George Knighton

I noticed during my long commute to the country last night that a strange vibration was coming and going.

It was almost like tires out of balance except that I could feel it in the seat of the car *and* and the steering wheel, leading me to believe it was something else.

A little research indicates that the J35Y4 has three VCM configurations: 6, 4, and 3 cylinders.

I'm sort of suspecting that I was in 4 cylinder mode and it was too much for the fancy motor mounts to absorb completely.

Anybody else notice anything like this?

I was using ACC + LSF and the car would vary from 40 mph to 55 mph, with two full stops over 65 minutes.

victorber

Hey George,
What is your current mileage? Was there anything else that was going on during this event? Were you traveling at a higher speed prior to this problem? Did you gas up prior to this event? maybe Unimproved road conditions created this? Did these anomalies disappear when you increased your speed?
I would hope that the power mgmt. system would monitor the speed and RPM to provide a smoother power delivery, but who knows.


I would contact the dealer if the problem surfaces again, they may need to flash your ECM...Just a thought.

Colin

The RLX (and new MDX) VCM switches between 6 and 3 cylinders. The RDX uses the older 6-4-3 system. As you noted, the engine mounts are supposed to dampen out the changeover. I'm not sure on this, but I wonder if switching to sport mode would 'force' the motor into 6 cylinder mode? If so, it might be a way to A/B the vibration feel?

George Knighton

1150 miles now.

Nope, nothing special. Just like 40 to 55 mph using ACC.

Nope. About half a tank.

That's what I thought was the strangest thing. It seemed to be going on constantly, but coming and going, and not mattering much what speed.

I suppose it's possible that sometimes at a certain speed you'd be in 3 cylinder mode, and other times at the same speed in 6 cylinder mode.

I saw a reference somewhere to 6-4-3, but it was a reviewer and we all know that they're notorious for not really knowing whereof they speak.

I think you're right, that Sport Mode might tend to keep the car in 6 cylinders. I don't know whether you've noticed, but it's pretty hard to get into 6th gear below 70 mph, so between that and 6 cylinders, I'd be wasting tons of fuel.

This evening, I haven't noticed it as much.

I have no idea. Maybe I'm just lucky enough to be one of those people who is always going to be able to notice the VCM.

The car was enjoyable this evening, though. "Performance" means different things in different situations, I guess.

George Knighton

Well. On the way home tonight I took the same road as last night, and the vibration was there again.

If it's normal I guess I can get used to it, but the TL never acted like this. The TL was a 6-6, however, so it had no VCM.

Same frequency vibration at various speeds.

Sport Mode = no difference.

Now, here's the thing. 55 mph and slipped it into neutral and off the gas...vibration still there.

Maybe it's some kind of strange thing like it took 1,000 miles for several tires to wear out of balance or something.

Rocket_man

Didn't you just have your PAW-S bolt kit installed??? I'd assume they did an alignment (4-wheel alignment?) on the car after that.

Several years ago I once had a tire that had a belt break or separate inside the tire. I had the alignment checked, no issues. Didn't throw a weight, wheel wasn't bent. Drove me nuts for months and months until I got new tires, issue was gone. It manifested itself as a vibration in the front end in a certain speed band. I think this is pretty rare, and doesn't sound like your issue.

Could always be an engine mount gone bad.... infant failure. Maybe you can put it in sport mode and vary the RPM and see if it is related to engine speed vice road speed.

George Knighton

Yes, I sure did. It has been on my mind some, wondering if the vibration has something to do with that. Since I'm feeling it in the steering wheel as well as in the seat, however, I think it's more likely to be something else.

That's a part of the procedure with the recall, yes.

That has also been on my mind!!

Tried that...no difference. But I haven't been able to find a specific reference anywhere that says that VCM is deactivated with Sport Mode.

Thank you very much for taking the time to think about this.

Perhaps I will have to end up facing the fact that this will not be as smooth a car as the TL was.

weather

George Knighton...You should never accept the fact that the RLX is not as smooth as the TL. You have paid the premium to get Acura's flagship and you should never settle or accept that the car has a "vibration" in in. Cars are never designed to vibrate or run in a non smooth fashion. I could see if the vibration you were getting was just an instantaneous subtle vibration as the engine runs from the 3 to 6 cylinder, I mean that is virtually impossible to make that totally seemless....my RDX has that issue but it is sooooo subtle that I wouldn't blink an eye about it.

In your case, the fact that you feel the vibration in the wheel and in the seat, and this is also experienced with the foot off the accelerator (and car in neutral) tells me that there is something more to this. I am far from being a mechanic but I would have this examined by the dealer. There are so many things that could be causing this but "being normal" ain't one of this.

I had a GM product back in the 90's and that things had a similar issue and turns out that the only thing that solved it was putting new tires (as Rocket_man said)...they had tried force balance and everything.

Now I have to ask you....how long does the vibration last? Is it continuous? Does it do on other roads or just the one you have tried a few times? When did this problem begin?

Could it be:

1. Bent rim?
2. Faulty tire?
3. Failing engine mount as suggested by R_M
4. Bent axle?
5. Wheel out of balance?
6. Poor/contaminated fuel?

The list are endless but I would suggest you take it to the dealer and have them try and solve your issue....No one should be paying that much money for a vehicle and not put a smile on their face every time they drive it.

TLtrigirl

iTrader: (1)

could it be the roadway? same section of road on your commute?? you mentioned it comes and goes.

i know of a couple of roads (freeway) lanes that aren't exactly paved smooth. they have subtle undulations which make the car feel like a wheel is out of balance and can be felt in the same manner you are feeling (with and without the foot on the gas). any other roadway (short of potholes, and there are many here with all the friggin' construction) is fine.

the other thought...could be a suspension bushing? one wouldn't think since your car is so young in mileage. you never know. 3G TLs were known for torn LCA bushings (i suspect that i where my subtle off and on vibration comes from on hwy runs).

holografique

george...

1. this is not something for you to accept. my RLX doesn't behave in this manner at all, unless I'm on bad road conditions. And I've yet to see anywhere else here on the forum complain of similar issues. The steering and handling is laser smooth on mine and I'm already at 11k+ miles on mine. Still as smooth as when I drove it off the lot.

2. I'm with TLtrigirl, you said you took the same road and the same issue happened again. Unless I'm missing something, isn't that the issue? the road? Are you having the problem on different roads? I have to imagine there are lots of places/roads you can drive your car, unless you're way out in the boonies and there's only one road to and from civilization

George Knighton

Haaa ha ha ha ha.... :-)

Okay. Maybe. But the TL did fine on the same road(s).

I'll drive differently today.

George Knighton

Okay, well....

Maybe it was that road after all. :-)

But I protest again that the TL handled that road without shaking and jittering like that.

I think the RLX suspension is just...strange. Very expensive and complicated, that's for sure. It looks like it is made more to handle bouncing over gaters more than it's made for commuting home at slower speeds on a road that's under construction.

holografique

lol! I have to agree with you George, coming from my 3rd Gen TL 6MT, I didn't recall my TL being as sensitive to road conditions as the RLX is. The suspension is very weird. It's laser smooth and responsive unlike anything near what my TL was, which I love and is 95% of the conditions I'm driving in. But when it comes to bumpy roads or other anomalies, the RLX does not handle well and definitely more sensitive than my TL was.

dturboman

I've gotten something similar to this, in 6th gear cruising on the highway I can almost feel it go from 3 to 6 cyl and vice versa, sometimes it lingers on the edge of the 3cy limit and starts to get a little rough, I can feel it in the wheel and pedal, but then it must kick over to 6cyl and its perfect. - I've noticed this before on the Ram MDS too.

George Knighton

My travels take me by the dealership where I bought the car, about three times/week.

I stopped and spoke with somebody the other day because I just happened to notice him outside.

Apparently there's a lucky few of us who are always going to be able to know when the J35Y4 is on 3 cylinders, fancy motor mounts notwithstanding. If you've got a history of owning J Motors without VCM, then your experience might be worst.

My car before the RLX was a 4G TL 6-6 SH-AWD. J37 with no VCM. My car before the TL was a 2006 Accord 6-6 HFP Coupe. Again, no VCM.

So when you combine that with my insistence on trying to drive a secondary road for an hour, a basically unimproved road driven at high speed in the country by all manner of vehicles including tractors, I was just worried.

I notice the car's a lot smooth if I go home on the Interstate...but, hell, that's no fun. And I still notice when I'm in 3 cylinders.

No idea how much truth there is to this, but they say if I notice when the J Motor's on 3 cylinders, there's a lot of competitor vehicles that'd just drive me crazy.

:-)

brantacura

Hi guys seems there is an issue with rubber mounts in low temperatures .Acura have recenlty released a service bulletin involving the the propshaft

SorrySid

maybe a bearing? bad wheel bearings can cause vibration on the floor & in gas pedal. gotta get mine replaced.

George Knighton

No, it was the VCM. :-)

I'm just unlucky enough to be one of those people who can notice it.

R. White

I have noticed, over the past couple of months, a new vibration coming and going in the 65 to 75 mph range. I thought that it might be a wheel problem, but now since everything has been re-balanced and aligned after wrecking two tires, it is still there.

I wonder if the magic motor mounts are wearing out ?

skj

Oh how I wish I would have found this thread and others related to the VCM vibration issue prior to purchasing my 2014 RLX! Right after I purchased it (only 4 months ago) I noticed intermittent vibration around 65+mpg. I immediately took it in for service (again 4 months ago) and they said the tires needed to be balanced...no change. Took it back and the said the balance was still slightly off... no change. Took it back and they said it was a wheel issue, so they replaced the wheel....no change. Took it back and they said it needed "a good set of Michelin tires" however the Acura rep was coming in and would look at it again. After his review, he agreed that it needed "a good set of Michelin tires." Acura paid for 2 of the tires and after going back and forth with the dealer (considering I just purchased the car - certified), they paid for the other 2 and put them on the car. The vibration lessened but did not go away. I took the car back in for oil change and they rotated the tires....vibration still there. I took it to another Acura dealership and they did a forced balance...no change. I called Acura directly to get some help (or shall I say no help!) I took it back again and this time mentioned the VCM based on my research. The Service Mgr stated he'd never heard that the VCM would cause vibration. This was on Friday and on the following Monday, he called to say it was the VCM and the vibration in NORMAL and NO fix! The Acura Rep finally called me back and pretty much said that if the tech is saying it's normal, then there is nothing that can be done! I can not believe that vibration is considered normal. And if it was normal, why wasn't it "normal" when I first brought it in, 4 months ago...before new a new wheel, multiple balancing, tire rotations and new tires. Evidently, even the Acura Specialist must not have thought it was normal since he authorized the purchase of tires. Now, the trade in value has plummeted and I'm basically stuck with a vehicle that vibrates. Had I known the first time I took it in that the vibration was "normal" I would have traded then before the value dropped so much. Extremely frustrated and sooo disappointed. I would not recommend anyone purchasing an Acura or any vehicle with VCM.

George Knighton

Some cars in some modes have a minor spark knock. It's not a bad thing, necessarily, like it would be in the old days.

On just a few cylinders, they lean it out enough for cars a spark knock, and that's just the way it is.

Some of us are not sensitive to it, or can accept it.

But it drives some people crazy, especially older people for whom a spark knock was an indicator of a very bad tune and dangerous engine behavior.

Hard to believe a spark knock is not dangerous in 2018 when in 1955 it'd have made you drive straight to the shop to fix.

George Knighton

But we also get much, much better fuel economy than we did back then.