NO HEAT !

Well...it's that time of year again...time to defrost the windshield in the mornings. Thing is...is that I have no heat.

My temp gauge is in the normal place when it warms up. I had a new waterpump installed about a year ago, so everything should be okay on that end. When I turn the knob from blue to red (cold to hot) to get some warm air...I'm not feeling any resistance. So, I'm guessing maybe a cable is loose/off, or something is going wrong there. I've taken the glove box down to see if I could find anything wrong there, but did not.

It's a 1998 Blazer.

Any suggestions?

Thanks =)

Brrrrr

OKay...major bummer. I drove the truck until it was warm, parked it, shut it off, checked the hoses going in thru the firewall. Facing the windshield, the hose on the left was warm. The hose on the right was not. Heater core problem, right?

What's next?

Still freezing.

Bl> Well...it's that time of year again...time to defrost the windshield in

I had heard that the stuff crystalizes. Do we have to run the Dextron or is there a choice?

I think that's what I'll have to do...have someone flush it.

Thx

Sam wrote:

Dextron is transmission fluid, DexCOOL is antifreeze. If it is not serviced and maintained like it should be it can get kinda sludgy. You can run the green stuff but you need to get ALL of the Dex out of your system before refilling with the green as the two don't play very nicely together.

I would recommend sticking with the Dexcool. When properly maintained it's a decent product. This means keeping the overflow reservoir full, making sure the rad cap is working correctly, and flushing the system/replacing the coolant every 3 years or 50,000 miles. GM says 5 years or 100K mikes, but I've found 3 years or 50K to be a bit more realistic.

Doc

I agree with Doc. Also, my 2000 S-10 (with the same control head I presume) has NO resistance to the temp. control knob. I found on my

94 that resistance on the slider to control temp. that the resistance was related to the fan speed. On this truck, NO resistance at all...

Ooops! Wrong word.

I bought the truck almost 2 years ago. The first thing I replaced was a waterpump. Since then, I aways keep it serviced, but haven't flushed the system as of yet. From what I understand, I should back-flush it and I could do this myself by using a garden hose. Anyone care to instruct me or point me to where I can find that info? Also, I've heard about "burping" your system. What exactly is that?

Thanks!

"Doc" wrote:

Okay, here goes:

1. Drain radiator. Petcock and drain hose are on the passenger side of the rad, fairly easy to get to.
2. Those heater hoses you were feeling where one was hot and one was cold...................the HOT one is IN, the COLD one is OUT.
3. Remove both of the heater hoses from the heater core and shove the business end of a garden hose (those cheap brass pointy nozzles work great) into the line that was COLD (the out line). This is reversing the fluid flow and will backflush the heater core.
4. Avoid sludge as it flies out.
5. After backflush is complete, put the hoses back, refill with Dex and be on your way.

A complete system flush and drain is a PITA on your vehicle as the block drains are next to impossible to get at, but this will get your heater going.

Doc

Thanks Doc. I have a couple of questions...

Why do I have to drain the radiator?

How much pressure should I allow into the OUT side of the heater core?

If I'm flushing it with water, how do I get the water out of the heater core when I'm finished, or does that matter?

Do you know how to "burp" it? Or do I need to worry about this?

"Doc" wrote:

Inline....................

To get the old fluid out as it is most certainly in need of a change! Not necessary for a backflush of the heater core, but recommended by yours truly.

As much as your garden hose will put out!

You could blow it out with compressed air if you have an air compressor and a blow gun, or suck it out with a shop vac, but it really isn't necessary as it'll just mix with the coolant when you refill and won't dilute the mixture too much.

Yeah, this is really easy to do. Burping the system just allows the air trapped in the system to escape. The easiest way to buy a venting rad cap (I prefer the ones made by Stant) for $5 at your nearest parts store. After servicing the system, start the vehicle and allow it to reach operating temp (t-stat OPEN). After the stat opens, pull the lever on the rad cap to "burp" the system to the coolant overflow tank.

Repeat until no more bubbles appear in the coolant tank when you vent it.

Doc

I'm going to take it in soon and have the whole system flushed.

But anyway...the garden hose wouldn't reach from the back of the house, so I backflushed it by reversing the input hose and finagling it to the output side of the heater core and put a cut off piece of rubber tubing on the input side of the heater core dumping into a plastic bag (to avoid a mess). Fluid came out fine,not much gunk...but it's working fine now.

THANKS!

"Doc" wrote:

Anyone have any comments about the new yellow coolant that can be used with the green or the orange?

Dave