EinST

I think you SHOULD "stop thinking about this" and make her happy. Anyway, you made me read through this entire sordid thread again. One thing I don't understand is when you said "hot coolant splits somewhere and most goes through the radiator and back through the thermostat to the pump." The direction of the coolant flow should be from the hot block, through the thermostat, and toward the radiator. Either you have some weird setup or the water pump is turning the wrong way. What's the 8th of your VIN?

kevinkpk

EinST is correct, the bottom hose supplys coollent to the engine, when up to temp, the tsat opens allowing that flow back to the radiator. Without a tstat you are not restricting the flow enough to allow the coolent enough time in the radiator to cool. The bottom hose will always have coolent in it. One ? does the bottom hose have an internal spring or is it a universal replacement? It could be it is collapsing on you. Thats ONE important thing to check. In other words does it look like one of these with the external ribs?
Radiator Hose : Flex Radiator Hose : Universal Radiator Hose

BW56

It runs 150*ish with out the t stat. Its got the stock smooth hose with the spring inside, looked good, checked it when i replaced the radiator. The hot 1" line comes from the right side of back of the of block somewhere to the external t stat housing past the spring on the t stat on to the pump. The main hot line comes from the left side of the head (a 1/2" line splits off going behind the block to where only god and gm knows where) to the radiator inlet, out to the front of the t stat and on to the pump. When the wife gets home i'll look for the vin #

BW56

Vin# 1G1JF52"4"5...... The wife laughed out loud for real when i told her you said i should make her happy. It was nice to hear her do that. Thanks we needed that.

EinST

Okay, so you have the old OHV 2.2L motor, I had to make sure. The general coolant flow is through the thermostat, the lower radiator hose, radiator, back through the upper radiator hose. The smaller diameter hose that tees off on the hot side of the thermostat is the heater hose that feeds the heater core. The other smaller diameter hose that tees off of the coolant pipe on top is the outlet side of the heater core. This setup eliminates the coolant bypass line (allows some circulation before the thermostat opens). In your case, I think the heater core is plugged up which causes no or insufficient coolant circulation to kick-start open the thermostat. Do you get any heat inside the cabin?

BW56

YOU have cleared the muddy water. Just made a Pepsi run with the heater on, eh so so. Water temp was around 150* so not great heat BUT i have an old trick to try. Saturday Ill bypass the heater core by running the Teed off top line directly back to the t stat housing and install the working t stat. If it works it is a partially plugged heater core. And i'll go on from there. Thank you for giving me hope.

EinST

It's sounding more and more like the heater core, then. One more thing, I got conflicting information from different sources and thus had to double-check on the coolant flow direction. You were correct in saying "hot coolant splits somewhere and most goes through the radiator and back through the thermostat to the pump." The coolant does flow out through the upper radiator hose, radiator, lower radiator hose, and then back in through the thermostat. What opens the thermostat is the hot coolant from the top heater hose through the heater core into the manifold inlet just behind the thermostat. I can't help but scratch my head and think how it's one of those clever but asinine designs. Keep this in mind if you decide to back-flush the heater core.

BW56

When i took the old radiator apart it looked like kitty litter stuck in the row ends, starting half way down, more as it got lower and looked totally plugged at the bottom. I can imagine what the heater core looks like. Is there a chemical flush that would help when i back flush the heater core? Or just use lots of water?

EinST

It's basically some sort of organic precipitates and thus I've heard the cascade powder or another dishwasher detergent with a tiny red ball in the middle work well. Back-flush as much of the loose stuff out first. If it doesn't work out, probably look for another car? Heater cores are usually pretty inaccessible.

BW56

Success!
Bypassing the heater core with 20" of heater hose and one of the original hoses(for the elbow)the car ran at 195* in stop and go city traffic for a 20 minute drive AFTER getting up to temp before leaving. Shut it down to shop and when i started it up after 20 minutes the temp was still good, it was creeping way up after shut down lately. This proved even a partialy plugged heater core will make this car over heat.

I back flushed the heater core using 2 12" sections of heater hose empting into a bucket to catch the bigger crud. Sent shock waves through it by kinking the hose rapidly many times. Boy did it catch crud. I mixed Cascade and Lemishine in a bucket. Both are for dishwashers and used together. Lemishine says for hard water. This works great in our dishwasher with the hard water build up we had. Filled the heater core for 1 hour and flushed with fresh water some more. Did the same with CLR and flushed. Im soaking some of the material i pulled from the old radiator in a cup of each as the heater core is soaking. After 6-8 hours i've seen nothing happen to the test material. Oh well, I still flushed the heck out of it.

I have since put everything back as it was in the beginning. After the test run its still running At 195* +- a needles width. As it did before all this started. And no creeping up in temp when shut down.

Thank you to everyone for your comments and suggestions. I hope what i have gone through and learned will help others.............
Bob W.