Hey guys, just took the car out for a little drive tonight and i looked down and the hot cold gauge was all the way on the red line. I do have fluid in the radiator, just checked that. Im kinda confused because its about 35 degrees here at night right now and the car is still as far to the H as it can go with the cooling fan on. Does anyone know why this would be!? Also, the heat isnt working now. The heat is on full blast and only cold air comes out.
Cobra running hot!!! What is going on?!
- Thread starter 1997stang
- Start date
Engine overheating and no heat.. Sounds like the thermostat is stuck closed to me
I do have a diablosport predator tunner, could i have accidentally turned that off or set the temp too high?
I'm w/ Un4Given on this...when mine was doing it I also had some air bubbles in the coolant system 
I'm w/ Un4Given on this...when mine was doing it I also had some air bubbles in the coolant system
Thermostat is an easy fix, but how hard is it to fix air bubbles in the cooling system?
Water pump.
This is also possible, but unlikely without hearing grinding/whining in the pump while running. If the pump locked up, his belt would probably be toast as well. OP, remove your fan belt and turn the water pump pulley. Listen for any strange noises.
Top of the page, there's a how to section. Follow the directions for burping the cooling system if you have to drain the coolant
Last edited:
Does the water pump not pump directly to the heater core and then back to the engine?
They are made to circulate to the heater before the thermostat opens.
They are made to circulate to the heater before the thermostat opens.
Now that I am not 100% sure on. If that is the case, which makes a lot of sense, I do believe your diagnosis of the WP is correct.
nope thermostat is mechanical and opens by itself when the coolant gets to a certain temp. +1 with it being the thermostat or water pump.
Did you check the level of the coolant at the crossover or just at the overflow? Check it at the crossover as you could be airbound if you had any work recently done to the cooling system.
Could the fans be turned off in the tuner by mistake? You do the tune yourself or change it recently?
Could the fans be turned off in the tuner by mistake? You do the tune yourself or change it recently?
could be a dead heater core as well, I would start by changing the T-Stat, Be sure to follow the refill instructions.
So one day, I get in my car and it's running way too hot and the heater air was cold. I thought of all those things everyone already posted and it ended up being air bubbles in the system. I burped the system and I haven't had any problems since. Do the easy thing first, burp your cooling system, before taking parts off your motor.
Yep, that happened to me.
How do you burp the cooling system?
I stole this from someone else:
When purging the air from your cooling system, the car must be running! and the heater must be on, this is best done after the car has been sitting overnight the car must be level as well.
1) Remove the crossover tube filler cap, rad. cap on resevior tank also off
2) Turn on the vehicle, turn on the heater to full HOT
3) Wait until the thermostat opens up, usually at the same time the fans come on, you will notice the water start to flow, this is when you add water/antifreeze into the overflow tube, when it is full, put the overflow cap back on on top off the overflow tank as well, though you shouldn't need much, since it fills at the same time as the overflow tube!
If you have air in your system, it's usually in the heatercore or connected lines or engine. Hope this helps.
** Also, when I burped my system, I too did it on level ground, in my driveway. You don't have to raise the front end. It should burp itself after the T-stat opens. Remember to run the heater on full in case the air is in your heater core.
When purging the air from your cooling system, the car must be running! and the heater must be on, this is best done after the car has been sitting overnight the car must be level as well.
1) Remove the crossover tube filler cap, rad. cap on resevior tank also off
2) Turn on the vehicle, turn on the heater to full HOT
3) Wait until the thermostat opens up, usually at the same time the fans come on, you will notice the water start to flow, this is when you add water/antifreeze into the overflow tube, when it is full, put the overflow cap back on on top off the overflow tank as well, though you shouldn't need much, since it fills at the same time as the overflow tube!
If you have air in your system, it's usually in the heatercore or connected lines or engine. Hope this helps.
** Also, when I burped my system, I too did it on level ground, in my driveway. You don't have to raise the front end. It should burp itself after the T-stat opens. Remember to run the heater on full in case the air is in your heater core.
Last edited:
It should have been refilled properly and burped when you installed the new Stat!
Leave the reservior cap on,remove the crossover plug,start the car let it idle and come up to temp,you'll have coolant overflow out from the crossover that's ok let it!
Leave the reservior cap on,remove the crossover plug,start the car let it idle and come up to temp,you'll have coolant overflow out from the crossover that's ok let it!
Users who are viewing this thread
