A call to the common sense here. The automotive forums seem filled with confusion.
I have a vehicle that displays a "common" deficiency of no heat at idle. (It's been fricken cold here lately)
Yet, the heat is just fine when the engine is turning over 3000 rpms. (sport mode driving! ;-)
Scouring the web, it appears this issue is familiar to many, with a frequent call to repalce the heater core. Some reports indicate 3 replacements in as many years, and some owners of similar cars get the heater cores flushed "professionally" every year. $$$
My question is, if the heat core can output good heat when the engine revs are high (read, coolant flow is sufficient) how can replacement of the heater core be the appropriate resolution? It seems to me that increasing coolant flow would be the correct response.
Now, I can agree that if the heater core were restricted, the resistance to flow would limit heat exchange. but doesn't the the high RPM condition prove that the flow through the core is possible? ( the math would support pressure/restriction = flow)
I've never seen such issues with "older cars", with simple coolant flow shut offs and fan speed to control cabin temps.
What might be a solution? An auxilliary pump to improve flow through the heater core?
ps. flushing the core shows free flow in both directions with very moderate pressures. to say the "core is plugged" would be in direct conflict with evidence.
Also, the trouble appears to be wide spread, if the internet postings are sampled, with many varied attempts at a cure.
So is it a new core? citric acid for 6 hours, or add a pump to boost flow through the core?
Also, Does anyone have a comment regarding "vacuum filling" of the coolant system? this vehicle is notorious for difficulty in bleeding the air when refilling the coolant system.
TIA
Cal
I have a vehicle that displays a "common" deficiency of no heat at idle. (It's been fricken cold here lately)
Yet, the heat is just fine when the engine is turning over 3000 rpms. (sport mode driving! ;-)
Scouring the web, it appears this issue is familiar to many, with a frequent call to repalce the heater core. Some reports indicate 3 replacements in as many years, and some owners of similar cars get the heater cores flushed "professionally" every year. $$$
My question is, if the heat core can output good heat when the engine revs are high (read, coolant flow is sufficient) how can replacement of the heater core be the appropriate resolution? It seems to me that increasing coolant flow would be the correct response.
Now, I can agree that if the heater core were restricted, the resistance to flow would limit heat exchange. but doesn't the the high RPM condition prove that the flow through the core is possible? ( the math would support pressure/restriction = flow)
I've never seen such issues with "older cars", with simple coolant flow shut offs and fan speed to control cabin temps.
What might be a solution? An auxilliary pump to improve flow through the heater core?
ps. flushing the core shows free flow in both directions with very moderate pressures. to say the "core is plugged" would be in direct conflict with evidence.
Also, the trouble appears to be wide spread, if the internet postings are sampled, with many varied attempts at a cure.
So is it a new core? citric acid for 6 hours, or add a pump to boost flow through the core?
Also, Does anyone have a comment regarding "vacuum filling" of the coolant system? this vehicle is notorious for difficulty in bleeding the air when refilling the coolant system.
TIA
Cal