Rough idle, with or without AC
 

Anyone notice this? Even during my test drive the salesman turned off the HVAC. I turned it back on, so I could see how the car responded under full load. The idle isnt terrible, but not solidly smooth either. I wonder if the car is shutting down 2-3 cylinders at idle? I cant see the needle bouncing significantly, but it is slightly noticeable. Im still on my first tank, 200 miles, so perhaps they put crappy fuel in?

Same thing here. I have over 6000 miles, and idle is kind of rough even without AC. This is especially annoying in stop and go traffic. But once it starts moving it is very smooth.

Wow I don't find this at all. I can hardly even hear the idle when I am stopped most of the time. I hardly ride with the windows down though.

Might drive another just to see what's normal for this car. Mine is rough with both reg and prem gas

I am beginning to wonder whether those with rough idle problems have vehicles that were not properly prepped by the dealership before delivery. My RDX idles so smooth if I did not hear it I might not know it was running.

Here is the part they might have missed:


3,000 rpm.

Attached is the entire TQI for the 2013 RDX Service Bulletin 12-009 last updated June 26, 2012. If you had high tire pressure of 40 PSI that is another part that was not done and would confirm my suspicion.

Good points. Thanks!! I did have 42 psi so I think you're onto something.

Is this something I can do? My car seems to run fine after idle, so do I need to do the CKP pattern learn?

Im almost certain my dealer cut corners, the shift lock cover was not there either on my car. Im going to be calling my dealer to let them know how much they dropped the ball.

I would print out the service bulletin 12-009 for the 2013 TQI and inform the dealership you have found at least three things that were not done and therefore if anything was done is suspect so they need to perform the entire TQI on your RDX and also kiss you a$$.

I don't see any reason you cannot redo the idle learn procedure yourself but I don't know if something needs to be done first. Maybe remove and replace the #29 fuse? Anyway whether it works or not you wont know unless you try it. Cannot imagine it making anything worse if you follow the instructions. I would think doing the idle learn procedure requires doing the CKP pattern learn but I cannot confirm.

Just made an appointment and let the dealer redo the TQI properly this time.

Dealer says its within spec according to another rdx comparison, real scientific!...so they did nothing, despite being called out on not doing two other tqi items. I wasted a lot of time dealing with this, the idle must just not be refined in the rdx. Would have been nice if they just did the damn procedure after having the car for a day. Just to be clear, my rough idle is more about vibrations felt during idle, not a fluctuating or bouncing tach needle

I have exactly the same vibrations during idle, not a fluctuating RPMs. It is about 600-650 RPM when car starts vibrating and sound resonance makes ears hurt :), but if I press on gas pedal just slightly so RPMs go to around 700-750, and vibrations are gone and it is smooth. I wish idle would be around 700 and not 600 RPMs.

Anyway I tried the Idle Learning procedure and CKP-pattern learning myself (after pulling and reinserting fuse #29), and it did not help at all. The only change was wiped out seats memory and reset average MPG on the display :-).

Btw, CKP-pattern learning is kind of difficult to do - it says to shift to 1, and decelerate from 5,000 to 3,000 RPM, but it never stays in 1 with 5000 RPM, it switches automatically to 2 right away.

Votnet, I did exactly what you did and experienced the same thing. Perhaps we are just more sensitive? Boy was it nuts accelerating to 5k rpm down my street :0. Does your needle move at idle? Mine stays right under 700 and doesn't bounce...I just feel the damn vibrations. Not impressed when my jetta idles rock solid.

Needle is not moving when at idle, it always stays right between 600 and 700 marks, maybe slightly closer to 600. When AC kicks in it might move slightly.

It actually gets a bit better if I shift to neutral, so that what I do sometimes when standing at a long red light.

I remember I test drove 2013 RDX twice back in April before I bought mine, and both were vibrating the same at idle, so I kind of expected this.

Anyone know if the dealer can bump the idle rpm up by 50-100 via programming? That would take care of my problems.

Votnet, sounds like we have the exact same issues...shift to neutral makes it better for me too. Just for kicks, I tried the ilp on a cold engine after keeping the fuses out for 1 hr. same results.

Mine was missing that cover too. I went back and they put one on, but nobody mentioned anything about an idle procedure.

How's is your idle? The idle learn procedure doesn't appear to do much anyways.

Did you have the correct tire pressure?

Sometimes the idle is so smooth I cant even tell the car is on, but sometimes it vibrates slightly (with or without climate control). It's sporadic and I haven't figured it out yet. My 07 RDX used vibrate at idle all the time but that was a straight 4. I think the new RDX cuts off half the engine at idle, down to a straight 3. Maybe that's why it vibrates sometimes.

The tire pressure is fine, around 33-34 psi. My outside temp gauge is crazy though. It's like 30 degrees off.

Speaking of idle concerns, I've noticed the cooler weather really sets our initial idle much higher on a cold start. I'll bet the RDX would cruise at 25mph or better with the cold idle. It is significantly higher than the idle speed when the temps were warmer. We've had a few mornings in the 40s and I'll bet the RDX would 'back' out of the uphill driveway with no added throttle at all!

Just a heads up to those with 'tight quarters' like a carport or tight parking. On a cold start, even after a few seconds to 'wind down', the idle speed of the RDX would send the vehicle on its merry way in a flash.:what:

The car has an active mount control that is supposed to even out vibration from the engine when it runs on 3 or 4 cylinders. Maybe that system is not working well on your car.

Outside temp will go crazy if your speed is really low or when you are stopped. That's because the air is hot from the engine. Drive the car at 30Km/h or more for 5-6 min and see if the temperature indicator improves.

what is the active mount control? a mechanical or electronic device? I suspect the car is on 3 cylinders at idle and it vibrates due to that. On the freeway, when the car is likely on 3 cylinders, the car is VERY SMOOTH. My problem is only at idle.

According to Honda:
"An Active Control Engine Mount system (ACM) is used to minimize the effects of engine vibration as the VCM® system switches cylinders on and off. Sensors alert the Electronic Control Unit (ECU) to direct ACM actuators positioned at the front and rear of the engine to move to cancel engine vibration."

Read about it here, under NOISE, VIBRATION AND HARSHNESS (NVH) CONTROL

http://www.honda.com/newsandviews/ar...spx?id=6556-en

I've read this press release before, and it makes me laugh due to the vibrations this car has at idle. It's enough to warrant me selling the car. Acura says it's "normal." BS

I just did a test drive... idle is rough at light in drive....

400km on the clock and I get slight vibration at lights as well. Nothing dramatic but there.

I have experienced this issue. I bought my 2013 AWD base from McGrath Acura in Westmont, IL. Initially, I was very happy with the vehicle. But, when my car hit 900 miles, (yes, only 900), the car was very loud when idling, especially in park. I brought it into McGrath. They told me it needed a new transmission. They diagnosed the sound was coming from the transmission. Wow. They took care of me with a loaner, etc. I just picked up my vehicle on Monday 5/6. By Wednesday, the loud idle was back. Yes, they replaced the entire transmission. Acura gave me a free bumper to bumper warranty for 7yrs/100k. McGrath gave me a check for the equivalent of 1 car payment. Yes, they took care of me. BUT, now what to do. The noise is back. To describe it, the vehicle drives mostly fine. When you start the car, it sounds fine. However, after driving it for more than 5 minutes, it idles so loudly. Since purchasing the vehicle, I have only put premium gas (93) in it. Again, McGrath was told by Acura to replace the transmission, which initially seemed to be a good fix. But, the sound was back within 48 hours. I have set up an appointment with them on Monday so they can check it again. I am at a point where I don't want them to "fix" it. I want the manufacturer to replace the vehicle. Thoughts?

There is a person that made a similar post to this one and after they got new tranny it occurred again. This is a major manufacture problem from honda they need to step up and back up their product. It all starts with the tranny torque converter. Same issues as the Honda Pilot and Odysee. I had my tranny from my Pilot done twice already one by honda and the other time by me. No prob with Rdx but it flatters me hearing these stories.

That’s a bizarre story. Reading some of the posts here with regard to the rough idle and now your story, it makes me wonder about the 2014 AWD RDX w/Tech package I just picked up a few days ago. However, if it was a “real” transmission problem, it would have shown up in many more cars by now. Nevertheless, after what you’ve been through, they SHOULD buy that car back from you. It should even qualify under a lemon law in many states.

Lets be clear here. My "rough idle" is not severe - more like a 4 cylinder idle Vs a 6 cylinder idle.

For example, my 2007 MX-5 idles much rougher than the RDX.

The rough idle I have is a little dissapointing for a premim brand by not transission swap worthy.

^^^ same here. A little rough, but just a bit distracting not much more.

thats crazy with the tranny replacement. I wouldnt keep that car, demand a buy back. Ill never get another Honda product.

I agree! However, I'm a little skeptical about some of the "rough idle" claims. If you understand how this engine works, you wouldn't be so quick to say it's idle is rough. The transmission issue is another story. If there is anything amusing at all about it, it's the fact that the transmission is the ALL JAPANESE made part.:toocool:

I got the same problem. A slight vibration in drive while stopped. If I put it in neutral it is fine. Just started at 10000 miles. Brought it in and they reprogrammed it but it is atill there...Kind of annoying because everything else is great. If it is not fixed I will sell it and go buy a Lexus.

Bringing this thread back. I've reset the ACM and tested the mounts. I've even replaced The passenger upper mount. The issue isn't there. I have the vcm muzzled, so no 3 & 4 cylinder mode.

I get a lot of vibrations stopped in drive. Very smooth otherwise. This feels almost as if the torque converter is applying a load onto the engine. Did anyone find a fix for this issue?

When the engine was stock, I only ever noticed a rough idle when I filled up the tank with anything other than 93 octane fuel. (With the performance mods I've made, idle is now always a little rough)

First, may I ask what year and how many miles on your RDX.

The VCM may not be causing your issues. I would first clean the throttle body and do the idle relearn along with the Crank pattern relearn. I have used CRC GDI Intake valve cleaner and it really works. Before I started the treatment I looked at the cylinders, intake and exhaust valves. Before treatment Cyl 1 was full of carbon along with valves. After treatment the cylinder was perfectly clean and the valve were shinny clean. If you decide to do treatment, afterwards perform idle re-relearn.

Other things that will cause rough idle is spark plugs, ignition coil, injectors, clogged cat's, intake manifold and valves, leak in vacuum system, leak in intake manifold and low cylinder pressure.

Spark plugs, ignition coil, injectors and clogged cats and be diagnosed by using a lab-scope. Look at your ignition waveform to see if your ignition system and injectors are working good. Use a pressure transducer in each cylinder to verify valve seating and to look for clogged cat's.
If you don't have a lab scope and transducers then you could do is replace components until the issue is resolved.