KR with cooling problems

Wow you got me!sounds like you covered all the bases did you try the rad cap my K.R ran really warm till I changed the cap.Sounds like its not circulating at all could there be a blockage.Try it with no thermostat,alot of guys don't recomend running without one but it would be worth experimenting with. Good Luck

 

Check this: there is supposed to be a spring inside the lower radiator hose so it doesn't suck closed. If you can take your hand and squeeze the hose together, it is not in there.

 

When you say it over heats, does it boil over or is it the guage telling you it's hot? If it's just the guage telling you it's hot and it's not showing signs of anything else, then I would say it's a bad guage or sending unit.

 

I basically have the same car as you. My motor was bored 30 over and I decked the block and shaved the heads just a touch. Runs alittle over 11 to 1 CR, ported heads, bigger cam, headers etc. I have never had a over heating problem with it. Can drive it in 90+ degree. First thing to look at is the gauge. I installed a mechanical temp. gauge to see what it actually is running at. How hot is to the right of straight down? I didn't know either, thats why the gauge is so important. I have a 180 degree stat and the car will run 180 to 190 all day. Since you checked the flow by seeing the water run with the cap open I will assume there is no blockage or air pocket. Is the coolent to water ratio correct? The fan shround sealed againest the rad? Have you checked the timing? To far retard and it will run hot. Check your plugs, if white in colour then you know timing is out. Have you tried Redlines water wetter? First thing you have to do is find out how hot it really is running, simple a/c temp gauge in the rad fluid while it is running will do it if you don't want to install a gauge. Last resort would be a aluminum rad. Had my rad guy make me one useing my original tanks and side supports. Never know it wasn't the original rad. This may be way out there but is the water flowing in the correct direction?

 

A tight motor will run alittle hot but your beyond that now. The reason I asked about the water flow is I rebuilt a 5 litre with the serentine belt system. Stupid me routed the belt wrong which caused the pump to flow reverse. Car would idle fine but soon as it warmed up the thing would just pour out of the rad. I am pretty sure if you are standing in front of the car the water should flow from left to right but I will have to check to make sure. Eldelbrock makes a high flow aluminum water pump that flows 30% more then stock. My rad only cost me 250 bucks CDN to get made. It still is a 4 core rad but it has more rows thus more cooling fins to disapate the heat. Your sure the stat is openning? Try it without it just to see if there is a diff. By eliminating each possible cause (easiest first) eventually it will be solved. Keep the faith, been there done that.

 

It's now July 05 did you solve your overheat problem with the 428CJ?
If not I may be able to help,as I once had the same problem as you and did all the same steps, all to no avail. Until I inspected the block and found the culprit,that was 225,000 fun miles ago and I live near Hell (Phx Az) to be exact.
Let me know if you still need the info on overheating FE motors.

 

I have a couple of questions which may be silly, but since you have gone thru about everything, why not. Are you using a fan shroud? This question may be a bit more bizzare, have you checked your engine timing? In my limited experiances, these two things have made some kind of a difference in the temp on my car.

 

Guys,

I have a rebuilt CJ .30 over that is also running hot. I am fairly confident it is the fan clutch. The car is an AC car but I do have an original non-ac clutch as well. WIll the car run hot with the AC off with the smaller clutch???

Where is the best place to have these original clutches rebuilt?

 

Is your car an auto ?
I bet the gearbox cooloin lines ar not working , then they will run hot . I had that on a GT350 car i had !!
John