2G Cooling Question

[nitroazz]

Okay Short dirty and quick

98 talon tsi awd.

PR race rad install with shroud and fans.

Both fans work fine.
Temp Gauge almost at full.
Overflow just starting to leak.

I assume I missed an air bubble, am I correct in that?

 

[tenn-gsx]

Did you turn on your heater when you serviced the coolant? Let the engine cool and check your coolant level. Top off as needed. Start rev to 2k or so and turn on the heater. Keep cap off for now and see if the coolant level drops. If it does top off put cap on and maintain 1500-2000 rpm till temps stabalize. If you dont get heat out of heater you may need to rev higher and fluctuate throttle. If temps rise to where it is going to overheat shut car off let cool and repeat.

 

[peteb69]

I agree with tenn-gsx. You need to make certain the heater core is full before you top off for good. Be certain to let the car cool down prior to your final top-off.

 

[luv2rallye]

tenn-gsx has a good technique although turning on the heater does nothing in DSM's since coolant is always flowing through the heater core. We have a blend door actuator assembly that controls hot air flow.

Can also try "Burping" your cooling system. With the engine cold open up your radiator cap and squeeze the lower radiator hose, if air bubbles come out, thats your problem.

Also after completely warmed up, fill overflow to upper mark and let cool overnight with cap on. If no leaks it should pull coolant out of the overflow as needed to top off radiator.

 

[tenn-gsx]

Turning on the heater will give you a good idea if your whole system is circulating though. If you dont get heat then you know you have air trapped in the core and your cooling system is not full yet.

Also after completely warmed up, fill overflow to upper mark and let cool overnight with cap on. If no leaks it should pull coolant out of the overflow as needed to top off radiator.

I wish i could do this. I have an aftermarket overflow tank and have no way to fill it.

 

[nitroazz]

Also after completely warmed up, fill overflow to upper mark and let cool overnight with cap on. If no leaks it should pull coolant out of the overflow as needed to top off radiator.

I wish i could do this. I have an aftermarket overflow tank and have no way to fill it.

Same here. Thanks for the quick help. I was pretty sure that's all it was with this one. I'll get it done after work tonight.

 

[nitroazz]

Okay, bled the system. Air bubbles were very few and far inbetween. Heated it up to operating temp, everything seemed good to go.

Test drive, had to cruise at 20mph to get out of my living area. Temp was fine.
Hit open road after about 5 minutes. Boosted at about 12# upto 65-70mph for about 5 minutes and then turned around and came back at same speed.

Once I hit the houses and 20mph, my water temp started to jump back up like before. When I parked it was about 3/4 of the way to the top. and my overflow is dripping coolant again.

Heat worked fine and blew hot air.
I am going to try to bled again but is it possible my Tstat is gone?
Thanks

 

[tenn-gsx]

So you have good temps at hwy speed but not in town speeds? Are your fans seeing the voltage required to spin full speed? Tstat is possible yes. But there is something else here imo. The coolant bottle overflows after the drive. This could mean HG.

 

[nitroazz]

Voltage for the fans should be good. It seems that the passenger one takes forever before it kicks in. I control the a/c one with the a/c button ( a/c removed). I used the wiring faq from the site to accomplish that portion.

I guess it may be time to do a leakdown test then...

 

[ericemery]

A thermostat is super cheap. If your leak down test works out, I would stick a new stat in.

 

[josh1095]

you have the correct radiator cap? if not, and the spring is too weak it will dump fluid to the overflow early and keep ## system at a lower psi. higher the pressure, higher the boiling point. and vice versa.

 

[nitroazz]

I have the same rad cap that came with the car. I guess when I go back to work I can test my cap to see if it's weak springs. (z)

 

[nitroazz]

Replaced my Tstat with the only one I had available in the whole city of Edmonton.

One place sold me the 420a. Lame morons.

So between changing the rad cap and tstat, I have since fixed my overheating problem. Thanks for the help. It was the Tstat. seized shut.

 

[Doubleot]

My buddy had the same issue on his Evo.

Glad you got it figured out.