A friend of mine has a 2006 Pilot, EX-L 3.5L V6 with a heat problem.

A few weeks ago, it was chilly in the morning, and his wife turned on the heat, but it didn't warm up in the cabin.

Last weekend, I tried to help him troubleshoot. I verified that the "mix" motor turned when the dial was turned to heat, then found the actuator that pushes/pulls the cable was working. Then, I verified that the cable moving the valve on the firewall in the engine compartment was moving (opening & closing), and finally, the "arm" on the valve was rotating.

It appears that all of the mechanical parts to the system are working correctly, but there's still no heat.

Is it time for a new heater core?

Anything else I should look for before we go that route?

 

Problem with front AND rear heat? Do you have a thermometer to get front/rear w/and without ac on?

 

Eh, I'm not sure on the rear heat - I didn't know it had rear heat actually.

I do know that when we were testing, we had the engine running for 5-10 minutes in the afternoon sun, and when I turned the heat all the way up, the air coming out of the dash vents didn't change temp.

 

Sounds like a problem. heh. If the rear heat works, look down the front center vents and see if the blend door moves. You'll need a flashlight. Are the coolant hoses warm? Aftermarket recycled coolant ? I've seen recycled coolant plug heater cores. Feel the hoses to the heater core for warmth. I've never seen a heater core go bad on its own in a honda. Something else is up. Need more info.

 

Got some new info on this. My friend says the rear heat works fine.

I will tell him to try the "look down the center vents" thing and report back.

Thanks for your help!

 

The idea is to make sure the door is actually moving. The rear heat hss no heater valve. Its always hot coolant flowing. The rear uses air mix only. So there could be a heater valve problem internally even though the arm moves. Also, I'd imagine both heater cores would plug if there were an issue with them not just one.

 

Yes, you are right but also please check, whether the fuse of the heater coil is ok, since there will be individual arrangement for mechanical parts and heater coils. so, after that you can go for the new core.

 

No core necessary.

The valve on the firewall broke inside, and was stuck closed.

Ended up costing $30 for the part and an hour labor at the stealership.

Thanks though.

 

What is a heater coil?

By the way, glad to hear the vehicle is fixed.

 

Hi - I'm having the same problem with my 2006 - I went through the same diagnostics you did - I found the valve on the firewall OUTSIDE - is there one INSIDE as well? Not to be silly, but just trying to verify which one you had fixed - I would tackle the one outside the firewall, but probably not inside as I can even see it. thanks!

PS - do you have a part number from your bill on that valve by chance?

Bob

 

As far as I know, there's only the one valve on the outside (engine side) of the firewall.

Don't know what the part number was. It's a friend's vehicle and he took care of it after the initial troubleshooting we did.

 

OK - now I understand your previous post - the valve broke on the inside of the valve, but the valve is outside the cabin, on the engine side of the firewall - that's what was confusion me - I thought you meant the valve was inside the cabin on the firewall

It's weird that something inside that valve is sticking - the arm turns, the screw moves with the arm...but ok - that sure makes sense - i'll check with the local Honda shop - that valve looks reasonable to replace.

thanks for the response - that was just what I needed to know.

 

Had the same problem, no heat in front, but worked in rear just fine. Dealer wanted $3,000 to replace both cores. I chose to try replacing the control valve myself and it now works perfectly for about $12 and a few hours of work.

 

Did you notify the Service Manager and General Manager at said dealer, of "your" find and repair?

You should.