like the title says if the heat is set to 90 it will blow hot air from the vents find but soon as i stop at a light and the engine drops down to idle rpms it goes cold. Then when i start moving again it gets hot again any ideas i checked my coolant its not low im baffled.

 

It could happen if you get air into the heater core. Did you flush your system lately? Burp it?

Raise the front of the car and run it for like 10 minutes. Lower it back down and see if you need to add more water. You'd be surprised how much better your heater would work after this.....if that was the problem.

 

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try bleeding your coolnt system. if not, most likely your core. good luck, its a ***** to rip out.

 

oh gees i don't like the sound of that. i was actually going to get my system flushed. thanks guys

 

You probably have air trapped in the cooling system. It has been discussed here before.

Similar thread:
https://my350z.com/forum/maintenance...in-motion.html

There's an air relief plug on one of the heater hoses in the engine bay.

DE air bleed on passenger side.


The HR air bleed is on the driver side under the upper right corner of the engine cover.

DE FSM: http://www.nicoclub.com/FSM/350Z/coupe/2005/co.pdf
HR FSM: http://www.nicoclub.com/FSM/350Z/cou...oadster/CO.pdf

 

Wow thanks I will have to give that a try the car is a 04.5 with 53000 miles I didn't figure the heater core was gone. But weirder things have happened.

How do you use that let the car idle up to temp then crack it a little

 

Yes, or you can get the spilless funnel for the radiator cap. Pinch the coolant hoses off and on a bit as well. Finally, check to make sure the overflow container has not run dry and is at the proper level.

 

Sounds good I will give it a try