I'm having a weird overheating problem, I just installed my engine last week. I bled the system about 10 times now. The car runs cool about 180 until I get on it, then it starts heating up. It went in to the red friday, so I shut it off and opened the bleeder and the temp droped back down. Saturday I bled it and drove it, and bled it, over and over. I let it cool in between And I wasn't getting much air out. Today I bled it, topped it off, and went for a drive. I drove for about 15 miles on the high way no problem, then I took it on a side street up a hill and when I got to the top it was in the Red! I pulled over and shut it off, I opened the bleeder and steam came out. I let it sit for a moment, And when I started it I held it to about 2000rpm and you could see the temp come down, but when I let off it went back up. So I said screw it and took off trying to keep the rpms up. Plus I put the heat on. I went a block down the road and it was back to normal 180. And stayed that way. But I did notice the heat was getting cold then hot.
It seems like when its under load its heating up.
Could it be a hose leak?
Could be my antifreeze mix, to much water?
Could it be debris in the rad?
By the way, This is a new water pump and a 160 stat (the right one) and I flushed the rad, but not the block or heater core. Also tuned.
Sorry so long, Thanks

 

unless changed in the programming, the fans won't even come on till 220-235

 

The fans are on, It was programed by madz28.com. And its going in to red.

 

Take the radiator cap off and start the engine. Check to see if the radiator fluid is circulating through the radiator. If it's not the waterpump is not working or you forgot re-install the drive shaft.

Were you able to bleed from both bleed points on the water hoses? Are the fans running after the car heats up? Is the air dam on?

Too much water will cause the mixture to boil at a lower temp and too much antifreeze and it will not cool as efficiently. You really need a 50/50 mixture for best performance. I also find it helpful to put some fluid into the overfill tank that way you don't have to keep topping it off.

 

The waterpump drive shaft is on, I can bleed out both screws, and the fans come on after it heats up. The hose going to the thermostat housing dosen't seem to get very hot. Is that normal? Air dam is on

 

I would say that is not normal given the high temps you are seeing. Try your old thermostat if you still have it.

 

Just took off cap and started it, cars temp is at about 170, the fluid just came up out of the rad unless I gave it gas then it would go down go down. Also, Its only about 65 degrees here today.

 

Is it possible for the gauge sensor in the head is bad? Could you hook a datalogger to it and see what the computer is seeing?

 

I can try that tomorrow. Thanks, anymore ideas?
Update: I checked my overflow and it was very low, so I filled it up about half way. I took the rad cap off and it was full, so I tried to bleed it again and I had no bubbles from the themostat one but nothing came out the top bleeder. So I started it with the heat on and opened the top bleed until coolant came out. Then I took it for a ride it ran cool until I Launched it once then it started heating up. Just as I got home it went into the red. I shut it off and checked the over flow and it was filled to the top! I opened the top bleeder for a second and a little air came out. then I started it again and the temp went right down to 180. Could this just be a bad radiator cap?

 

have your radiator taken apart and clean out the individual rows

 

Well I think I got it fixed. I tested the rad cap and it was bad, so put new one on but it still over heated. Then I changed the thermostat, no good. Then I changed the NEW waterpump with an old one I had, BINGO. I guess the rebuilt pump from Ebay was no good. Thanks everyone.