Engine overheat?, Diagnose this for me! Options

[gts4]

Hey. I drive a 94 gts. Basically, there appears to be a small oil leak, and I had rad blow on me. I replaced it, but my temp gauge tends to redline after 45 min of driving. Sometimes, it stays high, then dips down to 40%. It goes up and down.

It seems to go up when I downshift and hold it at 4-5k rpm.


Other times, it just moves by itself. Any ideas? Thanks!

Update. Found an oil leak on the valve cover gasket. Will fix it this week. Will check the thermostat after the leak is fixed.

Edit: I'm having another issue. The celica won't turn over. After shampooing and pressure washing the engine yesterday, my celica would stall at a red light. I barely got it going again, but made it home. It was turning over and started after 3 tries. This morning, it turns over and chugs without starting. What's the issue? Did I flood anything? Should I check the distributor?
Solved the starting issue! Distributor was fine. Switched to iridium spark plugs. Starts better than a new car
Thanks everyone!

This post has been edited by gts4: Feb 9, 2012 - 12:35 PM

[bsamps4]

if the oil and coolant are mixing, then he'd have a blown head gasket and/or if there was coolant getting into any of the cylinders.

Oil and coolant do NOT always mix when a head gasket is blown. It depends where the breach in the head gasket lies. Premature breakages can cause these type of issues where driving the vehicle cools the engine, and sitting at stop lights burns it up. If you are revving your engine to make the temp gauge go down, then your headgasket is likely the culprit. There are SEVERAL symptoms that a bad head gasket can present.