[John Vannie]

Hello!
First of all I bought this car on May 26, 2021. I found out about the ECO problems, did some research, and bought the S-VCM. I installed it correctly.
Carfax showed that there was a recent tire alignment and wheel balance, so I don't believe the problem lies there. Brand new tires btw.

ECO light came off and everything was fine at low speed; no shudders/shakes going up to like 50 mph on city roads.

I get on the Highway and it does fine accelerating to speed limit (70) I'll stay at same speed for a bit, but when I start to slowly accelerate the engine shakes. I'm lightly pressing on pedal to go up 5 to 7mph and along the way to the new cruising speed it will just shake until I stop adding gas. ECO light still doesn't come on. Its as if it went to ECO mode but not showing the light. Weird.
I figured S-VCM will work at all times. Seems to work at the low speed acceleration.
Can't be bad engine mount since it would shake all the time or most of time.
I'm thinking spark plug change might work. Idk when it was last done. If I get same problem after that then I'm at a lost.
Could it be some spark plugs going bad? I don't have check engine light on.

The car drives quiet and smooth until highspeed acceleration whether I kinda floor it or slowly accelerate

Oh and this is a V6 FWD

Edit: As of June 30, 2021 the New CV Axle shaft fixed the problem.

 

[NailGrease]

Hello!
First of all I bought this car on May 26, 2021. I found out about the ECO problems, did some research, and bought the S-VCM. I installed it correctly.
Carfax showed that there was a recent tire alignment and wheel balance, so I don't believe the problem lies there. Brand new tires btw.

ECO light came off and everything was fine at low speed; no shudders/shakes going up to like 50 mph on city roads.

I get on the Highway and it does fine accelerating to speed limit (70) I'll stay at same speed for a bit, but when I start to slowly accelerate the engine shakes. I'm lightly pressing on pedal to go up 5 to 7mph and along the way to the new cruising speed it will just shake until I stop adding gas. ECO light still doesn't come on. Its as if it went to ECO mode but not showing the light. Weird.
I figured S-VCM will work at all times. Seems to work at the low speed acceleration.
Can't be bad engine mount since it would shake all the time or most of time.
I'm thinking spark plug change might work. Idk when it was last done. If I get same problem after that then I'm at a lost.
Could it be some spark plugs going bad? I don't have check engine light on.

The car drives quiet and smooth until highspeed acceleration whether I kinda floor it or slowly accelerate

Oh and this is a V6 FWD

It does sound like it may be down a cylinder. Is the check engine light on? If so, it needs to be scanned for trouble codes. If you don't have a scanner, most auto parts stores will scan for free.
If the green eco light remains off all the time, the VCM is deactivated. Has the ATF been changed? If not, I recommend a 3 x drain and fill using Valvoline MaxLife ATF. This can be purchased at Wal-Mart for around $18 a gallon. Do one D&F and drive until engine and transmission is warmed to operating temperature, do the 2nd. After 100-200 miles + I'd do a 3rd. The transmission will be about 80% fresh fluid.
Other things I do to keep a smooth running Honda V6 engine....,

• VCM disabled ✔
• Air filter New/Clean, installed correctly
• Air intake tube leak free, clamps tight
• Clean the Mass Airflow Sensor (MAF), unplug, remove, Using CRC Electronic Cleaner or MAF Cleaner, spray a few short bursts directly into the visible electrodes to knock the dust off, let dry thoroughly before re-installing.
• Spark plugs New/Clean, NGK Laser Iridiums (OEM) or Ruthenium HX. (These engines are known to misfires on other brands)
• Spark plug tubes oil free, If oil is present, replace valve cover gaskets grommets and spark plug tube seals, (I'd replace the plenum/intake gasket when doing this job)
• Coils tested, oil free, replace any oil soaked boots
• Replace PCV
• Replace EGR valve (last resort, high milage with unexplained rough idle
• Use 0w20 full synthetic oil, no semi blends or extended performance oil
• Use Top Tier 87 octane fuel or use injector cleaner regularly
• If primarily driven in the city, take the vehicle on some long highway speed drives

 

[John Vannie]

It does sound like it may be down a cylinder. Is the check engine light on? If so, it needs to be scanned for trouble codes. If you don't have a scanner, most auto parts stores will scan for free.
If the green eco light remains off all the time, the VCM is deactivated. Has the ATF been changed? If not, I recommend a 3 x drain and fill using Valvoline MaxLife ATF. This can be purchased at Wal-Mart for around $18 a gallon. Do one D&F and drive until engine and transmission is warmed to operating temperature, do the 2nd. After 100-200 miles + I'd do a 3rd. The transmission will be about 80% fresh fluid.
Other things I do to keep a smooth running Honda V6 engine....,

• VCM disabled ✔
• Air filter New/Clean, installed correctly
• Air intake tube leak free, clamps tight
• Clean the Mass Airflow Sensor (MAF), unplug, remove, Using CRC Electronic Cleaner or MAF Cleaner, spray a few short bursts directly into the visible electrodes to knock the dust off, let dry thoroughly before re-installing.
• Spark plugs New/Clean, NGK Laser Iridiums (OEM) or Ruthenium HX. (These engines are known to misfires on other brands)
• Spark plug tubes oil free, If oil is present, replace valve cover gaskets grommets and spark plug tube seals, (I'd replace the plenum/intake gasket when doing this job)
• Coils tested, oil free, replace any oil soaked boots
• Replace PCV
• Replace EGR valve (last resort, high milage with unexplained rough idle
• Use 0w20 full synthetic oil, no semi blends or extended performance oil
• Use Top Tier 87 octane fuel or use injector cleaner regularly
• If primarily driven in the city, take the vehicle on some long highway speed drives

There is no Check Engine light. I used my Ancel AD410 Enhanced OBD II and it shows no faults.

What I've done so far was get a new DVD player since the one I had wasn't reading disc, a 2021 navigation update disc, cabin air filter, and new brakes. Oil is at 70% now.

I'll get spark plugs changed next using what you recommend and see if that helps.
I'll get the MAF cleaned and buy a can of CRC Throttle Body & Air Intake cleaner

After doing some more tests on my highway driving. I find that it only seems to shake when I give small to normal pressure pedal on the highway. When I do give a lot more pressure will accelerate fine without shudder. Its the light to normal touch on pedal that gives the shakes.
I know I said Kinda floor it will give shake still, but that's not true after re-evaluating it . Seems like a certain amount of pressure will get it past the shaking sensation and accelerate fast and normal.

 

[NailGrease]

There is no Check Engine light. I used my Ancel AD410 Enhanced OBD II and it shows no faults.

What I've done so far was get a new DVD player since the one I had wasn't reading disc, a 2021 navigation update disc, cabin air filter, and new brakes. Oil is at 70% now.

I'll get spark plugs changed next using what you recommend and see if that helps.
I'll get the MAF cleaned and buy a can of CRC Throttle Body & Air Intake cleaner

After doing some more tests on my highway driving. I find that it only seems to shake when I give small to normal pressure pedal on the highway. When I do give a lot more pressure will accelerate fine without shudder. Its the light to normal touch on pedal that gives the shakes.
I know I said Kinda floor it will give shake still, but that's not true after re-evaluating it . Seems like a certain amount of pressure will get it past the shaking sensation and accelerate fast and normal.

Very good,
Just to clarify the cleaner for the MAF can only be Electronic Cleaner or MAF Cleaner, specifically. All else will leave an oily film on the sensor, like intake cleaner.

 

[John Vannie]

Very good,
Just to clarify the cleaner for the MAF can only be Electronic Cleaner or MAF Cleaner, specifically. All else will leave an oily film on the sensor, like intake cleaner.

Update!

Cleaned Throttle and MAF with correct cleaners.
Spark plugs changed to NGK Laser Iridium's by a local shop. The old spark plugs were factory ones; may have never been changed. Some of them were ate up; worn down a lot (as shown by mechanic)
After the install, the mechanic test drove it on highway and said the shake is there.
Told me he's not sure what's wrong without having a warning light on to use their scanner to diagnose.

I tested it myself and found that the engine shake at acceleration stayed the same.

When I had my brake pads installed by a different shop 3 weeks ago. I asked if suspension and everything else underneath looks good. They said all looks good, aligned, and balanced.

So yeah...not sure what to check that doesn't show up in a check engine light scenario.
I don't think the Air Intake has a leak. The clamp is on tight. I haven't done transmission flush, but does bad fluid in transmission really cause engine shake in acceleration? I don't feel a gear skipping either and there is smooth shifting. I have limited knowledge on vehicle repair. I do the simple stuff.

 

[NailGrease]

Sounds like it's time for the 3 drain and fills with Full Synthetic Valvoline MaxLife ATF. Wal-Mart sells this for around $18 per gallon (need 3 jugs). I'd do one, drive until the engine and transmission is warmed to operating temperature, then do a 2nd. At this point, you should see improvement in the shifts and any shudder should be gone. Drive a few 100 miles and do a 3rd. Your transmission will have around 80% fresh fluid at this point.
Since you have an AWD, the transfer case and differential fluid would be good to drain and fill using their unique Genuine Honda fluids.

 

[Littleford]

Hey John,
Been through whole scenario….. if u want my uneducated decision it’s your CV- 1/2 axels take it to your local Honda dealership have the truck check to see if u have worped 1/2 axels…. Very common occurrence for these symptoms…. I’m no Honda expert but it would put a couple of bucks on it that that’s your problem… I havnt swapped mine out yet but been told by a couple of educated Honda guys that that’s the source… hope this helps let me know what u find out…. Also do skim on aftermarket unless someone here has a good resource to advise otherwise bc they will warp again…. Go OEM… good luck👍

 

[John Vannie]

Hey John,
Been through whole scenario….. if u want my uneducated decision it’s your CV- 1/2 axels take it to your local Honda dealership have the truck check to see if u have worped 1/2 axels…. Very common occurrence for these symptoms…. I’m no Honda expert but it would put a couple of bucks on it that that’s your problem… I havnt swapped mine out yet but been told by a couple of educated Honda guys that that’s the source… hope this helps let me know what u find out…. Also do skim on aftermarket unless someone here has a good resource to advise otherwise bc they will warp again…. Go OEM… good luck👍

You know what! I just talked to a different mechanic that I'm going to have test run my car tomorrow. I briefed him over the phone and he said it might be the CV axel. So yeah it most likely could be that. I'll keep you updated.

 

[blu3suede]

I have never had that issue with my 2010 crosstour ex-l w/nav now at 126k miles. I do have the S-VCM on mine. There is a way to bypass the S-VCM in the directions that came with it. Have you tried that?

 

[NailGrease]

You know what! I just talked to a different mechanic that I'm going to have test run my car tomorrow. I briefed him over the phone and he said it might be the CV axel. So yeah it most likely could be that. I'll keep you updated.

Just never suspected CV axles to be a problem at 70k miles. One symptom of a bad CV axle is a feeling of repeatedly lurching forward while accelerating in a turn.

 

[FormerSuzukiGuy]

Half axles is where I'd put my money. The other thing to check are the "Motor" Mounts. And don't forget tire pressures, they can make a shudder on acceleration or braking, as if out of balance.
I wish Honda would cover this all too common problem, caused by their poor implementation of VCM. They did change it on the newer models.
Good Luck

 

[John Vannie]

Ok everyone! The mechanic suspects its the front Passenger side CV Axle Shaft. (most of the small noise/rumble is coming from that area) I'm going ahead and getting it replaced next Wednesday. Nothing wrong with engine. Its mounted very well. He is charging $130 for labor.

 

[John Vannie]

Just never suspected CV axles to be a problem at 70k miles. One symptom of a bad CV axle is a feeling of repeatedly lurching forward while accelerating in a turn.

Probably something happened when it was being shipped overseas multiple times. Previous owner was in the military; I can tell from the carfax and some address history left on GPS. It was in Hawaii at first then shipped to South Korea, and then to FT Sill, OK. It did have 1 accident report. Rear-ended and had bumper replaced.

 

[John Vannie]

Update! The CV Axle shaft replacement did the job. No more rumble/vibrations.

 

[Littleford]

Hey John glad u found the problem buddy…. Had a pretty good idea it might be 1/2 CV’s it’s a weakness in the design & can happen at any mileage based off of driving habits…. Riding smooth now bro 👍

 

[Littleford]

John also if u havnt gotten the SVC-M device order it tonight…. It will save your engine plus your mounts which won’t be a nice day on the pocket…. It no more than a $200 fix & gives u true 6cylnders all day …. Hope that helps!!!

 

[NRey76]

Hello!
First of all I bought this car on May 26, 2021. I found out about the ECO problems, did some research, and bought the S-VCM. I installed it correctly.
Carfax showed that there was a recent tire alignment and wheel balance, so I don't believe the problem lies there. Brand new tires btw.

ECO light came off and everything was fine at low speed; no shudders/shakes going up to like 50 mph on city roads.

I get on the Highway and it does fine accelerating to speed limit (70) I'll stay at same speed for a bit, but when I start to slowly accelerate the engine shakes. I'm lightly pressing on pedal to go up 5 to 7mph and along the way to the new cruising speed it will just shake until I stop adding gas. ECO light still doesn't come on. Its as if it went to ECO mode but not showing the light. Weird.
I figured S-VCM will work at all times. Seems to work at the low speed acceleration.
Can't be bad engine mount since it would shake all the time or most of time.
I'm thinking spark plug change might work. Idk when it was last done. If I get same problem after that then I'm at a lost.
Could it be some spark plugs going bad? I don't have check engine light on.

The car drives quiet and smooth until highspeed acceleration whether I kinda floor it or slowly accelerate

Oh and this is a V6 FWD

Edit: As of June 30, 2021 the New CV Axle shaft fixed the problem.

 

[ucdscott]

Update! The CV Axle shaft replacement did the job. No more rumble/vibrations.

What is the Honda part number for the CV axle shaft?

 

[NailGrease]

What is the Honda part number for the CV axle shaft?

Left front (Drivers side)
44306TP6A00
Right front
44305TP6A00
Please verify.

 

[ucdscott]

My mechanic inspected our CT but couldn't find any visible damage to the CV axle shafts. Is the shake asymptomatic or will continuing to drive the car as is cause greater issues?