QUICK IDEAS PLEASE: Overheating Suburban but no heat

[Goat Roper]

And no, it isn't the thermostat, we just replaced it.

Up in MN and the '96 Suburban sat outside last night and it got bitterly cold. Started it up this morning, no heat but overheats. Had local store open up so we could get a new thermostat (first logical thought) but same condition exists.

Trying to get back home today, what else should I look at??

Thanks in advance.

[Yooformula]

water pump? clogged heater core? big ass air pocket?

[Reverend Cooper]

well it it has no heat there is no coolant in the heater core,or the hot water valve is not opening to let hot coolant in, is it literally spewing coolant out of the overflow when it over heats? if not is it poss. just a bad temp gauge, sounds like maybe if there is no heat in the the car it has a air pocket in the system from lack of coolant, so my thoughts are if there are no leaks check for a bad radiator cap or compression getting into the system i/e headgasket good luck

[Goat Roper]

Little more info;

When vehicle shows that it is overheated and you shut it off it starts to fill the overflow. When you turn the vehicle back on it sucks it back in.

You can certainly hear a fair amount of gurgling though when you shut the truck off.

[pickardracing]

Headgaskets gone.

[Goat Roper]

Resolved.

Massive air pocket from the thermostat being removed, lost more coolant than I thought but it was enough to cause my issue.

Sorry for the panic mode but when you got a 7 hour drive in front of you and a truck full of kids with 0 degree temps I want to make sure I got this right.

Thanks all.

[Reverend Cooper]

get the cap off,heat up the truck and have the heater on also let it run till it drawsa the radiator low speed up rpms,fill radiator and cap it off,make sure res. is at the right level.

[juicedimpss]

it helped to jack the front of my truck up when i bled mine.

[lordairgtar]

If you can locate the highest point of the cooling system, usually a heater hose, put on one of those T valves in that have the screw on cap. When ever you install new coolant or add coolant, keep that open so air can find it's way out. Air will seek out the highest point to escape. As you fill through the radiator cap, you can replace the cap on the hose. You need that cap closed before it get too hot.

[indyzmike]

Good that you got it fixed. It sounded like a classic example of not having enough anti-freeze and the radator/hoses freezing up. If the thermostat sticks shut you would have had heat from a hot engine. Make sure you got enough juice in there.

[pickardracing]

If you can locate the highest point of the cooling system, usually a heater hose, put on one of those T valves in that have the screw on cap. When ever you install new coolant or add coolant, keep that open so air can find it's way out. Air will seek out the highest point to escape. As you fill through the radiator cap, you can replace the cap on the hose. You need that cap closed before it get too hot.

This is prime advice.

[Goat Roper]

Thanks for the info guys.

Found the culprit this morning, it wasn't an air pocket. It was the fact that I had the coolant flushed/filled by a shop on Friday and the mix they put in was too weak. What I thought was an air pocket yesterday was in fact due to the lines finally thawing out and coolant flowing. I even asked what the coolant was rated at and the reply was -35.

I know this because when I went to look at the coolant this morning it was a heavy slush, and that was at around 5 degress (or whatever it was this morning), it was -5 in MN yesterday.

Pissed, yes, taking it in to them this morning.

[indyzmike]

Lucky you are not replacing a radiator or, worse yet, an engine block. It sounds like the person that refilled your coolant did it the lazy way. They probably flushed the system with water and then topped it off with 50/50 mix. This does not take into account the water that is left in the block. The correct way is to flush the system, add 1/2 of the system capacity of antifreeze, then top off with water. Mike

[Goat Roper]

I am pretty damned sure you are right.

[pickardracing]

Yet another instance of why i either do the work myself, or take it to a mechanic that I KNOW has the expertise to do the job correctly.

I'd rather pay more for a good tech than save money and let idiots work on my shit.

I'd take it back wherever it was done and jam it up their asses.