The oil pressure on my EA81 is too high. It hovers around 75PSI (top of the gauge in the red area) when running at around 2500RPM. The front seal and possibly the distributor gasket and I think oil pump are all leaking a small amount. Collectively it loses about 1/2 quart in about 400-800 miles. This is heavy stop and go traffic use. What are the most obvious things to check and how do I check them? I was told it could possibly be the PCV valve, but I replaced that and if it eased the oil pressure at all it's been barely noticeable. So whats to check next?

Is this an aftermarket gauge?

If its a factory one, dont trust it.

What oil do you use?

The PCV system can cause seals to leak if it's plugged. Check all of the hoses for it, making sure they are clean, also check where the PCV valve goes into the intake for gunk there.

 

As for the high oil pressure, the only thing I can think of is a faulty pressure relief valve in the oil pump. Either the spring is of a way high spring rate, or there's something keeping the valve seated, IE: gunk, dirt.

sure sounds like an oil pump problem, l would be looking at this.

The gauge I am reading is the factory in dash one, so those are inaccurate?

If it does not go down when fully warm, the pressure relief isnt working. For ease of your repair, I would hope its a bad guage read (stuck reading cold pumps pressure? A friends loyale wagon did this.)

High oil pressure will not cause seals such as the front seal and around the distributor shaft to leak. These are not really pressure lubricated points. The seals are either just worn (likely with front seal) or you have internal gas pressure from a misfunctioning PCV system or very excessive blowby. Or both.

If it does not go down when fully warm, the pressure relief isnt working. For ease of your repair, I would hope its a bad guage read (stuck reading cold pumps pressure? A friends loyale wagon did this.)

I would expect the pressure relief valve to show its effects at startup where the pressure is more likely to exceed its relief value, rather than once the oil has warmed. The pressure should drop naturally as the oil temp goes up and the viscosity decreases.

 

The dash gauge, like all dash gauges can be somewhat inaccurate. The sender unit can give some truly odd values, especially if damaged.

 

Mine shows 75 PSI at idle while cold. The first time I saw this reading (the car was new to me) I cleaned and reinstalled the pressure relief valve, but it made no difference.

It goes down when its idling but at 2K its back up to 70-75, so if the pressure relief vlave is bad then what have I got to do? BTW I have 2 EA81 parts cars at my disposal and one has a low miles engine but I prefer to keep that one whole.

The pressure relief valve shouldn't do anything once the engine is warm anyway.

Are you sure you're using the correct oil viscosity?

 

Most likely, id say your pressure sender is bung, you should temporarily install a mechanical gauge and see how that reads.

I use 10W30 isn't that correct for the PNW?