overheating help please!!!

[firemedicsafd]

I have an 88' blazer with a new tstat, hoses, and cap. i bypassed the heater core because of a leak in the cab and water is moving in the rad while she is running. I STILL get overheating during first warm-up, she will go all the way up to 250 deg, then she will drop to normal and stay there. I know the temp is right cause i have a computer hooked up while reading the guage. The wtaer level is full cold and hot with coolant in the recovery tank. Sombody PLEASE help me!

 

[chevyuser74]

radiator plugged?

 

[trikstark5]

Sounds like you have a bad thermostat. Where did you purchase the t-stat from? If you read in other posts, you see that other members have had the same problem and the thermostat ended up being the problem.

You check the t-stat by using a pot of water and thermometer. Place the t-stat in the pot of water. Heat the water up and monitor the thermometer as to when the thermostat opens up.

 

[firemedicsafd]

New tstat was bought from napa..stant model. I did the hot water test and both the original one and the new one opened up at 195 deg like they stated. I even made sure it was installed correct way( pellet toward motor)

I cant tell if the rad is plugged down from the top but when the truck starts and runs...water is moving near the cap.


Now what?

 

[BIOHZDK5]

Water Pump: Check the weep hole on the bottom of the WP. could be just about to give up. Could be moving fluid just not enough!
Fluid level: I know this is a silly one but can't tell you how many times I have scratched my head on a problem when the obvious solution was to fill it up to the correct the fluid level. I make the assumption that "sure its got fluid in it!"
Only other thing to address is you have a blockage somewhere in the system. You could try and flush the whole thing shadetree style! Messy though!

 

[British Slave]

I have an 88' blazer with a new tstat, hoses, and cap. i bypassed the heater core because of a leak in the cab and water is moving in the rad while she is running. I STILL get overheating during first warm-up, she will go all the way up to 250 deg, then she will drop to normal and stay there. I know the temp is right cause i have a computer hooked up while reading the guage. The wtaer level is full cold and hot with coolant in the recovery tank. Sombody PLEASE help me!

That's probably normal. The thermostat moves slowly, so you don't get flow at exactly 195. If it drops back to normal, and runs normal driving down the road I wouldn't worry about it.