Clogged heater core?
 

Is this a common problem? I think that is the problem.Everything in my wifes Blazer seems fine coolant is full and flows and the heater hose on one side gets hot but the other side stays cool.I checked at the firewall and think the core may be clogged.I just fixed this problem on my Dodge Dakota which is probably why I checked.Any help or Ideas would be appreciated.

BTW I don't work on this thing much,and I'm building a 68 so I spend most of my time over there.

BTW It's a 2000 if there's a difference.

Re: Clogged heater core?
 

Sounds like the culprit to me. I don't know how you do it. But I take the bottom line off, and then hook a water hose to the other and see how well it flows.

Re: Clogged heater core?
 

These are a real pain in the ole butt. I agree with the above. you probably will have to flush it alot. I've done a couple of these and it takes a while to get all the crap out but most of it will after continued flushing. It beats replacing the core though. It is not an easy job. Unless it leaks I would not attempt to replace it unless you have alot of time. You will have to take the entire dash out.

Re: Clogged heater core?
 

If it ain't broke don't fix it.I planned to just flush it.I already have a flushing adapter since I have to do my Dakota about once a year.I guess they use a smaller tube for heater cores than they used to.I have seen it on older vehicles but it seems like new ones clog more often.I was mostly curious as to whether this was common on the S-series like it is on the Dakota.I think I will flush the radiator also since it has never been done.the truck only has about 55,000 on it.

Re: Clogged heater core?
 

the main reason these are a problem is 3 fold. first GM put this sealer stuff in the system. it acts just like your blood when it clots up on a cut. second is the fact that the core is mounted so high in relation to the rest of the cooling system. this leads us to reason #3. Dexcool gels up when it contacts air. every time you open the cap or anything else you get air in the system. just a small amount but it adds up. the air rises to the top (heater core) where it not only gels up it also makes the sealant do it's thing.
follow the hose that comes from the top of intake on pass. side. this is the feed to core. you need to remove both hoses and flush backwards with lots and lots of water.

Re: Clogged heater core?
 

Backflushed and flushed several times and replaced the spring clamps with real ones.It will run you out now.Thanks for the ideas.

Re: Clogged heater core?
 

Its a very common problem with the S10s...

Re: Clogged heater core?
 

Useful information...I would have never guessed this at first.

Re: Clogged heater core?
 

make sure you are careful when flushing the heater core. I must have used too much pressure or did something else wrong and it broke the heater core. They are REAL pain to change. Here is what you get to do to your dash to change it out.

Re: Clogged heater core?
 

That does NOT look like fun!