plymouth voyager heater problem

[cerv]

1994 voyager: Heater blows out cool air when engine rpm slows down. Gage is ok...replaced thermostat...flushed heater core...filled fluid. Any other suggestions?? Vacuum?? Any other suggestions would be appreciated.

[tempfixit]

Originally Posted by cerv

1994 voyager: Heater blows out cool air when engine rpm slows down. Gage is ok...replaced thermostat...flushed heater core...filled fluid. Any other suggestions?? Vacuum?? Any other suggestions would be appreciated.

Make sure all the air is out of cooling system. Keep on checking coolant level in resorvoir after each warm up and cold down cycle. You could put vehicle on incline and run engine with radiator cap off and heater temperature turned on full heat and fan sitch on to get the air out of system. DO NOT open radiator cap on a engine that is at normal operating temp.

[jrozanc]

Our 1998 Plymouth Grand Voyager (3.3L) had the same exact problem. It wasn't keeping coolant, replaced thermostat. Turned out water pump was shot.

[chad millett]

Ive seen the fins in the water pump corroded and it causes the cooling system to lack circulation especially at low RPMs.