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GT6 GT6 Oil Pressure

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dklawson

dklawson

Yoda
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I tried "search" on the assumption I'd find old threads on 6-cylinder oil pressure but I didn't locate any. Forgive me if this has been beaten to death and I simply missed an old thread.

On the way home from a show last month our GT6 started running hot to the point that it thinned the oil down enough to trip the pressure switch at idle.

I tested the switch and found it changed state at 22-25 PSI. Further checking showed that the factory switch was supposed to change state at about 5 PSI.

I have since installed a new/correct pressure switch, flushed the radiator, fitted an oil pressure gauge, and done a bit of additional work to improve the cooling situation.

On other cars/engines I've worked with I've been told that a good rule of thumb is for the engine to have 10 PSI of oil pressure for every 1000 RPM. Does that hold true for the 6-cylinder TR engines? My hot idle oil pressure at 1000 RPM is right at 25 PSI which would be acceptable on other cars I've had. Is it OK with the GT6? (Cold oil pressure is very good... near 75 PSI with a fast idle near 2000 RPM).
 
Those pressures you are getting seem to be okay. I would leave the higher pressure switch installed. If it kicks at 22 PSI you can shut down with a safety cushion. 5 PSI at highway speed is a boat anchor in the making.

Jim
 
dklawson said:
...I have since installed a new/correct pressure switch, flushed the radiator, fitted an oil pressure gauge, and done a bit of additional work to improve the cooling situation....
Click to expand...
I hope you also flushed the block! (I know, y'all are probably tired of me saying it, but it's amazing how much gunk accumulates in those blocks!)

Also, what sort of pressure are you seeing how "hot" and at road speed? Generally, anywhere from 40-60 is considered normal. And are you using 20W-50?
 
I will let you know the road speed pressure next time I drive the car. At this point all I can say is that after prolonged idling at 1000 RPM and the temperature approaching 195oF, the pressure holds right around 25 PSI. If I rev the engine at that point the pressure builds very quickly and easily exceeds 40 PSI at 3000 RPM. I am running 20W50.

When I flushed the radiator I did flush the block as well. One of my acquaintances in the U.K. mentioned something I am really not comfortable doing. He suggested flushing the block using drain cleaner. Any comments on that?
 
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