just out of curiosity, is the engine temperature that is displayed on the dash being read from the area where the thermostat is? if not, where?

the reason i ask is because i posted a little earlier today that my temperature was reaching right at the bottom of the red zone and kinda fluctuate down a bit. i'm worried that i did damage by driving it a little with the temp that high. i'm thinking my thermostat is stuck in the close position because the top radiator hose is RED hot while the bottom is only warm. didnt see any smoke though, so i guess thats good. i've only had my car for a few weeks and i would hate to hurt it.

84 z28 305 5.0 HO a4 82000

 

The sending unit is on the drivers side cylinder head.

The symptoms you described are definatly an obstruction in you coolant flow...thermostat is a good place to start. If your going to drain the fluid anyway, why not replace the water pump and hoses too. Make sure you check the raditor for scale deposits the could be clogging the raditor tubes.

 

Sounds like someone has a clogged raduiator.

 

just put in the 180* thermostat and it works now, the one i took out was 195* thermostat. anywho, my engine runs sooo much cooler now. before it would always run in the 220 range until last night when it got up to the red. now it runs way down at the the first notch up from the bottom. i feel much better.

 

But how are the hoses now?

 

how can a rubber radiator hose be red hot?

 

If the bottom of the radiaor is way cooler than the top, it is indicative of a blocked radiator. The best thing would be to borrow a infra red thermometer and scan many areas of the radiator.

 

the hoses are all ok now. it was the thermostat, it failed in the closed position causing the coolant to sit and boil in the uppper hose. when i said red hot, thats just what i meant, it was too hot to touch, whereas now i can leave my hand on it.

 

well the botom hose will always be colder no matter what thats the coolant intake to the engine .................................................. ...so that is the water that was cooled down by the fan &and radiator little info for those who didnt know!also heat raises personally i would say just have the system flushed for now it cheaper then guesing and pulling straws but also the thermasat is only $2 and a little time if your a handy person

 

Yes, it gets colder as it goes along but what I am looking for are cold spots in the radiator that should not be there. As you are going down if the top is 100 and the bottom is 50, you should see the temp going down slowly as you scan down the radiator. However if you have a spot that is 100 90 40 70 60 50 lets say, then you have a problem