no heat at idle

[otgarza]

Working on a 05 M35 and it blows cold air at idle, as soon as you drive the heat kicks in. Once you come back to a stop it comes out cold again. What are a few things to look at?

[svard75]

Search man!!! It's likely air in the heater core. Burp the coolant until it starts to work again.

[otgarza]

Did a google search but no one ever says what worked and what didnt. How is this system burped...thru the radiator or does it have a bleeder

[svard75]

Fill rad when cool, run car with heat on max till NOT then let cool refill rad, repeat till rad level max and overflow bottle is at full hot line.

[jiggersplat]

I ended up having to have my heater core flushed.

[svard75]

That's pretty extreme. How did they do that?

[jiggersplat]

Dunno. All I can tell you is they bled it before I took home the first time after the radiator swap. I bled it. They bled it again and it still wasn't right. What I can tell you is that the customer waiting area had a Keurig machine and cookies

In retrospect, the time the radiator blew was the first time I think I had the heat on this season. I wonder if a clogged heater core was causing extra pressure in the system which caused the radiator failure.

[svard75]

Could be continual use of tap water that led to corrosion and calcium buildup. Why did the rad blow? Or was it pipes that blew?

[jiggersplat]

It was the bottom seam where the plastic is joined to the metal.

[EdBwoy]

It was the bottom seam where the plastic is joined to the metal.

Typical Nissan radiator problems

[EdBwoy]

Working on a 05 M35 and it blows cold air at idle, as soon as you drive the heat kicks in. Once you come back to a stop it comes out cold again. What are a few things to look at?

I'd also say look for coolant leaks around the rad hoses and under the car. But if you recently did some coolant service, definitely burp it as said above first.

[Findmorefire]

Working on a 05 M35 and it blows cold air at idle, as soon as you drive the heat kicks in. Once you come back to a stop it comes out cold again. What are a few things to look at?

I had a problem similar to your and I searched and search for a answer even from technicians that I trusted . Turns out I had to replace A/c relay on my M35 that was located behind fuse box.
Test relay or just replace if not to costly.

[Findmorefire]

Working on a 05 M35 and it blows cold air at idle, as soon as you drive the heat kicks in. Once you come back to a stop it comes out cold again. What are a few things to look at?

Disregard my last message . I just realized you have a heat problem . I had a a/c problem . Good luck trouble shooting.

[Ilya]

Working on a 05 M35 and it blows cold air at idle, as soon as you drive the heat kicks in. Once you come back to a stop it comes out cold again. What are a few things to look at?

Disregard my last message . I just realized you have a heat problem . I had a a/c problem . Good luck trouble shooting.

You bumped a 2yr old thread...pretty sure there is no troubleshooting being done.

Welcome to the forum regardless .