99 Camry overheats after heater core replacement

[sabbates]

All-

The heater core on my 99 camry was leaking, so I ordered a new one from Rock Auto.

I installed it, but when I turned on the car and turned on the heater to check for leaks, the car started to overheat. The core didn't get hot, and the air coming out of the blowers was cool, so I don't think the coolant was circulating through the core.

I thought maybe I had the inlet and outlet hoses mixed up (does it even matter?), so I reversed them, but still it over heated.

I disconnected the hoses at the firewall and installed a bypass pipe, so the inlet hose is connected to the outlet hose, bypassing the core.

The car didn't overheat this way.

What do you guys make of this?

Is my new core clogged?

[Pauloil]

You need to bleed system by running motor with rad cap off and watching the air bubbles leave.

[JohnGD]

Usually that's a sign of air in the system. But you can double check by connecting a clear PVC hose inline. I didn't want to suggest tap water and hose however.

[sabbates]

Why did it fix itself when I bypassed the core?

[JohnGD]

Maybe the air in the system worked its way out. When something like this happens after working on the cooling system it's air not purged. Is the radiator full now? Check only when cold. Usually you hear several seconds of gurgling sound and the air is all cleared out.

Do you have an OEM thermostat or a Stant OE-Exact with a jiggle valve in there?
(you can see the jiggle valve on this one)
http://www.rockauto.com/catalog/moreinfo.php?pk=1145694

If you hook up the core again and the overheats then I'd double check the heat core itself.

[Pauloil]

Just be sure to bleed and replace 50/50 fluid

[tony_2018]

Hey OP how did you overcome those metal bands that were on the pipes connected to the the heater core. Did you need a special tool? I'm getting ready to replace my moms and when I saw that I didn't know what to do. Please let me know. Thanks man.

edit: just realized you might be thinking of the clamps that were holding the pipes to the blower box, no it looks like a metal ring around the heater core pipes.