Ok so my turbo build is basically all done but i have a nagging coolant issue i need help diagnosing. . .

Basically, coolant does not circulate through the system, i.e. the motor will sit idling and overheat while the radiator is ice cold.

I drove this car with the KA in it for the past year with no coolant issues before I turbocharged it. For my turbo setup i decided to swap in the volvo intercooler and radiator together. There are two main differences between the stock rad and the volvo one. 1. the inlet on top of the rad is on the drivers side instead of the passengers, so i made a rad hose to accomodate that. 2. the volvo uses a pressurized overflow tank setup, so there is no cap on the rad, so the overflow nozzle on the radiator is just open. When the motor starts to heat up and any pressure builds up in the rad it just shoots straight out of that nozzle into the overflow tank. So I thought that perhaps I should block it off so that pressure could build and allow the fluid to circulate. No dice. I removed the rad and hoses and made sure that there are no blockages, they all flow freely when a hose is run through them.

So after scratching my head and trying everything else I can think of I went ahead and removed the thermostat altogether. Now there was coolant flow through the rad and no overheating so I figured the thermostat must have gone bad by some big coincidence. Put a new thermostat in and the problem returned, no flow through the rad.

Riddle me that.

maybe you installed the thermostat wrong? lol jk

ok I think it has to do with if you have a high pressure thermo and a high pressure rad cap.

I'm using a 170 degree thermo and right now there is no radiator cap, no overflow.

Anyone else have any ideas?

If the thermostat is still not opening up, I bet its the thermostat. Did you get one from Nissan? Try yet another one.

air bubble around thermostat? how long has it bin turbo?

I've burped the system multiple times until no more air bubbles come out. I've never had any issues with the thermostat or air bubbles before and I've had the system emptied multiple times before. I've had the turbo on the car for about a month now but havent been able to get past this issue to take it for a drive longer than around the block.

At first, I would suggest just running without a thermo. If you lived in a hot climate or you were having issues in the summer, running without a thermometer wouldn't much of a problem. I live a little south of you, so I know all too well of how cold it gets around here. Without a thermo in the car, it will take forever and a day to warm up.

Chances are its with your thermometer. Sometimes they are faulty from the factory. Perhaps you put it in wrong. When you say there's know radiator cap or overflow, did you just plug the hose that runs to the overflow? If that's what happened, then when pressure builds up in the coolant system within the engine, the thermometer can't open due to the pressure in the radiator and hoses... Just a thought.

do you think you could have blown the head gasket and you are leaking compression in to the coolent creating air bubbles that keep the thermostat from opening.

Problem solved. Turns out all my efforts to burp air out of the system were in vain. I didnt know about the bleeder valve on top of the upper rad pipe. I guess there was an air bubble trapped behind the thermostat. Opened up the bleeder valve, topped off the system and voila. Sucks it took me that long to figure out.

it happens we learn from our mistakes and next time it happens we know what to do and not waste so much time going in circles.