Heat issues..

[Jay-Sliver]

Well, I figured out tonight, my random lack of heat issues may not be due to what I origionally thought it was. Anywho, quick question..

From the waterpump, there is a heater core line, runs to the heater core. On the other side of the heater core, is a 2nd line, that goes to the upper intake. Now, my question is, what side feeds the heater core, and what side is the return? Does the coolant feed through the pump, to the core, and out to the top of the manifold, or does it get drawn from the upper manifold, through the core, and drawn into the water pump?

On my way home tonight, I slowly lost all my heat. I poped the hood, got out, and felt both lines. The line from the water pump was stone cold, and the line from the manifold was hot....a few squeezes and shakes of the hose from the water pump, and it got hot again and I had heat once again. Im almost wondering if I have either a bad water pump, or some debris in the system floating around or something..

Anywho, im goin to bed.. let me know what ya's think, and how the system works.

Thanks,
Jay

[Big Mack Daddy]

Pretty sure the line from the pump feeds the core and the intake is the return but i could be wrong.

[XTREME80]

It is vise versa, comes from the intake and returns to the pump. Sounds like you may have a stopped up core.

[BigMoney]

It is vise versa, comes from the intake and returns to the pump. Sounds like you may have a stopped up core.

Yup, thats the same thing that happened when my old sonoma's heater core was plugged up. Sure was a pain to change out, too.

[Big Mack Daddy]

See, I said there was a chance I was wrong and that chance was correct. :p

[Jay-Sliver]

Haha, well thanks guys. My other theory is this... compression and or power stroke pressure is getting by the head gasket on the pass side rear cylinder (cus thats the one I had very minor white crusty buildup on when I changed my plugs at 160,000Kms) (223,000 on it now) I am loosing my coolant at a rate which is virtually unmeasureable, and it dont smell nor look like its burning it, and its not in my oil every 5000Kms (3000Mi) So, what im thinking is this compression/powerstroke pressure is slowly filling the heater core with air, creating an air lock. Sometimes when driving, you can hear the heater core gurgle'n away.

Jay

[neo71665]

It is vise versa, comes from the intake and returns to the pump. Sounds like you may have a stopped up core.


I agree

[Jay-Sliver]

I guess I failed to say I pressure tested it, for 3 hours one day, at 14PSI...didnt move a bit..

Jay

[spideyjected]

Good luck. I'd say the heater core would be my first guess.

[csl2006]

if it starts over heating turn your hot air on. see if that reduces the temperature readings. if it does that a pretty good indicator your heater core is plugged up. Try to spray it out with a high pressure hose. spray into both hoses, you'll know right away if its plugged from the water flow coming out but make sure your front end of the vehicle facing down hill. I had to do this 3 times in 3 years and finally it quit plugging up thank god.

[soCAL1stgen]

if yours is like my 91 you can just bypass the heater core. i did it and it works great.

[12sws27]

if yours is like my 91 you can just bypass the heater core. i did it and it works great.

That's a great idea for you and me. Me being in Florida and you in California. But Jay's in Canada! Think about it...It's September and he is already using his heat...LOL!

Jay, FWIW, My Blazer's heat has never worked and I've pulled the hose of and flushed and back flushed it a few times over the 4-5 years I've had the truck. It never works. I flush that b!tch until sparkling clear water it pouring out and still nothing.

[spideyjected]

Isn't there some kind of valve in the line on the second gens? IDK, just trying to give ideas.

[csl2006]

roll it off a cliff and buy a new vehicle. Thats what we do in america, until after you realize while your truck is flipping down the hill that your poor and you live in america and cant afford a new vehicle because they cost 30-40K for a new fvckin truck! propane heater, install it in your truck

[spideyjected]

I got a better idea. Get yourself two BIG girl friends. Set them on either side of you and snuggle up. Them girls will provide more than ample warmth Jay. Coming from a fellow norther climate resident you know that I know what I'm talking about (o;

[csl2006]

he'd have to convert his truck to have the steerin wheel in the cent of the dash...be hard to do. hit a deer, drag it into the drivers seat, slash its belly open and crawl in there for warmth. thats what bear grylls would do

[spideyjected]

I think converting the steering would be easier than a heater core in our case though (o;

[csl2006]

amen to that. move to flordia jay, that'll solve the problem and 99% of users on here are from florida.

[Jay-Sliver]

I wanna move to Florida :(

lol

Jay

[dave1182]

while your blowing out the heater core, check the lines that feed it, are the in good shape, are they brittle or have the colasped, and the flow from the manifold to core to the pump.

[White-V-6-S-Ten]

When you go to blow the heater core out first find out which is the supply and return line and then after you know which is which start by blowing out the return line. Cause that will knock loose what ever is plugging it up if thats your problem.
I havent used my heat since like march i think. I am still using my ac daily cause its friggin hot here. I really hate the heat here. I miss california's weather

[offroadfirstgen]

still cold as **** here

giver her a good flusherou with water through both side of it (just to be safe) and hope to sweet little baby jesus u dont need to rip the heads off.. but in the real world wile ur in there give er some performence upgrades (cam n e one)