: would bad hg's cause the lower radiator hose not to get warm??



pontiacsouth
05-11-09, 02:57 PM
would bad hg's cause the lower radiator hose not to get warm??

just wondering....

Submariner409
05-11-09, 04:14 PM
Coolant circulation problems cause the lower hose to stay cool after warmup and (maybe) thermostat - open.

Coolant circulation problems are caused by insufficient coolant, bad thermostat, no thermostat, clogged radiator and/or hoses, and a malfunctioning water pump.

Until the entire Northstar cooling system gets to over 188 degrees the lower hose will stay cool. Only after engine block coolant above 188 degrees starts to flow through the radiator will the lower hose begin to warm up. ??? If the radiator were 100% efficient, the lower hose water would return to the water pump at ambient air temperature.

pontiacsouth
05-12-09, 07:42 AM
Coolant circulation problems cause the lower hose to stay cool after warmup and (maybe) thermostat - open.

Coolant circulation problems are caused by insufficient coolant, bad thermostat, no thermostat, clogged radiator and/or hoses, and a malfunctioning water pump.

Until the entire Northstar cooling system gets to over 188 degrees the lower hose will stay cool. Only after engine block coolant above 188 degrees starts to flow through the radiator will the lower hose begin to warm up. ??? If the radiator were 100% efficient, the lower hose water would return to the water pump at ambient air temperature.
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well, my car overheats and the lower hose is still cold. the upper is really hot. took it to the shop and they said its the hg's that are bad. i changed the stat and took the surge tank off & cleaned it, made sure the bypass/crossover tube is clear, water pump & belt are ok, stuck a garden hose in both radiator outlet/inlet and ran water thru it. All the hoses dont seem to be clogged. the old stat had some kind of rubber seal that was attached to the stat, not the gasket that goes around it, but it was like a diaphram or something. some of that was broke off, could that get stuck in the engine and block the flow?

i just wanted to know if the shop was just trying to screw me or if the bad hg's would make the lower hose stay cold.

thanks for the info sub....

Submariner409
05-12-09, 07:59 AM
The usual sequence with bad headgaskets is: The gasket fails at one or more cylinders due to either head bolt clamping loss or gasket cylinder seal ring failure. (The Northstar is an Open Deck block design, so there's precious little seal surface around most of each cylinder liner.) The harder the engine works, the more cylinder combustion gas blows into the water jackets, pressurizing the system over what it's designed for. Coolant blows off through the surge tank cap, causing water pump cavitation and no coolant flow. It is also possible to lose coolant to the bad cylinder(s) while the engine is off. In those scenarios the lower hose will stay cold even as engine block temperatures go through the roof, compounding the problem.

bigtone
05-12-09, 08:03 AM
When my headgasket went the temp would spike up going up a hill. When I would pull over, even though the display said 245 or so, the radiator was cool, both fans would be running. I think the system was getting airbound after the combustion gas displaced the coolant, and the water pump would stop circulating. Was a tiny spot on number 1 cylinder where the gasket was leaking.

pontiacsouth
05-12-09, 10:18 AM
When my headgasket went the temp would spike up going up a hill. When I would pull over, even though the display said 245 or so, the radiator was cool, both fans would be running. I think the system was getting airbound after the combustion gas displaced the coolant, and the water pump would stop circulating. Was a tiny spot on number 1 cylinder where the gasket was leaking.

ya, that makes sense, air doesnt cool very well. my radiator is cool as well, with both fans running. i tested the car for combustion gasses in the antifreeze and it didnt turn yellow, sort of blue/green, tires plus tested it and they said it was ok, then i took it to the shop where its at now and they said it was positive.

anyone want a very nice bronzemist '01 dts??

bigtone
05-12-09, 11:54 AM
ya, that makes sense, air doesnt cool very well. my radiator is cool as well, with both fans running. i tested the car for combustion gasses in the antifreeze and it didnt turn yellow, sort of blue/green, tires plus tested it and they said it was ok, then i took it to the shop where its at now and they said it was positive.

anyone want a very nice bronzemist '01 dts??
Whereabouts are you located?

pontiacsouth
05-12-09, 02:37 PM
Whereabouts are you located?

central wisconsin

bigtone
05-13-09, 07:40 AM
Thats too bad, I'm in PA. I would be interested if you were closer.