Well, I'm worried. My heater died, this bothers me for two major reasons. 1) I am supposed to be taking a long trip here in a week and 2) The only reason for no heat coming out of the vents that I have heard of (on here) was someone who had a blown head gasket.

The fan works fine, the direction of the air seems fine (it changes to defrost and floor and dash) but it just blows outside temperature air in.

Maybe it's a coincidence but It seemed like it died right when I put my window down (power windows) Do you think there is a shared fuse or something?

Is there a valve that turns on to allow the water to go thru the heater core that may have died?

I hope my head/head gasket is okay.

 

Not to ask a dumb question, but does the **** to adjust the temperature still feel the same? I had a buddy that had the **** shear off, you could spin it, but the stud it was supposed to turn didn't turn. He was a ham fisted moron, and didn't realize what was wrong. Could be worth checking, maybe you just need a new ****. Also in the same vein of thought, I'm not sure how that particular **** operates on a 98, could be a broken/suck cable.

There shouldn't be a fuse to control the heat if it is blowing the correct place.

 

Check the radiator water level first.
Then see if the "Blend Door" is opening.

 

I just ran out and checked my oil; there doesn't seem to be any water or foamy stuff in it. However my radiator overflow was empty. I didn't check the actual water level because the truck is still pretty warm from driving.

Now I am even more worried. THe last few times I have started it I have seen some white/gray smoke coming out and I have been writing it off as condensate since it has been colder outside. However, I just started the truck (about 15 minutes after an hour drive, so the truck was still pretty warm) and there isn't any white/gray smoke when I start it but when I rev it a little I get the usual black puff with some gray/white behind it.

 

I'm assuming it's the flapper that varies the amount of cold/hot air.

I don't think this is it because I didnt' touch the temp control before the problem but when I turn the **** now it feels fine.

Is that amount of grey smoke okay? Tell me I'm just paranoid.

 

First the water is constant flow. There is no valve like on a 1970 nova that opens and closes the flow of fluid to the heater core, it constantly flows through the heater core. Second the door that controls the cold/hot air mixture from the a/c evaporator and the heater core is manual. It comes off the temperature control via a cable to the top of the heater-a/c unit under the dash. You can remove your glove box and see the cable inside and to the left. I would say that it was just a coincidence that the heat stopped when you opened your windows.

You are looking at roughly three possibilities: 1. clogged heater core. 2. Low coolant 3. Air mixture door.

I would say it probably is not number 1 as you said that it happen at the same time you opened your window, meaning at one time. As the core clogs and has less flow the heat level goes down but not immediately. I would say that it is not number 2 as if your coolant is low and was not an abrupt loss you propably should have heard a running water sound under the dash when you start the truck from the water pump filling up the heater core. I don't know how low the coolant has to be before coolant does not reach the heater core period.
I would be more inclined to check the mixture door/cable/control. The door opening or closing would be the only thing I can think of that would cause an abrupt change in air temp. Joe

 

I treated three trucks for similar symptoms last year. The heater core gets blocked fairly easy. I bought a jug of rad flush, soaked and back flushed just the core and I got all my heat back and then some! It worked so good I did two other trucks for buddies and all our heat came back.

I used a filtered funnel for the flush so I could see what got flushed out and the predominant debri in all three trucks was copper colored silicone chunks.

 

just to have a word to say but i was reading all the posts and responses but i read that u had said that there is whitish grey smoke that says posible head gasket or crack in the head and yes if that is the case i will not have heat.look at your temp gage if u have one and if u are blowing whitish smoke release your rad cap just a bit to release the pressure and u might find u will get some heat back.

 

The problem with the heater was low coolant. I put just over a gallon back in to refill + some extra in the overflow tank. I also put in a bottle of Bar's Leak to hopefully help any small leak. The road I travel has a very, very steep hill that I come down. This is where the heater stopped working, which makes perfect sense.

However, I'm not sure where I am loosing water to yet. It doesn't seem like my coolant level has went down any since I refilled it and I have driven about 250 miles.

 

I feel good now, the reason for the leak was a leaky hose; not a biggie.

 

Thanks for the update......