Unusual Oil Pressure

[olddog]

Originally Posted by FatBoy

Thank you for the input. However, the gauge responds emmidiately to engine revs. so I don't feel that it or the sender is the cause of the anomaly.

Could the pressure relief valve be causing this?

Paul

If there is an intermittent problem with the gauge shifting its reading, it will still respond to the engine rev. Just because is responds to a pressure change, it doesn't mean it is functioning perfectly.

Certainly a PRV issue could cause a pressure change, but before I tore into my engine, I would make sure there was a real pressure change. The very first step is to verify that the oil pressure is indeed changing, as your gauge indicates. Or you can be like my brother n law. He replaced the engine in his wife's car, just to find out it had an empty gas tank.

I learned a long time ago to assume nothing. It could be many things. You have to start somewhere and prove what is or is not. In your case, I would start by proving that the pressure gauge in the car is correct or it is not correct. Then move forward. But if you are looking for an excuse to tear into the engine don't let me stop you.

[FatBoy]

The oil pressure gauge, along with all the others, is a Kirkham/Speedhut unit.

I've dropped the oil pan and taken off the oil pump. The pressure relief plunger initially felt as though it was jammed, but it moved freely enough now after spraying some cleaner in there and working it up and down a few times.

However, for the price of a new 57HV pump, I'm tempted to just fit a new one.

There was nothing inside the oil pan that wasn't supposed to be there, so I'm reasonably happy that there isn't something seriously amiss elsewhere in the engine.

Many thanks for the input and advice.

Paul

[olddog]

Originally Posted by FatBoy

I've dropped the oil pan and taken off the oil pump. The pressure relief plunger initially felt as though it was jammed, but it moved freely enough now after spraying some cleaner in there and working it up and down a few times.

Was it jammed or not? That is the question. Now it moves freely. Are you sure it did not initially move as freely. Unless you can be certain here, you really have nothing at this point. If you put it back in and the pressure still does funny things, you are still going to suspect the pump or PRV. Again I would advise you to verify the pressure with a mechanical gauge.

Originally Posted by FatBoy

However, for the price of a new 57HV pump, I'm tempted to just fit a new one.

If you change out the pump and you still have funny pressure readings, at least you will know it isn't the pump.

Originally Posted by FatBoy

There was nothing inside the oil pan that wasn't supposed to be there, so I'm reasonably happy that there isn't something seriously amiss elsewhere in the engine.

Make certain there is noting on the oil pump screen and nothing hidden behind a trap door that might come out and cover the screen. Also verify the pump is not too close to the bottom of the pan. While you have it apart check everything you can think of that might cause a problem.

Good luck.

[FatBoy]

Thank you. All sound advice.

The engine has run for over 25,000 miles with solid and stable oil pressure, so there is no reason to suspect that the pickup is too close to the bottom of the pan.

I'll cut open the filter to see if there is anything in there. What is the recommended filter for these engines? Ferrari owners like Baldwin filters, but I've not read too much on here about filter preferences for our cars.

Paul

[blykins]

Wix 51515R.

[olddog]

Originally Posted by FatBoy

The engine has run for over 25,000 miles with solid and stable oil pressure, so there is no reason to suspect that the pickup is too close to the bottom of the pan.

Unless the pan bumped something and is now slightly bent upwards a tad, I tend to agree. While you have access to it, check it anyway. I trust nothing anymore. Paranoia maybe. I been bit too many times by using sound logic and not verifying everything.