Thread: Need some help/weird overheating issue. Did research, need expert advice

Ok lets see if this one works, yes it was a oem thermo till I poked the middle out, hole to big maybe?

Ok so i don't know what happened to the sound, I changed out the thermo for a stock one and I show what was in there before. I am not positive that it is a working thermo, but i figured it would maybe change somehing. Nope, in the video you can see how tight the upper hose gets, the other one did not get as hot, especially on the radiator end it stayed fairly cool. It had pressure and was hotter close to the thermo. as the temp gauge went up to about 3/4 it started overflowing out of the bottle.

Not getting much help here guys, I switched out the radiator to stock, bled the system, drove it around. No problems until it is sitting at idle, then it will start to overflow after a minute. I hopped back in it and drove around some more, no problems, when I stopped and turned it off it did not overflow again, but it was venting some in the overflow, probably would have done it again if I had left it running. I think I am just going to try racing it and see what it does. It does not seem to be a problem as long as the car is moving. Still no cloudiness in the oil, And it always seems to stay within operating temps. Of course I run 2nd gear pretty much to the floor around that track so not sure how it will handle all that. It did fine in the last main, never blew any water out until the race was over as far as i know. I have put way to much work into this thing to not at least try and race it. I guess I am willing to risk a blown head gasket if it comes to that

Do a leak down test... see if you are pressuring the cooling system.

I have read this a few times and see no mention of your fans...I have to assume they are working properly...right?
all the symptoms seem like a fan not coming on.
so if the fans run with constant 12v they are good the ECU or coolant temp sensor could be causing you some grief

Good idea about the leak down, my brother racessprint cars and am pretty sure he has the equipment to do the test, as far as the fans go, they havent seemed to be working since I brought the car home. But when I pulled off the track 1 was running. I had the timing to retarded i believe and when I pulled off the manifold was glowing, it had melted the passenger side fan wires. But the other fan was running at the time. I have only been hooking up the driver side fan since I had it home. But i havnet seen it come on yet. I checked the big 30 amp fuse and it was fine. Is there another? i couldnt find it. I have another set of fan relays I could try putting in there, and I was going to rewire the other. 1 will work without the other right? I will have to figure out how to make them run all the time. The car does have a g20 ecu, and I did notice some people saying something about the temp sensors possibly causing some problems. Where are those located? I used the manifold off a 95 and the car is a 98. is tht something I need to check out?

you gotta get the fans working man thats the first step. one fan should come on at 210 I think and the other comes on when the ac is on. You can wire them both to the ac button or a toggle switch.

I'm gonna take a shot in the dark here and say you have a collapsed hose. As in the inner layer has come loose and is creating a blockage. Follow eggmans advice and get a real gauge and do the pressure check. There isn't much that can go wrong in the cooling system. It is a fairly simple system. One other thing you can try is putting the car on ramps or jack stands and run the engine to see if you get any air out of it. It almost seems like an air pocket in the heater core.

You said you had the block refinished, how about the head? Also when you decked the block did you have the front cover bolted on? I have seen machine shops not deck the front cover with the block and the head gasket will keep leaking.