BDE

Hello Everyone:

I recently bought a 2003 4Runner Limited V8 with dual temperature controls (i.e. the passenger front can get hot air while the driver gets cold air.) It also has a vent near the center console rear (to blow on the back seat passengers.)

I have attached a picture of two hoses connecting my engine to two metal tubes which I think go through my firewall to my heater core. The picture shows where the top hose connects to the top firewall metal tube at one end and to the engine at the other, and also where the bottom hose connects to the bottom firewall metal tube on one end and the other end disappears behind the engine after running to the left a bit.

My mechanic connected them like this after I found out that the heater core had been totally disconnected and asked him to reconnect it. According to him, the hose that is on the top takes coolant into the engine and out from the heater core via the top metal tube, and the hose at the bottom takes coolant from the engine (from the water pump) into the heater core via the bottom metal tube.
I have looked up many diagrams on the internet and still cannot figure out if the heater core uses a specific one of the metal tubes for incoming coolant and the other for outgoing coolant. The diagrams I have seen seem to show that the vents for the backseat passengers have their own heater core and I am wondering if one of the metal tubes leads to that one (in which case both the outgoing tubes/hoses from the heater core are somewhere else and not shown at all in the picture.)

Can anyone help me clarify what the two metal tubes lead to and if it matters which one takes in coolant and which one brings the coolant back out?

Thanks,
BDE

rworegon

Your hoses appear to be in correct positions consistent with this picture from here.

BDE

Awesome site, it has some parts that I was having trouble finding even from citytoyota.com! Thanks a lot.