After replacing the hcv, did you run the engine to temp and feel the hoses on each side of the valve? In heat mode, both sides should be hot, cool mode only one side is hot. Also, can you hear the door moving behind the dash when you change from cool to heat & vice-versa? There’s a heat sink/resister under the glove box attached to the heater housing. Mine went out and all I had was cooling and the blower was stuck in defrost. If you go to change it and it has 5 fins on it, the new replacement part won’t work. You need the one in the 2008/09 Pathfinder. Good luck and let us know how it goes.
I did do both and kept the dash off just to make sure the acuator worked properly before reinstalling. And, did have the truck to temp and turned the heat on. But, neither line in or out of the Heater control valve feel hot. Which is where I'm stuck. And, do you have the part number to the part you're referring to? And, do I have to remove the dash again. Also, out doesn't seen to be such in defrost. It functions properly when I cycle through all vents just no heat
How much fluid was in the radiator overflow when hot and cold? It could be a pressure issue in the system which means there’s a leak somewhere or bad caps on radiator or overflow jug letting air get in. Or you didn’t fill it up enough and you have air in the system. Plus the overflow jugs are prone to leak and very difficult to see it. Just to be sure the cvs is working, (even if it’s new) I would get an in-line fitting to bypass the valve. Remove the hoses and use the inline fitting to tie them together. Do you hear clicking in the dash at all?
Nope don't hear any clicking, and I'll double check everything for fluid wise. What's a good way to burp the system to get any air out?
I use a cooling system tester to force the air out through the overflow. Another way is to jack up the front end or use ramps to get the radiator cap as the highest point, remove the cap, start the truck and get it hot, rev the engine at different speeds for about 10 minutes and it should bleed out. If you plan to do the cvs bypass check, you can use a t-fitting with a cap such as the one Preston has in their kit. No need to raise the truck. Remove the hoses from the cvs and connect them with the t-fitting, run the engine to temp with the cap loosened. You’ll have to play with how loose as the air bleeds out. The entire hose should get hot with the engine. If the air is in the heater core, it will take awhile. Rev the engine a few times during the process. Be aware, this can get a bit messy, but it works.
You’re probably ready to tear my head off as I misinformed you on using the t-fitting to bleed the air. If the entire hose is hot when bypassing the heater core, reconnect one side back to the core. Use a short piece of hose the same size, hook it to the other side of the core and use the t-fitting between the short hose and the hose that would attach on the other side of the core. Then run the engine to bleed the core. I’m so sorry for frustrating the hell out of you. Let me know how make out with it.
