no heater lately

[Mike Mercury]

hey peeps (and you pervs too... )

It's been getting worse as the days go by but I have little to no heat coming out of my 2003 S-10 CC. Air flow out of the ducts is strong, just the air temp is luke-warm at best.

The engine temp is up around 190-200; radiator is hot and pressurized. But after a drive I can lift the hood and feel the heater core hoses and they are cool to the touch (one barely warm the other cool).

question: the temp selector control on the dash... does it just control an airduct flapper door, or does it actually squeeze off coolant flow going to the heater core... via a remote valve?

I ask because some vehicles do try and stop coolant from entering into the heater core; while others let coolant flow continous through the heater core - relying on internal airway baffling to control cabin temperature.

And any other troubleshooting suggestions would be welcomed.

[HenryJ]

There is no heater control valve for the coolant. Still running dex?

[Mike Mercury]

yes, still -sadly- running dexcool.

I bought a flush kit and forced water through the heater core. It was almost completely plugged up.

I didn't have much time, got it going to about 80% heat output compared to what it normally did. Good enough until I can spend more time with it.

What are my options... other than DexCool ?

[HenryJ]

Flush it and go green. Then make sure you purge as much air as possible and upgrade the stock radiator cap.

[LUVMY02CREW]

It's been getting worse as the days go by but I have little to no heat coming out of my 2003 S-10 CC. Air flow out of the ducts is strong, just the air temp is luke-warm at best.

The engine temp is up around 190-200; radiator is hot and pressurized. But after a drive I can lift the hood and feel the heater core hoses and they are cool to the touch (one barely warm the other cool).

Same here... when it was actually cool (mid 30's) here the kiddos were still chilly in the truck when I dropped them off at school, even after engine temp reached normal operating temp. After a 28 mile commute to work, I still wasn't too awful warm. Since then temps in the upper 40's so cabin temp aok for me with what lukewarm air was blowing out.

Took the CC yesterday to my local guy's garage and he flushed the heater core. He just used a couple of "?hose squeezers?" to keep from spilling out too much fluid, then disconnected the hoses from the pipes coming out of the firewall, covered the distributor to keep from it getting soaked, then he just shot water in each pipe for a few seconds until it ran clear. On the floor was a few pieces of muddy looking dexcool looking goop. Does this sound satisfactory or do I need to get some sort of flush kit to make sure. After seeing all he did my "you dipstick" light came on in my head and I realized with a little searching here and asking some questions I coulda done that myself. Oh well, only charged me 10 bucks so not too bad...

Daniel

[LUVMY02CREW]

Oh yeah...and the air coming out really was definately hotter than before the core flush. Temp was about 50 this morning so still waiting for good cold frosty morning to make sure all is well.

Yes, I do have green in now
Had cracked plastic radiator side replaced a couple of months ago, along with getting the radiator ?rodded? and cleaned. Dude flushed engine block also, but I don't recall seeing on receipt any mention of heater core flush

[LUVMY02CREW]

Alright...been a month now and temps dropped down again. The heater worked a little for a couple of weeks, but is now nonop.

From the searching I've done here and elsewhere in cyberspace I'm gonna attempt the heater core flush at home.
I've got it in my head now that I will probably need to do this as a regular preventative thing because of all the wonderful dexcrap that is still lurking around waiting to be loosened up as the days go by
So, I'm gonna try to make some hose contraptions in a few hours that will hopefully ease things in the future. Wifey will hopefully help me to post pictures if my ideas actually come to life like I want.

So now to a couple of ideas...

1. I read on other sites that flushing the heater core, then soaking vinegar in it for a while, then reflushing thoroughly was helpful...
2. I read the same about a plumbing product called CLR...
Does anyone here have experience with these???
ALSO...

3. Can some type of "quick connector" or a "T" be added to the 2 heater core hoses to make things easier in future? Or, would heat, pressure and too much possibility of leaks discourage that? (not wanting to bypass heater core, just have the ability to disconnect from hoses so can flush)

[BADs Crew]

I have never seen an auto parts store that didn't carry a Prestone Flush and Fill Kit. Its inexpensive and works very well.

[F9K9]

I have never seen an auto parts store that didn't carry a Prestone Flush and Fill Kit. Its inexpensive and works very well.

I think he is asking about a method to remove the hoses without losing coolant. Hose clamps that are like smooth jawed vise grips would solve that but, how much coolant is in those lines anyway?

[BADs Crew]

I have never seen an auto parts store that didn't carry a Prestone Flush and Fill Kit. Its inexpensive and works very well.

I think he is asking about a method to remove the hoses without losing coolant. Hose clamps that are like smooth jawed vise grips would solve that but, how much coolant is in those lines anyway?

Maybe I'm missing something but if the hole system isn't flushed you will take the risk of the core clogging again. The flush kit does come with the "T" he is llooking for and it does stay in the system for future use. If he would like to save the fluid he could drain down first to recover most of the fluid and re-use it if it doesn't have clumps of dex in it.

[LUVMY02CREW]

Me thinks I got ya'll confused about what my questions were.
First, please let me respond to some quotes so far.......

...along with getting the radiator ?rodded? and cleaned. Dude flushed engine block also, but I don't recall seeing on receipt any mention of heater core flush

Based on this I was figuring that the heater core had nothing done to it, so I figured the gunk was still stuck in there with the coolant pressure on it.

...if the hole system isn't flushed you will take the risk of the core clogging again.

That is true but hopefully with the radiator repair and flush(green added back) a couple of months ago, not much will be floating around any time soon

I have never seen an auto parts store that didn't carry a Prestone Flush and Fill Kit . Its inexpensive and works very well.

That's a great idea and I will probably use it when I do a whole system flush in the future. Yesterday, I was mainly concerned with the heater core only.



Second, please let me try to explain what I wound up doing yesterday and my possibly flawed logic behind it...

From what I have read here and elsewhere, it sounds like the heater core has an annoying tendency to clog up first(??maybe from having smaller channels running through it??). This is why I was trying to figure some way of installing some quick connects so I could back flush it out separately from the rest of the system. I guess in my mind I am thinking that you could say that the heater core almost seems to act like an "in-line, washable/reusable filter"

I looked at fittings, hoses, flush kits, etc at 3 different stores yesterday and I finally decided that less is best in some cases. 5' lengths of 5/8" and 3/4" clear plastic hoses were what finally came home with with me.

I covered the distributor cap and removed the 2 heater core hoses. Just pushed on the clear plastic hoses to the core's firewall inlets. This next part is where it gets a little hazardous and the reason on having clear hoses. I then back flushed the heater core by using my lungs to blow out lots of dexgunk and orange fluid. Followed up that with water, then lung power again. Then I shot water back and forth several times through each clear hose with the garden hose. Blew it out again, then added vinegar and let set for bout 30 minutes. Back flushed, blew out, etc several times after that(still more stuff came out). Water finally ran clear and then I refilled core with fresh 50/50 mix, and put vehicle hoses back in place.

I then took my 13 yr old son for a test spin and we rode with the windows down in 39 degree weather just because it was dadgum toasty in the cab

[F9K9]

Sometimes when a fresh mind that addresses a problem is best. Sounds like it worked so far. I was really curious about the CLR thought but, few members seem to be on this time of year. I hope it works out for you. Replacing it is a bear! I have GM's instructions converted to word, in case. you need them. I get PMs or emails weekly from various S10 forums asking for them.

Reed

[BADs Crew]

Glad to hear you solved the problem. If you want to zone the core out in the future you could buy two of the flush kits just to get the extra "T". Add a T to both lines then just use Hose Pinch Off Pliers on the engine side of the T's to zone it out. . Then you could just remove the caps and use a garden hose to flush out the core.

[LUVMY02CREW]

Hopefully it'll be a good long time before I have to get those instructions from you. Gonna be keeping my fingers crossed. Please keep them handy just in case....

And....BINGO....Those pliers are exactly what I was thinking about. The only thing I could think of calling them were "squeezer thingys". Seems like the word "thingy" pops up in my mind way too often when describing stuff.

And the idea of "zoning" off the heater core with 2 t's may be just what I was needing. I'll have to keep that in mind when backflushing next time.

thanks bunches for the replies

[Rebel-Chevy]

so dismorning on my way to school my heat was working perfect so once it got hot enough i thuned it off. when i go to school i turned the heat back on and it was cool air coming out of the vents, i turned it off and on again and messed with all the knobs but still cool air. i got out of school started it back up and the heat was working fine again. anyone have an idea what happened?

[LUVMY02CREW]

Okay, been a little over 2 weeks and had to back flush the heater core again due to lack of heat. More gunk came out. Heater very toasty again this afternoon After I back flush, everything seems fine for a while. All controls seem to be aok, unlike what rebel-chevy mentioned above in the last post.

Didn't do as badscrew suggested with the 2 t's and the hose pinch off pliers, but I'm hopefully gonna get the parts for that before next time.

I had a new thought about this situation while working on it....I'm wondering just how plugged up is this darn thing?????????? So my 13 yr old son and I decided to measure how much new coolant we will add back. It seemed to take about 3/4 of a 20 ounce drink bottle(15 oz) to fill it up till I could see the coolant in the clear hoses.

So now I'm trying to figure out what the capacity of the heater core actually is so I can determine how much more coolant I could add if it is all clear. This hopefully would help determine how much more useful life I have in it, since so far no coolant leaks or smells in cab.

I have searched here and got this about the whole system...GM Fluid and Lubricant Recommendations and found this measurement on the web somewhere (Heater Core, Dimensions Of 8-1/4" x 7-1/8" x 1-3/8"). I simply could not find the actual capacity for just the heater core anywhere.

Do any of you guys have an idea bout what the capacity is or how to find out?????

[Torskdoc]

Rebel Chevy......With changes in temp (winter) the vacuum hoses get stiff and brittle. Hoses in southern climates will tolerate more cracking/splitting/etc. than a cold hose which will shrink which will aloow more problems. Sounds like you have a problem(listed in order of likelyhood) with either your vacuum lines (not enough to accuate motors), the mode doors (in the heater unit itself) or even the accuator motors).

Check your vacuum hoses from the manifold to the vacuum bottle/ball in the fender next to the Master Cylinder. Check the vacuum hose attachment to the 4x4 switch on the Transfer case.

Larry

[Rebel-Chevy]

was just my anti-freeze was low i have a small leak somewhere

[BADs Crew]

Most auto part stores around here have a Cooling System Pressure Tester that you can borrow to check the system for leaks. Once you pressurize the system you can safely give it a close look. If in fact you do have a leak this test will confirm it. If you blew more stuff out of the core than I am guessing you didn't get everything out of the engine block. If it ran clear and you still didn't have heat you could have air in the system. The core could trap air because it is high in the system.

[04crewvt]

Anybody ever pick up the UV test kit GM sells or an equivalent? I saw one at the Dealership I used to frequent there were 4 or 5 bottles of UV dye to add to the different fluids and a light to see the leaks. Not sure if it was sold to the public just thought it would be great to have at times.

[Mike Mercury]

WOW; I didn't realize this thread still had legs.

As an update; I did the flush thingy to the heater core. There was heat-output improvement... but it wasn't like original. I guess I was now at 60% of what it used to be.

Then this second time I got a quart of the radiator flush chemical, but used it full strength - in an unusual way.

I placed the store-bought flush fluid container in a bucket of hot water... to pre-heat it.

Then I connected my garden hose to my homes hot water line, and ran hot water through the heater core until it got good & hot (sorta pre-heating the core}. Then I forced all the water from the core.

I then took the flush fluid and poured it into the core (both the core and flush chemical were pre-heated) and let it sit for two hours.

Lastly I water flushed the core until I thought all the radiator flush chemical was gone.

That really made a difference because I'm back to within 95% of the heat output as original.

I'ts been quite awhile since I did that; and I've had no problems.

[BADs Crew]

Unusual but very creative. Glad to hear you got it repaired.