94 xj 4.0 auto. I've been through 3 of them from advance Auto crap to Crown Auto(right know it sprays out) and each one leaks from the exact same spot...where the steel rocker arm goes into the body. Jeep dealer tells me they don't make them anymore for my umm..."Classic". So where do I go for one that won't leak...or does the bypassing the valve thingy work too?

Do as everyone else does and remove it

I've replaced them before...I understand the concept and if it had been a significant period of time sure but it's only been 4 months...is that a time span I should just shrug and say macht nichts?

You can remove the valve and just run the lines together.

The idea has appeal but it seems to generate as much heat as light.

Except as an affront to the sensibilities of the purists are there any real downsides to doing it...besides coolant running through the heater core continuously?

Does that shorten the life of the core at all by any chance?

MOST modern cars have the coolant flowing all the time through the core without issues and in fact with coolant flowing through it you extend its life because things don't sit and "stew"

Thanks...I don't think a 4th one will be needed.

The heater control valves only real purpose was to justify someones job.

On later ZJs and all WJs, the heater core is full flow anyhow. It's used as a thermostat bypass.

I bypassed the thing on my 95 - works great, no problems and like someone mentioned, having coolant flow through continuously (with it's anti-corrosion additives) is better for the heater core than stagnant coolant. The hose clips along the engine work with the 97+ heater hoses and it looks like it was meant to be that way from the beginning (if you ignore the vacuum hose with the sealed off end zip-tied to some wire harnesses off to the side).

Honestly, I wish there was a reliable heater core bypass.
Summer heat is enough on it's own, I hate having an extra radiator just hanging out behind the dash - inherently heats stuff in the cabin up more.

But it is so much more reliable without one. Just bypass it and call it good

Good point on coolant flowing through the heater core though, didn't think of possible corrosion issues

It must be a FL thing to have the heater bypass heat up the cabin. Up here in the northeast I've never noticed a bit of difference between the heat when I had the HCV vs. when I didn't. The heat and vent seem to work exactly the same.

The bypass or diverters door..... whatever keeps the cool and hot air separated isn't in the best shape in my 01 so I went back and remodified it to my 92 config. I added in a heater control valve. in the summer heat with the core in bypass the non-ac cold air was colder than the cold air with the coolant flowing thru the core by a good 10 degrees or more. of course after a year the stupid valve started leaking again so I had to remove it like everyone else did. obviously its best to fix the seals on the door but I heard that's a pita

Everco 4 Seasons cable operated heater control valve at Autozone, $49.95