ovation

Since we bought our RDX new 3+ years ago it always seemed to be a weak AC system. Over the last 1+ year it went from bad to worse. 3 trips to the dealer, and each time we were told: "All the measurements are with spec.", "It's working as designed.", "It's a common complaint and Honda America won't do anything about it.". And then the ultimate, "It is was it is."

After much investigation and testing on our part we pressed the dealer again, as the 40k warrantee was about to expire. They had the car for a week, replaced two cheap parts on the system, and the AC now runs COLD. Colder than ever, down to 44 degrees at the vent!

Backstory:

We live in south Florida and this is my wife's car. She constanty complained about the terrible AC. I agreed. 3 trips to the dealer and nothing was done. "There is nothing we can do. It is was it is", etc.

But then she told me she has 2 friends with this same 2021 RDX in our neighborhood that told her the AC is great in their vehicles. So on a hot and sunny day I did a side by side test. I put the 2 vehicles outside for any hour in the sun, and with an instant thermometer I tested each and recorded the result.

Temps at the vent (Mine vs theirs):
- 1 minute from starting - 80 vs. 60
- 2 minutes - 70 vs 48
- 4 minutes - 69 vs 48
- 4 minutes inside the car at the driver's position - 86 vs 75 (theirs was comfortable at this point.

Also on hot days after being parked outside, ours would NEVER cool down. After 20 minutes, it was still only 69 at the vent and the temp inside was 80.

Armed with these numbers I went back into the dealer. If my neighbor's RDX got cold, then I know it it not a deisgn problem, or an "It is what it is." result. These RDXs are very capable of producing COLD air, and there must SOMETHING wrong with my car. They gave me a 2024 RDX as a loaner. It had a vent temp of 45 within minutes.

They first found that the refrigerant was low due to a cracked valve at the test ports. They replaced that valve, filled the refrigerant, and said, "It's fixed."

I did another side my side test in their lot vs. my 2024 RDX loaner. The loaner BLEW mine away. "I am keeping the loaner until you fix this. This is her 3rd RDX and she loves these cars. But she is going to sell this car and we will never buy another Acura if you can't fix it, and that is not right." They gave me no problem, and kept working at the car.


In a more detailed system test, which measured high and low side pressures, vent and ambient temps, out temp and even outside humidity found the low side pressure was high. The master tech suspected that the expansion valve was opening too much. He replaced it ($30 part), recharged, and re tested. The low side pressure went from 35 to 30 with the new part. (High side pressure was fine at 55 before and after.) This fixed ths AC.

On our drive home the vent temp got down to 44 degrees.

I appreciate that the dealer spent a week to fix this problem and did not brush us off this time, but wish they fixed it when we first brought it in.

So if you have a 3rd gen RDX, or maybe even a new MDX which I've heard also has AC problems, and have a vent temp that does not get into the low 50s or mid 40s, take it in a have it fixed!

Good luck!

jmhumr

Glad they fixed it. I was always miffed by the complaints about the AC because mine has always been ice cold, so it's nice to see an explanation. You might want to post the invoice so people with lazy service techs know where to point them.

alphaqup

I got a 2024 RDX as a loaner for my MDX being in for warranty work. The AC on it was as you described on the RDX. I hated that 2024 RDX loaner due to how it never cooled down after sitting outside in South Florida as well. Took 1 hour of driving before it became comfortable on two trips. I actually own a 2019 RDX, and I do recall the AC being terrible upon initial purchase. However, it's no longer like that. The 2019 RDX made a weird honk type sound when AC would come on. Luckily the dealership reproduced it and fixed it. It was fixed with the replacement of an expansion valve or solenoid as well. The sound went away, and we've never complained about the AC since the fix. I'm guessing the 2024 RDX loaner had similar issues as you.

retiree

My 2020 runs cool and not cold too. Can you provide the part number of the item they replaced? Thanks

Obolonsky

https://www.acurapartswarehouse.com/...ion_valve.html

Texasrdx21

Had a similar issue a few months ago, actually for years but it appeared to be getting worse. Never was a fan of Acura or Honda AC systems.

Acura evaluated the system, evacuating the current charge, tested for leaks (none) and refilled the system to MFG pound spec. Low and behold, the system was over filled by the factory almost 3 1/2 years ago, now its much colder and vent temp of 43 degrees. Still not Lexus, Infinity or BMW meat locker cold in the vehicle - but noticeably better.

To me the system is not as powerful to cool as other mfg's. Here are things I have done in help the vehicle stay cooler - especially in the Texas summer oven.

1. Change the air-cabin filter every 9 months (cheap and easy DIY)
2. Get ALL the windows ceramic tinted. The rear windows are factory dyed for color, but do little to reject heat or UV rays.
   1. Tinting the windshield LLUMAR Air 80 reduced the cabin temps drastically - cooler dash, vents, steering wheel and seats. 80% looks almost clear, and zero issue driving at night or getting pulled over for being too dark.
   2. My tinting %'s are: 80% windshield, 30% driver + passenger doors and 70% or 50% on the rears windows.
3. Rinse out the AC condenser in front of the radiator monthly (super easy to remove the panel in the engine compartment - and get a low pressure hose in to rinse out the dirt and debris).
4. Pano-Sunroof - Hate that thing, thin electric cover does almost nothing to reduce heat coming through it. I slide a light windshield reflective sunshade in there in the summers - helps reduce the solar gain heat in the summers.

markAZ

Our 2021 A/C works fine, blows cold shortly after backing out of the driveway and cools down the car just fine. We park it in the garage when home, that probably helps altho the temp in our garage can be pretty warm, esp when it's over 100F here, which it's been all week and is supposed to hit 110F for a few days. When parked outside at those temps it still starts blowing cold within a couple minutes but will take a while to cool the interior but not excessively so, IMO. It helps to put it in non-recirc mode and/or open a window for a few minutes to exhaust the really hot air. And, of course, parking in the shade helps a lot...shaded parking spots are always filled first here, even if they're some distance away from the store entrance.

Our 2014 also worked well except for right before the extended warranty ran out when it stopped cooling. Took it in & they found a leaky fill valve. They replaced the valve core (similar to a tire valve), about a $2 part, refilled it and it's been fine since, about four years ago...our daughter still has it.

Anyway, if your A/C isn't working well, it's likely low refrigerant, it isn't a consumable so if it's low there's probably a leak somewhere, or expansion valves are always suspect...it only takes a small piece of crud to clog them up. A good shop should be able to diagnose it fairly easily.

ovation

Great tips. I found the ceramic tint very effective. I did LLumar IRX30 on the front side windows. Really helps reduce that burning sun shining in on the side of your face. I did not touch the rear side windows or hatch. With the IRX30 on the front sides, it gives the white RDX a good look, evening up the tint on the front and rear of the vehicle. I also did the AIR 80 on the windshield, which is a big help. But here's a tip for you: Put LLumar IXR15 ceramic on the 2 pano panels on the RDX. Those REALLY help cool that glass and reduce the heat. I am able to keep the sunshade open for 3 seasons. The interior is beautiful with that dark tint up top in the non-summer months. No problems after 3+ years here in the south Florida sun..

alphaqup

Here's the TSB with the part and instructions that they used on my 2019. It may be purely a coincidence that this part "fixed" the cooling problem. It definitely fixed the weird sound though. It could very well be the servicing and checking of the ac system after the part replacement that fixed it along the way. Regardless, the TSB specifies what they did.

http://www.urvi.net/forumfiles/SB/B19-014.PDF

Texasrdx21

Well done. Couldn't agree more - the side windows and windshield were the HUGE game changers in reducing cabin solar gain! The LLumar Air 80 is optically clear and just adds a slight tint to the windshield - but rejects 99% UV and 42+% heat rejection. Can actually touch the top of the steering wheel and dash in the summers without a 3rd degree burn. Plus, night driving is not affected.

I choose not to ceramic tint the pano-roof, as adding tint does increase the temp of the glass. My simple, cost effective and removable solution reflects the rays out of the glass and also provides added insulation for the summer and freezing winters.

John from PA

Note, the expansion value is not generally a user replaceable part without some specialized refrigeration tools. To remove/replace the valve, the system needs to be evacuated of the current charge, then the valve can be replaced, then the system is evacuated again, then a proper refrigerant charge is put into the system, usually based on weight.