grand prix oiil pressure sender

You might want to put a real gauge on it and see what the pressure actually is. It's possible that the pressure relief valve is shot. Or the engine is worn out.

Make that "this did not do it last summer". Are you using exactly the same oil? Have you checked the ground circuits?

On my 1994 Trans Sport the guage would intermittently pin itself to full scale - usually under accelleration. At idle it would usually be at a believeable position, but I'd go to pull away and the oil pressure would either climb or spike. Put in neutral and rev the engine, the oil pressure behaved "normally"

The problem was a bad ground wire that bolts to the block at the front/bottom of the engine. Under accelleration, the wire "stretched" and lost contact.

The problem started in the fall, but had nothing to do with temperature or season. It worked just fine all summer. (last summer). Didn't work THIS summer untill I fixed it.

It's not the relief valve, because it wouldn't build up pressure, it may be a short in the ground wire