Malibu heater issues

[honoredprince]

GOt a 2018 Chevrolet Malibu Hybrid and my heater only works when the engine's running, once it switches to battery, it blows cold. Ive topped off the coolant, changed the thermostat and even tried swapping the auxiliary heater core. Before I tear into the dash or replace the aux pump, has anyone run into this and found a simpler fix?

 

[thomas.burke]

That aux pump is usually the problem on these hybrids when the heat cuts out in EV mode. If it's weak or not running at all, the coolant won't circulate right when the engine's off.

 

[Dimples1]

GM hybrids skimped on proper electric cabin heat, if your 2018 Malibu Hybrid only warms when the engine runs, it's likely a design flaw, not a failed part. Many owners chase fixes that don't exist.

 

[honoredprince]

That aux pump is usually the problem on these hybrids when the heat cuts out in EV mode. If it's weak or not running at all, the coolant won't circulate right when the engine's off.

Makes sense. I was starting to suspect the aux pump but wasnt sure. Did you end up replacing yours yourself, or is it better to have a shop handle it? Also, is there an easy way to test if its running or weak without pulling everything apart??

GM hybrids skimped on proper electric cabin heat, if your 2018 Malibu Hybrid only warms when the engine runs, it's likely a design flaw, not a failed part. Many owners chase fixes that don't exist.

Fair point sir, i've heard some people say the electric heating just isnt enough in these models. So if it's more of a design limitation like you said.