Check the coolant level first. When the engine is cold remove the radiator cap and look to see if the radiator is full. Top off as necessary. If it is full than there is a chance that the heater core is plugged and needs the extra RPMs from the engine to push more coolant through it. Heater cores can be back flushed and this should be tried before considering replacement. Back flushing works about 90% of the time.
If it does work I would recommend flushing the cooling system. Dirty coolant can cause the heater cores to plug up and you don't get a second chance if the heater core plugs up again, typically.
I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa
Answers & Comments
Check the coolant level first. When the engine is cold remove the radiator cap and look to see if the radiator is full. Top off as necessary. If it is full than there is a chance that the heater core is plugged and needs the extra RPMs from the engine to push more coolant through it. Heater cores can be back flushed and this should be tried before considering replacement. Back flushing works about 90% of the time.
If it does work I would recommend flushing the cooling system. Dirty coolant can cause the heater cores to plug up and you don't get a second chance if the heater core plugs up again, typically.
I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa