Oil pressure question

[Michael Oritt]

When I start my car up my OP is about 65 psi on the guage with revs above 2000 and about 40 psi at idle. However after the engine and oil come up to temperature the OP drops to about 55 psi at revs above 2500 and falls off to about 40 psi with revs of 1500 and only about 20 psi at idle.

Do I have an incipient problem? Last year I pulled out the relief valve spring and shimmed it about 1/4" which increased OP about 5 psi across the board but I wonder if it is time to replace the spring with a new one and/or lap in the valve. Or is my oil pump not being all it should be?

The engine was rebuilt about 50K miles ago but consumes virtually no oil, does not smoke and runs strong. I run 10W/50 synthetic oil.

Am I worrying unnecessarily?

 

[Keoke]

Yeah I think so Michael with the lighter oil, the pressure warm at idle is not the greatest but ok for now. I would look into the rocker shaft and make sure it is not worn enough to lower the oil pressure. There may be a bearing replacement down the road a bit though.--Fwiw---Keoke

 

[healeyguy]

MO, if you did'nt take those trips to Texas via Canada then the motor might last longer. I hear that the Marlyand State Police have an APB out for a long low red car with a white top that they have not been able to catch yet. I agree that the rocker assembly is beginning to wear, but the PSI you have is within the limits of acceptable.

 

[Michael Oritt]

I liked the advice that I got over on the Healey autox list much better--everyone there said I was okay and just needed to get a life or buy something else on which to obsess. Nevertheless I will pull my valve cover and look at the rockers though last time I checked I did not see any excess oil.

 

[shorn]

I don't think you have much to worry about. If OP dropped to 10-15 at idle, then I would start looking. Your numbers, especially with synthetic oil, seems normal for an engine with your miles.

 

[mbrooks]

Hi Michael,

A few weeks ago I had some work done by a mechanic here in Milan Italy. He did some good work, but put a modern synthetic oil in the engine [he could not tell me exactly what grade]and ATM in the transmission. Before the work I had old fashioned 20-50 in the engine and 90 weight gearbox oil in the transmission. Just last week he put the correct fluids back in. The modern synthetic oil in the engine had dropped the hot tick-over oil pressure to almost nothing. Putting the 20-50 back in, I get an absolute minimum of 20psi at hot tickover.

If Dave Russell is reading this, I can also report that the 90 weight gear oil has completely cured the O/D drop out that I was getting with the ATF.

Just shows that oil viscosity counts for a lot with our cars.

Rgds

Mike Brooks