had a 180 hypertech and it started getting up to 240 degrees so i thought the stat went bad. changed it to a 160 hypertech and took it out yesterday for about an hour and beat the daylights out of it and it never went over 185.
take it out today driving normal and it's going back to 240 :banghead:.
i've heard some of these aftermaket stat's are a POS but is it possible to go bad in a day? The fan is programed to come on at 195 and they seem to be working fine. Could air pockets do this or could the water pump go bad and cause this? any ideas? HELP....HELP.... :banghead: :banghead: :banghead: :banghead:

thanks
mike

 

air pockets can and will do that, you need to properly bleed the air out of the system. On some cars its a bitch, i dunno bout a vette

Dave

 

First of all a thermostat controls only how cold the motor will get NOT HOW HOT is will get... the only difference between a 160 and a 180 is the point at which they open/close... a 160 stat will keep your car from going below 160...a 180 will keep your coolant from going below 180.. they have nothing to do with making your engine run colder... the cirulation of colder air through the radiator transfers the hot temperature of the coolant by conduction.. if the radiator is not seeing cool temps then there will be no heat transfer. you need clean radiator fins... you need cirulation of air... ( using the fans to draw air over the fins at lower than programed speeds... you need a reprogramed fan program or a fan contoller.
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).

For early model years:
Low speed fans come on at 219,high speed fans come on at 228,low speed with a/c on...

 

the strange part is why 185 one day and 240 the next?
i've checked there's no obstructions.

 

If there are no visible external obstructions, then it could be an internal blockage (thermostat not opening), a bad water pump that is intermitently not pumping, or a bad themperature sensor. I would guess that last one. Happy hunting. :D

Jim

 

was the outside temp warm the first day and cold the second day?

 

nope both days about 65 degrees...
can these water pumps go bad? or are they able to work every now and then?

 

i have no experience with bad pumps. did you verify that both fans are on at that 240 deg. water temp.?

 

There is a special procedure for getting the air out of the system after you change your thermostat. The instructions should have come with it. I think the reason for this is because the vette has reverse coolant flow, unlike a normal car your vette coolant goes from the radiator to the top of the engine and then flows down. Even so, I believe that with time the air would work it's way out and I would have to wonder if that thermostat is working correctly. I had a problem with my hoses colapsing due to a vacuum in the system when the engine cools down. Check your hoses when the car is cold to ensure the hoses are not colapsed, if they are open the cap and let some air in.
:seeya

 

No reverse flow on a LS1.
Water pumps will only stop pumping if the bearings seize, you'd know about it then.
The Corvette does use a funky setup with a pressurized surge tank (they have since at least the c2), I'd follow the service manual for bleeding.

 

Are you sure your readings are accurate? Sure the temp sensor is not faulty?

Good luck. :yesnod: