if you really think you are getting 4-5psi at idle. Great way to spin a bearing.

 

Replacing the OMP lines, while a good idea, will not fix your oil pressure problem.

replacing your oil pump is always a good idea. Might as well buy a TII oil pump, its a direct bolt on and doesn't cost much more. Nice to have the added safety of the TII oil pressure... you could mod your oil regulators as well. Up the ACTUAL pressure of your system.... All you need is access to a shop press, a spark plug socket, and a couple small washers.

 

same thing happened on my old s4. just think of 4 or 5 psi as 30 and 30 as around 60.

i dont trust the stock sender and gauge. they break and give false readings all the damned time.

 

My 87 turbo II has the same problem. I was told the car has 4 check valves and that was most likely my problem! One of them is stuck or not functioning properly. Again mine has the same reading as yours. Low pressure at idle and 30lbs while driving. Does your model have them and have you checked them?

 

I assume you are using an aftermarket gauge to test the oil pressure? If not, then you need to as the stock senders are old and often cause false readings.

There is really only one other option if you have already properly replaced the front cover o-ring and you are testing with a mechanical gauge: eccentric shaft oil bypass. It's located behind the front eccentric bolt and allows oil pressure to bypass the rotor oil jets when the car is cold to speed warmup. Failure will result in the exact symptoms you are experiencing.

The fix is to replace the bypass, or install a thermal pellet in it's place.

 

Not familiar with the "4 check valves" you mentioned can you elaborate? I know there is the spring check valve located under the oil pump in the front cover...and there is another bypass valve near the back of the block above the oil pan...

Sorry I should have mentioned the following:

This is an 88 10th anniversary model. the car/engine has 90000 miles on it just started showing these low oil pressures one day a while ago.
I have put in a billet replacement from mazdatrix in place of the thermal pellet in the front of the eccentric shaft.
I am getting the pressure readings from an aftermarket mechanical gauge, the stock gauge was also giving me the same readings.

 

Problems with the oil injection system (pump or lines) will not adversely affect the oil pressure that drastically.


-Ted