I just flushed my coolant last night and drove around the block and the temp went pretty quickly up to 240??? When I pulled the car back into the garage and squeezed the coolant hoses, they where VERY hot??? It was running fine before I flushed the coolant? I don't understand this? :banghead:

A good start would be with the thermostat, the fail safe unit is a excellent replacement about ten bucks, try NAPA or your local speed shop. In case of failure it will stay in the open position and not cause a big headache when youre BLASTIN down the road.

got 2 things that might work 1 check and see if your fan is kicking on. also put a 180 thermistat in try it and let me know mine was doing the same thing and it blew the head gaskett.

Possibly some air in the system?

You have air in the cooling system. Let it cool down. start it up, then full up with coolant while holding RPMs at 2500, should be fine.
David

Don't you have to fill the fluid up while the car is running to the point that the fan turns on and sucks the fluid in so you can fill it the rest of the way?
Brad

i have same problem. just bought vette was running fine. the low coolante light came on and it started runnning above 200. ran at 170 before. changed termastate. finnaly took it out.hose was hard as a rock after i drove it. had local radiator shop check it . said heaster core was leaking. replaced it. still get low coolante light. still running hot. i'm planning to drain system and put water and baking soda in and flushing it. then trying it out. am i wrong?

got 2 things that might work 1 check and see if your fan is kicking on. also put a 180 thermistat in try it and let me know mine was doing the same thing and it blew the head gaskett.
The fan in an '84 doesn't come on until 238°. So it wouldn't have been on for long before he saw the 240°. A 180° thermostat isn't open any wider at 240° than a 195° thermostat. A waste of time and effort if the old stat works.

RACE ON!!!

I just flushed my coolant last night and drove around the block and the temp went pretty quickly up to 240??? :banghead:
Unless your flushing dislodged something that formed a blockage (unlikely) in the cooling system, DRMZO7 and SportsCarsUnlimited seem to have the answer. Follow David's instructions to "burp" your cooling system. I like to warm the engine up until the thermostat just opens before I rev it and add the coolant. If it is convenient, it doesn't hurt to have the front wheels on a ramp. Then, after it cools,I like to remove the cap and top it off. This isn't necessary if the reservoir has enough coolant, but I like to double check. The problem is caused by the fact that the fill point is not the highest point in the cooling system.

RACE ON!!!

Don't you have to fill the fluid up while the car is running to the point that the fan turns on and sucks the fluid in so you can fill it the rest of the way?
Brad
The fans suck fluid? My fan is in the air stream, not the coolant path. I don't know of a stock C4 that starts a fan at a temp lower than the boiling point. If you remove the cap when the fan(s) come on you are likely to get scalded. Read the warning label under your hood on your fan shroud or radiator. If you leave the cap off, the coolant will boil before it reaches the fan on temp. The coolant can't get any hotter than the boiling point which isn't high enough to activate the fan.

Do it David's way.

RACE ON!!!

Get the 180* or 160* thermostat and while you are at it get a chip. Even when the reservoir is full if there is air in the line it might not suck the coolant in from the reservoir. Open the rad cap and dump it in when it is warmed up. Your thermostat is probably old and could use a new one anyway. And then back to:burnout: