Omar46

So recently I have noticed that my heater won't warm up if I'm at idle. When I'm driving the heater works perfectly fine. My brother had the same problem in his 350z and he changed the thermostat and it solved the issue. Do yall think that will also solve my problem? Has anyone else had similar experiences?

Billman250

99 percent chance low coolant due to small leak.

Omar46

No leak, and coolant is topped off.

Slowcrash_101

Might need to bleed air out of it?

windhund116

Bleeding should do it. May need to do it several times, to remove all the air in the system.

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Car Analogy

That is the classic symptom for air in the cooling system. The other symptom is an overheated engine resulting in a warped head. So its not something to ignore.

Its not easy to bleed the system fully. Keep at it until heat at idle is back.

Slowcrash_101

Just a little tip I discovered, I found that just putting a long funnel on the radiator snout, and just running the car with the radiator cap off, is enough to prevent any spills. Also if you just keep squeezing the radiator upper hose with the car running you will see bubbles come out through the coolant in the funnel, and funny thing is once no more bubbles came out from me squeezing the hose repeatedly, the air coming from the heater was scalding my fingers.

I still cracked the bleeder open after I turned the car off just for peace of mind and no hissing just straight fluid gushed out. So I ran the car again, squeezed some more, with the funnel in the snout, half of the funnel full of coolant, no bubbles in the coolant when I squeezed and then the heater air was really hot, and I'm like bam, I just learned an easy way to bleed the system.