QuestionI have a 1966 TR4A IRS which I have owned for 8 years. There is approx. 5,500 miles on a rebuilt motor. My question is about proper oil pressure. I run non-synthetic 15W-40. The hot oil pressures are as follows:
idle = 52 psi
1,000 RPM = 53
1,500 = 60
2,000 = 68
2,500 = 65
3,000 = 70
3,500 = 78
4,000 = 85
4,500 = 90
The driver's handbook states the oil pressure relief valve is set to control the pressure at 65-75 psi at 2,000 RPM and at normal operating temp.
So I have two questions:
1. is oil pressure relief valve intended to maintain the 65-75 psi even at higher RPM's?
2. when engine is cold, oil pressure will climb dramatically with RPM (i.e. 90+ psi at 2,500). Is that a concern or is pressure relief valve malfunctioning? Will such high pressures result in engine oil leaks?
Last question...what is your opinion on synthetic motor oils (Mobil One) in these older engines?
Thanks
Bob
AnswerHi Bob,
Yes, your oil pressure is higher than normal. First you need to get another gauge to check the readings against to see first that the high pressure is what you are getting and not just a faulty gauge. The fact that it climbs steady with RPM (if the gauge is correct) is an indication the pressure regulator valve is not functioning. You do need to correct it.
I have no experience with Mobil One, or any of the synthetic oils.
Howard
