cold CUCV

[rizzo]

I have never had a problem with heat, but now that I have replaced my rotting radiator with a new one, I can get very little heat out of the cab heater. anyone else have this problem?

I wonder if my thermostat is bad??

 

[mangus580]

I have been battling this problem in my 1009 since the day i got it!

Would you believe I have run the grill cover all summer with no issue?


It is possible that you have the wrong thermostat in it. I know mine had a standard looking tstat in it when I got it, and thats the wrong kind.

 

[ssgtwright-usmc]

Did you hook up the heater inlet/oulet hoses correctly to the engine block and at the radiator or did you cross them over by accident?????

 

[ssgtwright-usmc]

The bottom hose of the heater core goes to the engine block while the upper heater core hose goes to the radiator.

 

[rizzo]

what is the correct thermostat? I have never heard that before?


I will check the hoses. I never touched them.

 

[mangus580]

Incorrect tstat = $5

Correct tstat = $30+


Autozone lists one for the 6.2, but when you get it, it looks just like one for a SBC... and its not the right one. The proper one for the 6.2 is much more expensive, and looks totally different than the one for a SBC....

Its the best I can describe, I dont have any pictures. Maybe some one else can help with that.

 

[mangus580]

Try this...

 

[superburban]

I just had this conversation with my friend who bought a 6.2 blazer. I told him that he needed a hockey puck, not a regular looking t-stat.

 

[ssgtwright-usmc]

Im surprised that you didnt replace the thermostat and flush the system at the same time if you had your radiator replaced.
Check hoses first to see if they are connected right and if they are then I would still change out the thermostat and flush the system out.

 

[AJMBLAZER]

Random question but can these get an air bubble near the t-stats?

Ford Rangers with the 4.0L V6 have a design flaw in that they can get an air bubble there if the system isn't purged of air properly. After a while the air builds up there, the t-stat never opens, and the vehicle runs cool while the heater never works.
Just wondering if this is possible with these 6.2L's?

 

[JAsher45]

yes they can get an air bubble in the system..with a cool engine, let the engine run with the cap off and heater on ..watch the flow in the radiator you will see the fluid level drop after the T-stat opens then fil with more coolant.. sometimes it will take up to 30 mins to bleed the air out of the system.

 

[Jetnoise400]

Any chance your heater core is plugged up from rotting radiator syndrome?

 

[CCATLETT1984]

FYI try to heat the aluminum crossover before removing the bolts, they will be seized and might crack the housing. Rizzo, if that happens to you I have a spare i can pull for you.

 

[rizzo]

the heater core works fine, I only had this problem after the radiator swap. the old radiator was half rotten and probably did not cool to capacity.

I checked the heater hoses today and they are right. My dad noticed that the heater hose setup will always bypass the thermostat, never letting the engine warm properly. I was thinking about re routing the heater core return to the pump like normal (maybe Y it to both). In the meantime I will experiment with a piece of cardboard on the grill.

 

[rizzo]

FYI try to heat the aluminum crossover before removing the bolts, they will be seized and might crack the housing. Rizzo, if that happens to you I have a spare i can pull for you.

thanks

 

[CCATLETT1984]

ya know, It might be easier just to swap that whole crossover than mess with the tstat.

 

[rizzo]

yes they can get an air bubble in the system..with a cool engine, let the engine run with the cap off and heater on ..watch the flow in the radiator you will see the fluid level drop after the T-stat opens then fil with more coolant.. sometimes it will take up to 30 mins to bleed the air out of the system.

I have run the truck several hours since the swap, but with the cap on tight. could there still be a bubble.

 

[ssgtwright-usmc]

Yes, try with the cap off, when the thermostat open, it will have a drop of fluid level in the radiator.
At this time add more fluid/water.
Turn off engine, let cool and run engine again let it warm up and see if you have heat then.
If not, change out the thermostat.

 

[msoumas]

Very little heat? We ought to trade. Mine's got none! I turn on the heat and nothing happens.

 

[JAsher45]

the coolant system is a big pain to bleed.. the crossover and upper radiator hose are so high almost the same level as the radiator. but once you get it all out it should work just fine..

if you want you heater to work better.. there is some plumbing changes you can do like on the HMMWV system. plug the radiator where your heater hose comes out. on your water pump there is a pipe plug on the same side... remove it and install a 45 degree threaded hose fitting. then hook your heater hose there. it is more of a closed loop system