'01 Chevy S-10 Blazer 4x4...... Little or NO heat!!......HELP!!!

This problem started about 2 months ago. I noticed a gurgling sound from the heater core. Almost like water running into a bucket. Now, I have an intermittent heat problem. I've used an over the couter flush, to no avail. Sometimes it will run you out of the truck and sometimes it blows nothing but cold air. Most times, it's simply luke warm air. I can feel the hoses, underneath the hood where they run through the firewall, and the one on the left is hot and the one on the right is cool to the touch. If I squeeze the hoses, while it's blowing nothing but cool air, I get nice warm air afterwards. Soon afterwards, it starts to cool back down again. The engine temp is setting at the normal 190 degree mark on the guage. I'm assuming the thermostat is operating properly, otherwise, it would be running cold or hot depending on the position it would be stuck in..........correct? Is there a chance this thing is air locked or something. Any home remedies to correct this problem? Thanks in advance............ ALAN

 

I'm not a mechanic, so take this with a grain of salt...
When my '93 Silverado was not blowing hot air, I changed the thermostat and that fixed it. According to the temperature gauge, the truck was not running hot or cold, it just wasn't blowing hot air.
As to the gurgling noises, that would about have to indicate air in the system wouldn't it? Are you certain that your radiator is completely full? When your engine is cool, take off the radiator cap and start up the truck. The fluid will circulate. Add more fluid until it won't hold any more, and replace the cap.
Now let some real mechanics chime in!

Pecos

 

Thanks Pecos. Yes the radiator is full. I just finished flushing the system, with a radiator flush from the parts store, myself and made certain the system was full of fluid. I might consider changing the thermostat just to rule that out of the equation, since it's likely the original and is 6 yrs old now. If there's a way to bleed air from the system, I'd sure be interested in hearing from someone who knows how to do it. Anyone else have any opinions.

 

It does sound like a blocked heater core if one of the hoses was cool to the touch. Have you had any overheating problems? If the core was clogged, it would prevent the coolant from circulating correctly.

You can tell if you have air in the system if you see bubbling of the coolant when you remove the radiator cap.

Bring the vehicle to one of those oil changing places and have them flush the system. These machines are good about not letting air back in the system.

Hopefully it's not the heater core, because that requires the removal of the entire dashboard in most vehicles!

Try disconnecting the two hoses from the heater core (firewall) and sticking a hose in either end of a hose. This will get any clog out.

If you end up getting good coolant flow and still mixed hot and cold air, it is probably your blend door actuator. And hopefully it's not that either.

 

Thanks for the reply Mark. I can hear something opening and closing, or whatnot, behind the dash when I change the settings on the heater dial. For instance, turning the flow of air to the floor, defrost, defrost to vent.... etc. All appears to work well with the exception of heat. I'm almost ready to say it's within the heater core. I'm going to try to remove the hoses and push water through it with a water hose to see if I can flush it. That is, IF the new thermostat doesn't take care of it. The parts store is telling me the same thing as mentioned earlier in the thread by Pecos. I'd already have taken it to a mechanic, but they want $90 just to flush the system. That's pretty steep for a flush!!! Removal of the dash is what I DON'T want to do. Any other thoughts out there?

 

My wife has the same vehicle and every year I have to backflush the heater core to get it to blow heat.

 

Mattison........ I have a friend that owned a 2000 model. He experienced similar problems with his also. Flushing seemed to fix the problem for him as well. And it required flushing every year.


Anyone.......... I obviously need to start somewhere, so I picked up a new thermostat and intend to replace the existing one in order to eliminate the possibility of a faulty one. Problem is........ I can't seem to locate the old one on the engine!!!!! Where, on the engine, is the thermostat located? I have a hunch, but I don't want to start removing stuff without knowing for sure.

 

Should be something like the link below. Copy and past

http://www.automedia.com/Keep/Your/Eye/on/the/Thermostat/ccr20041201th/1

 

HotinOKC........ That was it !!!! I removed both lines to the heater core and filled the hoses with HOT water then, using compressed air, back flushed the core. Then, using the same proceedure, forward flushed the core. Best part about it is, it didn't cost me a dime to repair!!! All is well now....... Thank you.

 

Glad it worked out for you! It always feels good when you can repair something yourself without having to pay some Joe Blow to fix it.

 

What's really upsetting is........ How many people has this shop ripped off by actually charging someone $90 for a fifteen minute job that doesn't cost THEM anything to repair? Now, to me, that's disturbing....... :-( ...... How do they sleep at night? At any rate, thanks to everyone here for your helping me get this thing fixed. Still toasty warm, AND I'M LOVIN' IT !!!!! ........ THANK YOU !!!

 

Yes, I just had a incedent with a dealer wanting to charger me $27 per MINUTE. That post is in the "chats & Whine" section of the forums. That is what is so great about this site. People can tell you if you are getting robbed and how to do it yourself. Come back here often. I found my self addicted to this site.

 

Just wanted to stop back in and say thanks once again. The heater is still doing GREAT!!!!! I have since purchased a service manual on my truck for any and all future repairs needed. THANKS AGAIN!!!!! ................. ALAN