'92 camry running hot (sometimes)

[Hot Welder]

I have a 92 camry w/ 22e motor. in the spring changed the radiator, changed the thermostat and the rad. cap. Checked the fans (ok) when its running hot the bottom hose is cool to the touch, top hose is HOT. If i drive for a while longer the temp suddenly drops to the normal range. The cars runs fine during this period. My thought is the water pump might be going bad. Anyway to quickly check the pump operation?

[DFBonnett]

Sounds like the new thermostat may be defective. What brand is it?
FWIW
YMMV

[Mike Gerber]

It's also possible that when you changed the thermostat and radiator, you didn't properly bleed all the air out of the cooling system. Try raising the front end just slightly; facing forward in a slightly inclined driveway should be enough. Then, with a cold engine, remove the radiator cap and start the car. Let it warm up completely this way. It may take up to 45 minutes to get it warm this way. Watch the radiator opening where the cap normally goes and see if you notice bubbles periodically coming out. After about 45 minutes put the cap on and take it for a ride. See if that solves your problem. If it doesn't, I would agree with replacing the thermostat again. This time make sure you use a Toyota OEM thermostat.

Mike