Pontiac Grand Prix Forums : Grandprix

Hi guys, I got a question for anyone with a 98' Grand Prix GTP or similar car. Which exactly is the hose the goes to the heater core? I want to install the Prestone Flush kit tee but I don't want to cut the wrong hose. They are both too close to each other for me to be able to tell. Is it always the top one on the firewall? Thanks for your time.

The one that's lower as it comes out of the tensioner would be the one carrying coolant to the heater core.

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2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

Wow this is confusing me even more, cause the one that is lower flows over the top of the top one. Tensioner pulley?

The tensioner assembly is what the heater core hoses attach to on the engine. The lower as it goes into the engine is the one that is fed by the water pump. The other is the return as it goes back into the lower intake manifold.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

I think I might have to put a picture, I am so stupid.

Just go look at your car. The one that is lower as it connects to the engine is the one you want.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

Never mind, I had it backwards. Been a while since I thought about what direction the coolant flows through the heater core. The upper one as it comes out the engine would be the heater core feed. The return line goes down by the pump and is channeled to the inlet so it can continue to be circulated.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

lol Now your making me even more nervous lol

Trust me. The line that goes to the pump is the return line. You can see in this pic the routing of the lines as they go into the tensioner assembly (it's near the center of the pic laying against the strut tower).

http://img.photobucket.com/albums/v3...p/DSC02746.jpg

You want the upper one as it connects to the engine. No matter how they're connected at the heater core, that is the one that feeds it with hot coolant.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

Hmm ok so the top one is the one to splice. I got confused cause the top one on the engine the actual rubber tube is flowing under the one in the bottom. Like for instance imagine a big X. The lower left point is the lower hose and the upper left point of the X is the hose that is connected just above it. The top one flows down ( \ ) and the lower ones flows up ( / ).

Okay here is a picture. Unlike the picture you showed me, my heater tubes flow like this



Top one somehow goes under the bottom one and bottom one goes over the top one. Anyways, slice the one I circled right?

That's the one. The heater core itself isn't directional so it can be hooked up either way. But on the engine that's the one that would be pumping fluid out.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.