Had a mishimoto Radiator since March of Last year, the only complaint I had was installing and that heat sucked (Bubble in the lines I believe).

However, I have a HUGE problem now... We drained about a gallon or so of coolant out of the radiator 2 nights ago in order to put a coolant temperature adapter in the upper hose. So we did, and I wired up the gauge and all goes dandy. Drove it to work pretty hard the next day, yay, everything's great, I have a working gauge.

And then last night...
I was on my way to alocal grocery store, and I see my stock temp gauge is rising, past the middle mark, yet my coolant temp gauge isn't leaving 190. It got to the tic mark below the H and I pulled over and turned the car off. I then started it up again after inspecting the engine bay and the needle dropped to middle, so I went on thinking a bubble was burst. Well, same thing happened about 3 minutes later. After it returned to middle, I drove the car pretty hard, and then pretty normal, I even held it at 4500 for about 1/2 mile and everything was fine, so I figured I wouldn't ask questions.
This morning, coming to school, same **** happens, except worse. The needle was now ON the H, yet the coolant temp gauge is still posted at 190, I cranked my heat all the way up, and nothing but cold air is blowing out of the vents.

WHAT THE EFF?!?!?!?!?!

I also might add that we used the same coolant and put it in the radiator, the Overflow tank is about half full (about 2.5 times the amount that was in it before.) So if we used the exact same amount of coolant, and there's more in overflow than before, there must be a bubble, right? But why is that bubble not working itself out, and why the hell is the car overheating. (Rad. Cap also leaked a little bit of coolant out and was infact steaming. Not a substantial amount where you could see it with the hood closed and when you open it there's smoke, but there was infact steam coming from that cap.)

 

You need to bleed the air out.

 

That's what I suspected. Now onto a little bit more helpful response.
How?

EDIT: I also might add that I took it home from school and stayed under 2K the ride home, everything seemed fine, so when I got home I torture tested it, held it steady at 5500 for about 1.5 minutes. and it was fine. I even took it to work and came back and it was fine. I noticed that there was also less coolant in the overflow tank now, leading me to believe that the bubble in the line created a vacuum when it cooled down and sucked coolant in through the overflow hose.

 

You can run the car from cold with the radiator cap off to see if there is any air in the radiator, you need to locate the bleeder valve, when facing the engine it is top left of the plenum. Unplug it and start the car and rev it up a couple of times. That should do it.

 

bleed until you get consistent hot air from the vents when the heater is on without the A/C. later, check the level of coolant in the overflow - the level when hot should not vary, and the level when cold should not vary.

 

not sure if this has been mention but bleeding our cooling system is a bit different. We have a bleeder valve on the passenger side firewall near the battery.

edit: mentioned in post #4.

 

like mentioned above use the bleeder valve.

Best method I have found is to make sure the car is HOT and open the bleeder valve slowly. You'll hear the air escape and when it stops hissing close the valve. Do that several times in 5 minute intervals and you'll be done in less than an hour.

 

Sweet deal. Thanks for the responses. I will bleed it today when I get home from school. Anything on what this said bleeder valve looks like and whether its on a line or not.

Thanks alot, again.
I'll also add that my heat has been absolutely terrible since I had the radiator. I presume that bleeding the line will fix this.

 

 

Awesome, thanks, I've bled the lines a total of about 3 times today, it's helped alot, problem is almost cured.

Thanks alot guys.

By any chance, do any of you know where the stock coolant Temp Sensor is?

 

its on the rear coolant pipe towards the passenger side of the car.

 

The little blue connector on the right side of the coolant log in this picture yours should point straight toward the fire wall instead of up like mine, as bigc said you will find it on the pass side rear not far from the bleeder screw.

 

really needed this.... thanks guys...