My heater seems to not work when driving at low speed even when the temperature is normal in the engine. I think that the water pump fails to circulate water thru the heater core when the RPM's are down. But get on the freeway and there is plenty of heat.

Anyone else have this problem?

2003 Z MT w/ 96K miles (daily driver).

Tom Stephenson

 

most likely a bubble in ur cooling system. theres a ton of threads on how to fix it hope this helps.

 

Just floor it when you're cold.

 

I LOL'd!!

 

Thermostat?

 

Highly unlikely. Its a bubble in the cooling system I think...

 

Could be a bubble or your water pump. You also could just be low on coolant. My DD just had this problem and even though it wasn't overheating it still would only blow out hot air when it was moving.

Check the simpler things first!

 

Definitely air in the cooling system, try these steps and report back.

https://my350z.com/forum/8027649-post3.html

 

How about medium speed?

 

On a hot day, my air conditioner blows warm air, unless the engine rev's are up and I am driving around.

I am not sure these problems are related.

I took it to a Nissan dealer and they said my problem was caused by a faulty sensor in the heater box. They wanted $600 to fix it. I have not pursued it yet....as I am unconviced.