[Wejl]

Sometimes, not all, when the truck warms up it blows cold air. We turn the heater control totally OFF for 30 seconds or so and turn it back on, and suddenly we get heat. I may have to do this a few times! I asked my local mechanic and he said maybe the heater shut off "doors" are not opening and closing properly? The other day we went out in the truck and it was working just fine again. It's intermittent. I havnt checked anything as yet, such as coolant etc. Is it a possible air lock. I've read many of the heat problems today on your forums, but none of them described this particular issue. If it's a costly fix then we now are thinking that after driving this great little truck for 10 years 100% trouble free, that maybe it's time to trade it in !!

 

[2013GV]

More than likely a sticking blend door or door actuator. If the heater core was air locked you would know it as there needs to be flow through that to get the Thermostat on the engine to open.
It could be a simple matter of a syringe and some lube on the pivots. Not an uncommon fault Getting access is annoying and requires bits if internal trim removal, and contortions into un natural positions.

 

[2008GV.JB424]

Sometimes, not all, when the truck warms up it blows cold air. We turn the heater control totally OFF for 30 seconds or so and turn it back on, and suddenly we get heat. I may have to do this a few times! I asked my local mechanic and he said maybe the heater shut off "doors" are not opening and closing properly? The other day we went out in the truck and it was working just fine again. It's intermittent. I havnt checked anything as yet, such as coolant etc. Is it a possible air lock. I've read many of the heat problems today on your forums, but none of them described this particular issue. If it's a costly fix then we now are thinking that after driving this great little truck for 10 years 100% trouble free, that maybe it's time to trade it in !!

Might not be any help but how about a radiator flush? Turning the heat off and on for 15 minutes in 10 second intervals while performing a flush might help loosen something up.

Don't be afraid to tell me if it's a silly idea 😀

 

[2013GV]

Might not be any help but how about a radiator flush? Turning the heat off and on for 15 minutes in 10 second intervals while performing a flush might help loosen something up.

Don't be afraid to tell me if it's a silly idea 😀

Nope, good idea on a water controlled core but the heater core in these is constantly in circuit, thats where the thermostat gets its sense supply from to open as engine warms up. These have an aur blend door that opens and closes to control heat, fully shut stops air over the core, fully open, you're growing tropical fruit in the cabin.

If his engine was over heating and thermostat was not opening but tested ok, then the core needs a flush.