Sudden Loss of Heat

[Jay-Sliver]

Ok, so, me and a lady friend went to a drive in movie tonight. The air is a bit cool, so we had the heat on on the way there, everything is all good. Turn the truck off when we got there, after a while the truck got a lil cool, so fired the truck back up to warm it up a bit, no heat. Nothing but cold.

You would think that if the heater core was plugging up, that you would notice a slow loss of heat over a period of time. Don't think the heater core beign plugged is my issue, cus I went from Tonnes of heat, to none. Move the HVAC controls from feet to face to defrost and whatnot, everything is fine there, I can hear the doors moving and all.

Any ideas, or am I on my own with this one?

Jay

[Hammer Head]

How's the coolant level?

[Jay-Sliver]

Coolant level is up. Truck runs at a normal temp.

[Big Mack Daddy]

my fist thought was the thermostat until you mentioned the truck was running at normal temp. so maybe the control is going out and not recognizing you have it set to heat. but idk.

[spideyjected]

I wonder, are there any valves in the heater core lines? If so, I'd check those first.

Jay, you're never alone in planet country

[Jongo88]

Feel your heater hoses. They both should be hot. If they are cool or one is cool then it is clogged....

[spideyjected]

The truck was just trying to make you guys snuggle, duh!

[Stevonator]

I've also seen water pumps do this...vehicle temp is fine...but no heat. Do the following in this order.

1. Check coolant level radiator MUST be FULL.
2. grap a fan blade and rock the water pump pulley to see if the water pump has excessive play.
3 Start engine and warm it up until the upper radiator is too hot to hold onto and is firm.
4. check both heater hoses for heat.

Let us know the results. S10's dont have heater hose valves....although mine does :)

[Jay-Sliver]

The water pump on it is just over a year old. Replaced it Last Feb when I was in trade school.
I think I have it figured out to be a plugged heater core, for these reasons;

1. Hot water into heater core, luke warm water returning.

2. For the past couple months there has been some gurgling noises comming from the heater core. Im thinking the gurgling is the noise the coolant is making as it makes its way through the restriction.

3. Coolant was changed to a "Dex-Crap Safe" coolant when I did the water pump, but have noticed some very minor and minimal "sludging" under the radiator cap, normally seen from mixing dex-crap and regular coolant.


Jay

[Jongo88]

Back flush it and you will be good to go...

[Stevonator]

In that case...I agree....sounds like it's time to backflush it.

[87wildside]

Light it on fire, you'll have heat and won't have to fix it.

[Jay-Sliver]

I like Eric's idea the best. I'll have to see if the boss has any "faulty" tractors layin around that he wants to get rid of. They could be the cause of the fire, and my truck just happened to be beside it when it all of the sudden out of nowhere completely went up in flames and took my truck with it.

Jay

[csl2006]

back flush the hoe. I've had to do this 3 times after my dexcool swap to prestone. Point the truck on a slight downhill facing. I just use a water hose with a high pressure nozzle and stick it in the hoses. Undo the hose on the neck and behind the altenator. Might wanna cover the alt with a baggy of some sort. But ya simple fix..easiest one to try. Pisses me off when that happens but it hasn't in awhile now thank god. "where'd the heat go george" I dunno i've been drinkin

[Jay-Sliver]

Ok, so, Update for all thos interested. I didn't do a damn thing and the problem fixed its self. I like them kinda problems. Im still gonna flush it tho. Its never been done.
Um, so for the next question....I only looked real quick, but, do these GM Factory rads have a drain cock on them? I did notice that the lower rad hose connects about a third of the way up, which I thought was just plain old gay. Im sure there's a reason for it tho. When I do the heater core, im gonna do the rest of the system again aswell. Last time I unhooked the lower hose from the waterpump, cus I was doin the waterpump anyways.

Jay

[Hammer Head]

Yes, they have petcocks. It's just easier to pop off the lower hose.

[Jay-Sliver]

is that what the little nub is, on the Passenger side tank. Must be a little o-ring sealed phillips head drain screw in there or something eh?

Jay

[csl2006]

thought they were the square holes

[Jay-Sliver]

UPDATE - Fixed it. Had an air lock. Jacked the front end up, put my coolant funnel on it, and ran it. Coolant started to overflow into the coolant funnel as it should, and then one big burp of air. Oh, I put another rear u-joint in it at this time too. The one cap was seized. Other 3 caps were fine. Stupid GM Replacement non greaseable u-joints. $20 aftermarket greasable FTW.

Jay

[Danzcameo]

Sometimes Jay I've found my 01 blazer will not go from hot to cold, or cold to hot-but if I turn the temp knob from hot to cold slowly or vice versa
it will work correctly again. it does'nt do it often but once in a while.


I think the people who assembled our gas gauges also assembled our temp control's - LOL:) quality

[Jay-Sliver]

LOL. yea, I tried screwing around with the controls, got nothing. I deff. had an air lock, that was very apparent. Got great heat now, and no more gurgling in the heater core either.

Jay

[Danzcameo]

So you burped it-LOL glad its working correctly again-your gonna need that heat soon enough.

[Jay-Sliver]

I've needed the heat pretty near all summer long. Its been stupid cool up here all summer long. It's freakin retarded. Its half decent during the week when I gotta work, and come the weekend, its rain all day both days when I wanna go hop on my 2002 YZ125 Moto-X bike. Grar..

Jay

[Danzcameo]

Thats Murphy's law for ya,if you ever meet up with Murphy tell him I'm gonna beat the Crap out of him cause hes ruined many a good plan on us! LOL

[Jay-Sliver]

LMAO, will do.

Jay

[Danzcameo]

hahahaha-:D