Heat in the Tahoe's been luke-warm / fair at best all winter. Temp gauge also never climbs above the line that would be ~140 degrees on the factory cluster.
One school of thought is that the thermostat in the truck is either stuck partially open or it's maybe way too cold of a thermostat...160 degrees or similar. Cheap and easy enough to replace, I'm just going to do it.
So I'm staring at the heater control valve which sits between the firewall and water pump / engine. It has a solenoid with mechanical linkage, when a vacuum is applied it opens the internal gate to allow coolant into the heater core.
Does this valve open progressively as more vacuum is applied, as the dash control is dialed over towards max heat? Or is it all or nothing and the "blend door" down under the dash actually controls the heat felt in the cabin?
Could it be that whatever is applying vacuum to that solenoid isn't applying enough to open it fully? Or maybe the solenoid itself isn't opening, it's old/hanging up internally....and not allowing a full flow of coolant to enter the heater core?
Blend door....what exactly does it do and how does it work? Blending outside air in with the heat coming off the core or ?
And lastly the heater core itself....if it's partially clogged, I was wondering about just disconnecting the hoses at the heater control valve and trying to flush the core out directly. I've heard vinegar and water do a good job of cleaning out scale and muck. Or maybe buy some of the heavy duty cleaners they sell at Napa?
Looking for input or better yet, diagrams out of a shop manual that might make life easier.
One school of thought is that the thermostat in the truck is either stuck partially open or it's maybe way too cold of a thermostat...160 degrees or similar. Cheap and easy enough to replace, I'm just going to do it.
So I'm staring at the heater control valve which sits between the firewall and water pump / engine. It has a solenoid with mechanical linkage, when a vacuum is applied it opens the internal gate to allow coolant into the heater core.
Does this valve open progressively as more vacuum is applied, as the dash control is dialed over towards max heat? Or is it all or nothing and the "blend door" down under the dash actually controls the heat felt in the cabin?
Could it be that whatever is applying vacuum to that solenoid isn't applying enough to open it fully? Or maybe the solenoid itself isn't opening, it's old/hanging up internally....and not allowing a full flow of coolant to enter the heater core?
Blend door....what exactly does it do and how does it work? Blending outside air in with the heat coming off the core or ?
And lastly the heater core itself....if it's partially clogged, I was wondering about just disconnecting the hoses at the heater control valve and trying to flush the core out directly. I've heard vinegar and water do a good job of cleaning out scale and muck. Or maybe buy some of the heavy duty cleaners they sell at Napa?
Looking for input or better yet, diagrams out of a shop manual that might make life easier.
