How to block the heater core

[mackzilla]

Hey, how is this accomplished? My shut off valve is cranky and not doing it

[00GTS]

Replace the shut off valve?

[dave6666]

The valve is discontinued although there may be new ones still out there let alone plenty of good used ones. I did look at a valve that CarQuest had that looked identical but the movement action was 90* off. It was $8 vs. $40 for the factory part.

[mackzilla]

My message from my phone cut off for some reason and now I'm too lazy to retype it.

Thanks guys.

[98RedGTS]

Just connect the two hard lines together before the heater core. I don't recall if they are the same diameter, but adapters can be purchased pretty cheap. Just need to remove the stock lines and put one where I made the green mark on the attached.

39216

[ky13]

^Came here to post this suggestion as well if you just want to bypass the core (loop the lines)

[mackzilla]

Thanks guys and thanks Steve for the chat today. I'm going to loop them and see if that doesn't solve my coolant loss.

[MH60M]

Thanks guys and thanks Steve for the chat today. I'm going to loop them and see if that doesn't solve my coolant loss.

If your heater core is causing coolant loss, you'd have wet passenger side carpet!

[mackzilla]

If your heater core is causing coolant loss, you'd have wet passenger side carpet!

There was 1 time I had a pool of coolant behind the front passenger wheel, that was a long time ago and hasn't reoccurred since I shut the valve off.

Anyway, onto my conundrum. My 2000 looks different than the diagram and does not have two hard lines running parallel on the passenger side. I have 1 line that exits from the back of the head and one hard line going from the heater valve to the engine.

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[98RedGTS]

Yes, should just need to connect those. One is the inlet and one is the outlet for the heater core. Just connect those two lines (inlet and outlet) together to bypass the control valve. All you are doing is maintaining the flow without it going through the heater core.

If you have a service manual specific to the 2000 you could check it. It should have the same type of diagram to help you confirm. If the fluid was outside of the car, I'd agree it was most likely the valve or one of the hoses. You should be able to tell though by running the car with the valve open to see where the leak is coming from.

[Martyb]

I just bought that valve a year ago, just cannot remember the dealer I got it from. I searched on the web and it was easy to find.

[Steve-Indy]

mackzilla, some 2000's have the two parallel hard lines (like on 01's and 02's) and some do not...obviously a mid year change in play here.

This makes it interesting when ordering new hoses from vendors.

[Crimson135]

If your heater core is causing coolant loss, you'd have wet passenger side carpet!

MOST modern cars have a sealed HVAC unit with a drain that runs outside of the car. The coolant rarely leaks into the floor anymore.

[dave6666]

You'd smell it like a mofo.

[dave6666]

mackzilla, some 2000's have the two parallel hard lines (like on 01's and 02's) and some do not...obviously a mid year change in play here.

This makes it interesting when ordering new hoses from vendors.

Um. All Gen 2s through that period use the same hard lines 5245458AC 1999+.

[Steve-Indy]

Correct...our 99 has the two lines as do the 2000's that I have PERSONALLY checked...my info that some 2000's have only one hard line as described must have been in error. Sorry for the confusion.