Hi everyone,
I need some advice related to engine oil temp and pressure.
First off my car is a '81 280zx, automatic, stock everything as far as I know, so everything is old, except I recently rebuilt the engine. (less than 4,000ks). (all I did was replace rings bearings gaskets and repaired head, and new water pump since the head had corroded and was leaking coolant into oil, didn't replace the thermostat as it seemed to work at the time)
Recently got radiator flushed but they had to cut like 3 tubes from the radiator and there is a bit of damage at the bottom of the radiator so I'd say it's about 80-90% good.
Anyway my engine oil seemed to get rather hot (middle of the gauge-90C?). When I pulled up to the lights in drive, at idle speed it couldn't make enough oil pressure and the red light would come on. It seemed ok in neutral as the revs were few hundred rpm higher, just enough to get it out of the danger zone. So I assumed the radiator was unable to cool the engine properly since the water temp was also up in the middle of its gauge (~90C) and trying to start the engine at this temperature was near impossible as the starter motor seemed to be useless next to such a hot block.
So I got the radiator flushed - massive difference engine runs at about 70C. But the oil still gets to 80C and pulling up to the lights yesterday the low oil pressure light still came on!
So whats happening, is the oil to hot and thus to thin to be pumped effectively?
-using 20/50W non-synthetic oil
This being said the ambient air temp was 37C in the shade and I put my thermometer in the sun it went off the scale (more than 55C). The car was in the sun the whole time I was driving.
I presume this isn't normal for a old z car?
Any suggestions much appreciated as I would really like to go the "slightly south cruise" this weekend. It has good oil pressure while driving so I'm wondering would it be ok to drive it a few hundred k's at highway speeds?
Thanks,
Kuy