So my heater has been blowing cold for a long time now in the 2004 and i tried to burp out any air that could be trapped in the system yesterday by jacking the front end up and running it to operating temp with the heater on to see if i could get it to push any air out.

now the wierd thing is i figured i would be able to see the water flowing or moving somewhat through the radiator when the cap was off, the water was actualy dribling out of the cap hole and there was 0 movment even at operating temp so it makes me think something is clogged up bad perhaps granted i have 0 overheating issues.

So is this normal? shouldnt the water be noticably flowing when the cap is off and you are looking down into the radiator?

if it should be flowing could my water pump be bad? or the thermostat isnt opening right perhaps?

Maybe just a bad clog? the coolant is very old dex cool. i need to change it asap as well.

Thanks for any thoughts folks.

 

Another thing if its the old dex stuff I'd flush your heater core asap too. This can be done with a shop compressor.

Take the hoses that lead to your heater core off from the ends not attached to your heater core, ie so you have hose to work with.

Get an empty milk jug, and put one hose in that to collect the gunk. You will need to hold or secure the hose in the jug. Then put the air hose in the other side and blow air through the system. I used about 30psi If i remember right.

Once empty hold the two hoses above the heat core and fill with water. Then flush the water out the same way you did the fluid and gunk. Repeat until the discharge looks clean

Put everything back together, top off with new fluid and go for a 15 min drive in higher RPM to finish flushing and refill the system.

Had no heat about 4 years ago, took it to a shop and they flushed it and it only lasted about 2/3 of a year. Did it this way and its lasted me until now with very strong heat Saved a butt load of money too

 

i believe it is the original dex cool. i need to flush that crap out asap

 

Could you use vinegar to break lose any gunk that's built up in the heater core?

 

I've lost heat in my blazer twice. Once when i first bought it 10 years ago. I took it to a place and had them flush the system. Again last year, the heat wasn't very hot. I took it to another place. They flushed it, and put some stuff in the heater core to dissolve whatever crap was in there. I think it cost a little over $100.00. If you can afford it, that is probably your best bet. The fist time it happened to me, I would just take the hoses off the heater core and run garden hose water through it. The water would start to run clear. I would put the hoses back on, and a day later it would be clogged again. I guess there was just a bunch of stuff floating around in there that would just collect in the heater core. Like I said, if you can spare the cash, best bet is take it to someone with the equipment to do a proper job.

edit: You can try tenorsaxdude's method, but if it's original dexcool, it's probably well over due for a flush. I think the interval is something like 5 yr/100,000 miles or something like that. I know you're supposed to add distilled water to it too. If you have ever topped it off with tap water, I hear, is where you get a lot of your scale/gunk build up.

 

Taking it in on sat hoping this fixes it because going to and from work here in denver is super cold some days...

 

Brian_D: to answer one of your original questions...yes I think you should be able to see coolant moving with the cap off. I assume you took the cap off and then started the engine and when the temp gauged showed at operating temp, there was still no flow in the radiator...is this correct?

If so, sounds like the water pump is not working, but the engine would overheat pretty quickly and I think you would notice this right-away....

Interested to read what the shop tells you on Sat. Be sure to post what they tell you.

 

Yep that is the case but it never over heats not even in the hottest days of summer, ever since i changed the thermostat a year ago it has held a perfect temp all the time.

I will for sure post here with the results.

 

All flushed out, heater works now. ^_^