cooling issue,

[smackzed]

So I've put in the 3rd t-stat since early dec. None were getting up to heat and the last one just totally failed driving last night. temps wouldn't go above 50c/120F or so. No heat from the heater just outside temps, luckily it was a few degrees above freezing.

So put in another t-stat today and it seems to be working, not crazy about it cause it gets up a bit passed 12 o'clock then drops down to 11:30 then back to 12:30 and back down rather than keeping a regular temp.

Anyway, I've checked the upper rad hose maybe a dozen times. It's alkways super soft, like there's no coolant in it and it's just barely warm. Am i just always missing when the t-stat is open?

Also the heater still isn't really gving off heat. It's luke warm. I touch the one hose and it's hot, the other just lukewarm which tells me that the core is plugged. Sound right? If I reverse the lines do you think that might unblock the obstruction (I'll run the out flow into a pail.)

[Diaric]

i think your missing when the tstat opens. the way your stat is operating with the fluctuations, sounds like a cheap stat, my dodge does something similar.
Id try flushing the heater core with a hose and see what sort of floe, if any you can get.
this will give you a visual of whether it flows instead of guessing. heater cores are cheap and not that bad to change on these.

[smackzed]

yeah it is a cheap one. Motomaster so that should tell you something, but hey crappy trash was the only place open on a sunday, I'll give them that. And the delco one I got from NApa only lasted a month. And I haven't been driving much at all sice befor christmas. Haven't even gone through a full tank of fuel on the new motor

It just seems so weird to me that I've checked it so may times and it's never been open. But it's pretty cold out with 70kmh/45 mph winds so it probably won't open too often or for very long.

Good idea about using a hose to check for flow. Coolant costs a lot more

Edit. I tried using some RTV sealant instead of just the gasket this time and I'm wondering if that's why this one is working and the others weren't. Also this one has a spring on it, the other were little compact ones. When I checked rock auto to make sure that I hadn't gotten something weird there was one other stat that had a visible spring but it was nowhere near the size of this one

[NO TREAD ON ME]

Im new to the 6.2, but mine wasnt very warm, so I put a bleeder on it, kinda looks like a funnel with a radiator cap on it, let it run about 20 minutes and it sucked in about
a quart of antifreeze and obviously pushed out air, cant hardly run it on hi now without getting hot in the truck, never checked the temps of the hoses before hand, the cars we work on are prone to get air locks in the system,and thats what we do to burp em,some times we have to raise the front end also to get the air to rise, also is your cable switching it from hot to cold, didnt really look at mine to see if it was mechanical, but on the car I learned how to drive on(a 59 ford) I had to manually open the heater core stop valve? In order to get the water to flow, then Id shut it down once it warmed up outside. Good Luck, NoTread

[happypunch]

Originally Posted by Diaric

heater cores are cheap and not that bad to change on these.

Unless you are like me and break 25 year old brittle plastic pieces when doing it

My old ford explorer was stupid easy to fix, since I was able to do it in 45 minutes and most of that time was trying to get warm from the freezing temps

I had a tough time with the suburban trying to open the heater box to expose the heater core without breaking anything else... At least its not like the newer chevy's where you have to drop the whole dash!

[smackzed]

I've been thinking that maybe it needs to be bled but I always thought that caused an overheat issue. It could be that the thing is stuck on cold. No idea where I'd check that.

[turbonator]

Originally Posted by happypunch

Unless you are like me and break 25 year old brittle plastic pieces when doing it

My old ford explorer was stupid easy to fix, since I was able to do it in 45 minutes and most of that time was trying to get warm from the freezing temps

I had a tough time with the suburban trying to open the heater box to expose the heater core without breaking anything else... At least its not like the newer chevy's where you have to drop the whole dash!

our heater in rattle-puss is so-so, did so much to avoid overheating that is does not even make heat until half way up the big hill at our entrance/exit, and then is only luke-warm.... when the time comes to yank the dash to work on the heater( it is on the list this summer) i am going to put a 1990's jetta heater in, our jetta heater gets so hot and blows so strong that you could drive it on the highway with the window half down and still not be cold, when it blows on the floor the ducting gets so hot it is uncomfortable to touch... and the actual heater box is so small 2 would probably fit in place of the gm one...LOL...

[NO TREAD ON ME]

In my old cars youd just follow the hot,cold cable off the dash, it runs to the heater hose that connects to the heater core and opens or closes the flow of water, they were mechanical, dont know on these, Id have some where Id lube em good and work em back and forth and theyd start (kinda) working again, It helps to have a buddy moving the lever as you say hot/cold as your tracking it down, however with a soft hose, kinda sounds like air in the system, the cars we see that have crappy heat rarely over heat, just crappy heat, and more so at idle, we bleed em for 30 minutes and there on there way. Mine also seems alot warmer with my foot on the throttle, but my CTD is that way also, so just figured thats the way it was.

[NO TREAD ON ME]

Ok went out fired up the 6.2, let her warm up, asked my wife to go outside and rev up the engine while I checked the hose to see if it was soft.... she said tell the guy to buy a coat, Its cold out(10 degrres) I said his defrost isnt working??? So she went out reved it up while I felt the hose.... mine was soft to(thats what she said), but blowing hot air. Made me think while I was jacking with mine, I noticed a giant air leak pushing air out of the airbox while my fan was on. Where my ac lines went in to on the firewall under the hood. I stuffed the cracks with styrofoam and vacume line thinking Ill go back to that and seal it right later, Hate to see a person or a dog cold. No Tread

[smackzed]

I didn't look for the selector wires but I did bleed the rad, I think. parked with nose up hill
removed rad cap and let it run for 15 minutes. went back and filled some more (rad was low from doing the t-stat and I didn't have enough at home to fill at the time) run another 10 m ins went back and filled, let run 10mins and didn't need any more.

Heat no different. One heater hose hot, one hose cold. It is lukewarm, enough that I can drive without gloves on and hopefully enough for defrost. We'll see. was too dark to do much by the time the burping was done