Small coolant leak

[thanu31]

Hey guys...its been a long time since I stepped foot in here but need some help with my mazda3

07 GT with 206000km. Been great but past month or two its been slowly leaking coolant. I usually see a puddle in the passenger side.

Other symptoms...heat only works if I accelerate.

After looking everywhere I finally spotted a wet spot near where I think the thermostat is.

Could this be a case of a bad thermostat? Could a stuck open thermostat cause leaking?

Thanks in advance

[Noisy Crow]

Stuck thermostat, no. Leaking gasket, maybe. You can get dye that will help pinpoint the exact location of the leak.

As for the lack of heat... probably plugged heater core. You can try having it flushed, easy enough to do.

[TheMAN]

not necessarily
low coolant will cause air pockets in the system, which means lack of ability transfer heat to the radiator or heater core.... higher rpm will reduce the size of the air pockets, making heat transfer more possible

a slow leak like this could also be a bad water pump... go look to see if it's leaking