cyman73

Hello all,

I searched for issues with the oil pressure gauge but I still have a few questions.

I just purchased my stock 1987 GT with ONLY 37K miles. My father-in-law owned it before me so I trust the miles.

When doing 75 mph on the highway I notice the oil pressure at the bottom of the NORMAL range. It picks up and moves one to one 1/2 ticks then drops down again.

I changed the oil to 10W30 Mobil 1. What is the recommended oil specification?

Can I possibly have worn bearings? Bad oil pump? Oil sending unit?

Thanks to all.

settled4automatic

i'm no expert, but people will say to get a mechanical gauge and see what the reading ACTUALLY is. that will help diagnose your problem a little further.

88GT40

with those kind of miles i think you can rule out bad bearings for sure, but with the age of those guges and sending unit, they are not trust worthy, get a mechanical oil pressure guage and install it then you will know for sure if you have a problem or not.
by the way
5w-30=wintertime
10w-30=summertime
usually becuse it is easier for it to turn over in the winter if the oil is lighter, some people go as far as yo use 0w-30 but i have some miles so i started using 10w-40