When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I randomly will not have heat my RDX. I can be driving and then air goes completely cold. I've checked under the dash and the air mix doors are working fine - I can see the levers and rods move and redirect the air through the heater core. From reading in the service manual there is an actual valve the limits coolant to the heater core. Has anyone heard of this failing on the RDX? It seems on other Acura's it might gum up and get stuck?
Also double check that your coolant is not low. In some cases low coolant means it won't reach the heater core, even if you don't have any other symptoms. It could also point to issues with your thermostat, and not necessarily a valve specific to the heater core. Good luck on your search!
Also double check that your coolant is not low. In some cases low coolant means it won't reach the heater core, even if you don't have any other symptoms. It could also point to issues with your thermostat, and not necessarily a valve specific to the heater core. Good luck on your search!
Will check tomorrow morning. My plan was to do it today after work but I got held up, and then the RDX was too warm before sunset.
Originally Posted by CSmoney28
Keep me updated and if I come across anything I'll let you know buddy.
Not the RDX, but I have heard of that valve sticking when the coolant is not changed as suggested. Not changing the coolant will also cause the heater core and radiator to leak.
Update: I found and lubricated the valve and verified it moves....unfortunately still no heat. With the air intake disconnected i verified the valve was moved open to shut when the climate was changed from high to low.
I ran the HVAC system's self test and it showed no problems either. All i got out of this endeavour so far is a check engine light...because i turned the key to (ii) without plugging the air intake maf/mav sensor back in. Either the valve seized back up after i reconnected the intake, or I have a bubble in the heater core, or the heater core is jammed.
Valve is on the firewall below the brake booster.
Going to have it inspected at a dealer shortly. If they diagnose the heater core as bad I’ll have an independent shop flush it. The hose’s location is such a pain to work with
Hello and thanks for posting this diagram, I have a 2011 RDX and need to troubleshoot that part, looks like it's on the firewall I'm guessing, it was replaced in 2017 ,I live in south Florida and use the heat/defogger maybe 2 weeks out of the winter and I noticed its just blowing cool air again,, maybe its just sticking.
thanks for your post
FYI my issue ended up being the cable under the dash somehow disconnected itself. My theory is the valve in the engine bay jammed/gummed up, and the cable came loose when it wouldn't move. After lubricating the heater valve in the engine bay + reconnecting the cable, I am back to having heat.
For what it's worth at this point, the same thing happened to me as well, but in an 07. I removed the blend door thinking that was it, but it functioned fine, and I tried to manually move the cable, but it was seized. I cleaned it all up and lubricated it, and it works fine now.
I just went looking for it to find what it was exactly, but if I recall it was a dielectric grease safe for plastics, and it worked great. Adjusting noise went away. Went a couple more years without a problem, and then it got stuck on cold again, and I left it until the following winter when I needed heat again and discovered it was the cable that was corroded on the firewall side, lubricated that with some WD 40 or Fluid film, and it all works good again. Although, the internal mechanisms of the blend door are making some irritating noises again, but functionally seems to be fine. Not my problem anymore, but I disclosed all that effort to the new owner so they don't think I am ripping them off.
My engine bay looks like it has 1/2 inch of salt on it right now due to the 10 Canadian winters this poor thing has endured. Apart from rust creeping up on the rear fenders it still runs like a champ.
Is there a procedure available anywhere for lubricating the heater valve in the engine bay + reconnecting the cable?
Hi, it's been a while since I owned this car, but I personally didn't do any work on anything heat related near the engine bay, but did take apart the heater blend door mechanism if that is what you are talking about. Sorry, not familiar with anything like this under the hood. The blend door actuator is on the drivers side of the car near the gas pedal. You'll have to take that off and work the actuator out and make sure it still works, isn't stripped and is well lubricated, it will fix the problem, assuming you are talking about having lost heat inside the car and it is making mechanical noises as the gears strip when using the climate controls. Just be careful not to actually move the accelerator once it is disconnected from the electrical connections, it will throw a code when you put it back together. If this isn't what you are talking about, sorry!
10-01-2020, 06:41 PM
