95'chevy truck overheating?

If there was a gasket leak wouldn’t the engine temp gauge be up 250 260 all the time? The temp gauge goes up then goes down up & down.

The engine can have an intake manifold gasket leak and not overheat. But it can result in coolant entering the oil pan. The way you describe the temp bouncing up and down might point to a problem with air trapped in the cooling system. And to eliminate if that’s the condition, try this.

Get the engine up to operating temperature, and with the engine idling, slightly loosen the upper radiator hose clamp. Take a flat bladed screwdriver and insert it between the upper radiator hose and the radiator hose neck. Allow the engine to idle until all the air is purged out of the cooling system and then retighten the hose clamp. Check the coolant level.

Tester

Replace the thermostat.

Thanks I’ll try that.

I replaced the thermostat, rad, & temp sensor, no good then thinking maybe it was a gasket leak I put in gasket sealer barr’s this worked on my subaru, now I think I may have to flush this stuff out & AHHHHHHH1 this thing is driving me nuts! I never had this problem with my old truck! Ah modern technology.

I was told by a mechanic that they use a vacum type pump to draw the air out of the coolant system, ever heard of that?