Honestly, I never knew there was an oil pressure regulator; just a sensor. The oil gauge on the dash is showing high pressure (60 - 80). Is the regulator a failure item?

I guess the easy test would be to change the oil and filter to see if the pressure goes down, but the oil has less than 1500 miles on it since the last change and I have always used the same Delco PF filter. I could also throw in a bottle of Marvels Mystery oil and see what happens to the pressure after an oil change.

It appears that you have to pull the timing cover to get it (oil pressure regulator) out of the oil filter bracket. Heck, might as well change the timing chain and tensioner too.

Words?

The oil pressure regulator IS mounted on the timing chain cover, but you do not have to remove the cover to get to it. All the regulator is, is a steel rod that has a spring behind it, that sits in the timing chain cover and the oil filter adapter.


So all you would have to do is, remove the oil filter, then remove the 4 bolts on the filter adapter. You will see that the oil filter adapter will (should) get pushed out a bit, that is from the pressure of the spring on the back of the steel rod.


Unless the rod is stuck in place, that is the only thing I could see that would cause high pressure in the regulator anyhow. If the spring broke, your pressure would drop or even go to 0.

Reason I know all this is that I recently changed my engine and did a bit of discovery (not by choice) while I was doing it.

i could se 60psi being normal, and ive hit 80 before in mine, are you sure its the regulator, did you use the correct weight oil, did u use synthetic or regular? etc etc and supposedly autozone was carrying fake acdelco filters a while ago, i dunno if they still are but thats something to watch out for. i personally use the supertech full syn 10w30 in all my cars with a supertech filter. $14ish for a full syn oil change, u cant beat that, decent quality stuff too

is it possible for that spring to become weak and lower oil pressure? Mine is like 35psi, and although in the safe zone, I like my oil pressure higher. It makes me feel more secure about my engine, although i bet the lower oil pressure is from my bottom end being blown [unconfirmed].

[quote="MartyC"]Honestly, I never knew there was an oil pressure regulator; just a sensor. The oil gauge on the dash is showing high pressure (60 - 80). Is the regulator a failure item?

I guess the easy test would be to change the oil and filter to see if the pressure goes down, but the oil has less than 1500 miles on it since the last change and I have always used the same Delco PF filter. I could also throw in a bottle of Marvels Mystery oil and see what happens to the pressure after an oil change.

It appears that you have to pull the timing cover to get it (oil pressure regulator) out of the oil filter bracket. Heck, might as well change the timing chain and tensioner too.

Does the pressure read consistantly high or does it spike occassionally? Not sure about the '91 but earlier years had a fairly common occurance of pressure sender failure. The usual mode of failure was the pressure will read normally and randomly spike high for some time and return to normal, sometimes going full scale.

Yes. It does spike some times. I should probably change the sender first. When my truck got to this mileage, I changed most of the sensors. I guess the Bonne' is due.

You don't have to pull the timing cover to get to the pressure relief valve (regulator). As stated before, you remove the oil filter adapter, and it'* right there. The oil pressure sending unit is on the same adapter, so you have to disconnect the wiring connector, then 4 bolts and it'* off.

Getting to it can be done from underneath, or pull the right front tire & plastic fender liner. Removing the belt helps if you go from fenderwell.

Senders fail so often I just keep a spare around. Is easy to change and the place I always start. Regulators rarely fail and when they do, they usually stick open, not closed.

OSG, I'd assume normal wear on the motor internals is the reason your pressure is there.

If you are going to change the sender, just unscrew the old one and install the new one, no need to unbolt the filter adapter.