Cherokeegirl99

Another view. Heater control valve????

Heater control valve????
Hello fellow Jeepers. I have a question concerning my 1999 Cherokee. I am having heating issues and I'm thinking my heater control valve may need replacing. However, everyone I ask about it tells me my model Jeep doesn't have one. I Googled it and have seen several of them pictured but none exactly like the one that IS on my Jeep. I have replaced the thermostat, heater return hose and tried flushing the heater core but I don't think I had enough air pressure to do that efficiently. Still no heat. What should I do next?? I would like to try flushing it again with more pressure.

If the above picture part is not a heater control valve what is it?? When the heater is turned on this part makes a light pecking noise sometimes it is loud enough to hear other times I have to put my hand on it and feel it

Ralph77

Well this is the heater control valve for an XJ.

https://www.autozone.com/cooling-hea...00000060660997

Be on the passenger side near the firewall in the engine compartment. In plain site.
If you had one which you shouldn't. is a '96 and down XJ thing.
So I am wondering why you think you have one.
Are the hoses going to the heater core hot?
I am wondering if it could be a blend door issue.

cruiser54

Correct, Ralph.

Easy enough to check just using your hands on the heater hoses at the firewall. Both should be quite warm and within a few degrees of each other. Let's check that before proceeding.

Mortgage Payer

This is where pictures are helpful.

Cherokeegirl99

Well I logged in on my phone and took a couple pictures and uploaded them but I'm not seeing them on here. (Logged in on my home computer)

Note: I found them I see them now.

awg

those pics are not the heater valve

lawsoncl

I marked the heater hoses in red on your picture. Go easy on pressure when flushing the heater core. You don't want to split it, and then have to tear the dash apart to replace it. First put you hand on the hoses and see what they feel like. Your problem might also a broken blend door or bad belnd door actuator motor. http://heatertreater.net/jeep-cherokee

Mortgage Payer

Evap Purge Valve
While your Jeep sits in the hot sun, gasoline naturally evaporates from the tank.
It is collected into a small vessel that is filled with activated charcoal.

When the engine is running the Eval Purge Valve cycles allowing the unburned gasoline to flow into the intake manifold and be burned rather than stinking up your garage.

BlueRidgeMark

A 99 does not have a heater control valve, unless some whacko decided to install one from an older XJ.

You don't want one, either.

318SixPack

From the angles you sent it looks like it is hooked to either vacuum lines or vapor lines. Is the thing with the green cap on it plumed into a common line with this thing? Then it is part of your vapor recovery system, per the tag on the green capped fitting.

EZEARL

Originally Posted by Cherokeegirl99 View Post
"If the above picture part is not a heater control valve what is it??"

Evap Purge Valve as Mortgage Payer said:

Mortgage Payer

The green cap is over a test port.

Cherokeegirl99

If it is an EPV then why does it make a ticking noise only when the heater is turned on??
Sometimes it is loud enough to hear other times I have to put my hand on it to feel it.

Mortgage Payer

I believe the computer waits until the engine has warmed up and in closed loop mode to start cycling the EPV.
Maybe you are also waiting for the engine to warm up before you are enabling cabin air to move past the heater core.

I don't know why it cycles louder some times vs others.

My neighbor's XJ was so loud that he thought he had valve noise.
I unplugged the EPV and his "valve noise" went away much to his relief.