Quote:

---

I have a 440 that usually runs with 30-35lbs of oil pressure at idle and anything above around 1500rpm the pressure goes right to 80lbs or more.

What's weird is in the last couple of days its now running at 80lbs at idle and 80lbs or a bit more at any rpm above that, hardly any difference in oil pressure across a range of rpm's. I am reading this on a mechanical gauge straight off the rear of the block. I hooked up a spare gauge and its giving me the same exact readings. Very weird.
Could this be an oil pump regulator? Any suggestions?
Thanks,
Wolfe

---

Take the bypass plug and spring out and see if the bypass valve will slide out of the pump cover easily, if it doesn't fix it. It is not unusual for debris to get into the valve and make it stick

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

Quote:

---

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

This doesn't make sense. If it was 35, of course it could have been open. Now that it's high, it could be plugged.

---

Quote:

---

Quote:

---

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

This doesn't make sense. If it was 35, of course it could have been open. Now that it's high, it could be plugged.

---

The only way that works is if the valve didn't close fully possibly due to a burr or something of that sort, otherwise low pressure won't open the valve because the spring pressure is constant... It was lifting @ 80 psi.... If the valve opens at 35 psi the pressure wouldn't rise above 35 psi unless the pump volume was so great it overcomes the flow capacity of the relief passage... Pressure rising typically indicates a place where oil was previously able to leak internally has become sealed... That could indicate a number of causes including plugged rocker feed, a spun bearing, a plugged chain oiler..

---

Quote:

---

Quote:

---

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

This doesn't make sense. If it was 35, of course it could have been open. Now that it's high, it could be plugged.

---

The only way that works is if the valve didn't close fully possibly due to a burr or something of that sort, otherwise low pressure won't open the valve because the spring pressure is constant... It was lifting @ 80 psi.... If the valve opens at 35 psi the pressure wouldn't rise above 35 psi unless the pump volume was so great it overcomes the flow capacity of the relief passage... Pressure rising typically indicates a place where oil was previously able to leak internally has become sealed... That could indicate a number of causes including plugged rocker feed, a spun bearing, a plugged chain oiler..

---

How about a piece of debris wedge into the valve and the pump channel keeping the valve locked closed, like it is when the motor is shut off

Quote:

---

Quote:

---

Quote:

---

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

This doesn't make sense. If it was 35, of course it could have been open. Now that it's high, it could be plugged.

---

The only way that works is if the valve didn't close fully possibly due to a burr or something of that sort, otherwise low pressure won't open the valve because the spring pressure is constant... It was lifting @ 80 psi.... If the valve opens at 35 psi the pressure wouldn't rise above 35 psi unless the pump volume was so great it overcomes the flow capacity of the relief passage... Pressure rising typically indicates a place where oil was previously able to leak internally has become sealed... That could indicate a number of causes including plugged rocker feed, a spun bearing, a plugged chain oiler..

---

How about a piece of debris wedge into the valve and the pump channel keeping the valve locked closed, like it is when the motor is shut off

---

Quote:

---

I'm thinking possible filter faiure as mentioned earlier.

---

Quote:

---

Quote:

---

Quote:

---

Quote:

---

If the oil pressure went from 35 to 80 at idle, it not the spring or relief valve. The relief was not open at 35 to begin with.

---

This doesn't make sense. If it was 35, of course it could have been open. Now that it's high, it could be plugged.

---

The only way that works is if the valve didn't close fully possibly due to a burr or something of that sort, otherwise low pressure won't open the valve because the spring pressure is constant... It was lifting @ 80 psi.... If the valve opens at 35 psi the pressure wouldn't rise above 35 psi unless the pump volume was so great it overcomes the flow capacity of the relief passage... Pressure rising typically indicates a place where oil was previously able to leak internally has become sealed... That could indicate a number of causes including plugged rocker feed, a spun bearing, a plugged chain oiler..

---

How about a piece of debris wedge into the valve and the pump channel keeping the valve locked closed, like it is when the motor is shut off

---