View Full Version : test drive and oil pressure

05-01-2012, 03:49 PM
Today I finally took the TR6 out for a test drive after rebuilding the engine (with a lot of help from the forum.)

The oil pressure was about 65-70 psi at idle in the shop. It came up to about 80 while driving. (2200-2500 rpm)about 6 miles up the road I noticed the oil pressure was droping.
It came down to 55-60 psi. I turned around and brought the car home. The pressure was then 45-50psi at idle.

I did not change the oil pump on the rebuild. Maybe should have.

I am sure that the slot on the dist fit properly on the oil pump dog. It slid in place with no pressure.

Any ideas?

05-01-2012, 04:01 PM
Strictly speaking... not being a TR6 guy. but those numbers sound healthy. not so sure about the sudden drop though.

05-01-2012, 04:32 PM
I think you'd need about 20 minutes of driving for the oil to get hot.. Once it's hot, I don't think you'd have OP that high at idle speed.

05-01-2012, 05:17 PM
I think I remember the oil pressure being higher that that before I had the problem and rebuilt the engine. But, then again, my memory is not too trustworthy any

I am going to ride the car locally for a few days and see what happens.

I noticed one other thing. The temp gage did not come up to what I would call normal operating temp. The hand stayed very near the "C" mark. I suspected the thermosthat so I changed it and had the same thing.

All of the other gauges are reading normal. I now suspect that the gauge might be bad. I might pick up an aftermarket gauge and see what it does.


05-01-2012, 08:19 PM
Anyone see any problems driving the car for a few miles and seeing if the op drops anymore? I don't want to damage the engine but I don't what to check next.

any and all help appreciated.

05-01-2012, 08:42 PM
Certainly not with those kind of numbers. The old rule of thumb is at least 10 psi for every 1000 rpm; as long as you stay above that there should be no chance for any damage.

Personally, I think all you saw was the oil warming up, but I could be wrong.

05-02-2012, 08:27 AM
I vote drive it! As long as it finally reaches a stable pressure above 50psi while driving and 15psi idling you will not damage anything. I don't think I have ever had a car with idle pressure as high as yours!


05-02-2012, 10:32 AM
+ 1 on Randall and John and folks, I think you are fine. Just keep an eye on it for now. I have come to believe that we all get a bit to fixated on being slightly under brand new engine oil pressure - as long as it is enough it is enough.

05-02-2012, 07:37 PM
Thanks guys. Thanks for all the help on the rebuild and the advice.