[HondaBus]

I wanted to post about my experience with both the original VCM Muzzler & S-VCM on my 2013 Pilot EX-L in Ottawa, Canada.

I installed the original VCM Muzzler with the 82ohm fixed resistor in 2014 when the vehicle was almost new and was very happy with the product and the results. It used to throw the odd CEL in the spring and fall but would usually not return after a reset. In 2021 it was throwing CEL's every 2 weeks or so consistently. I changed the resistor in the unit to the 68ohm which resulted in CEL, TRAC, and VTM lights.

After a little research, I installed the S-VCM as it was available right away and actively managed the system resistance. I have not had a single CEL since installation (after 18 months so far). The vehicle has about 145,000Kms and zero engine issues.

 

[cintocrunch]

I never got any CELs with 4 years of VCMuzzler, but I made the switch to S-VCM as well because I liked that the temperature gauge goes to "actual" as soon as the temperature goes above "normal" and well before an overheat situation.

 

[PLT383]

You may be comparing old and new. I’ve been using the VCMTuner II Advanced for well over a year now and no CEL, VCM is 100% disabled and actual coolant temp returns to displaying on the ScanGauge when actual coolant temp approaches 200F. The VCMTuner II disabler disables itself.

 

[dr bob]

I've had a VCMuzzler installed since the car was about a year old. I get the occasional ECO light after sitting in a hot-soak traffic situation, but it goes off almost immediately once the car is moving or the fans come up to speed to shed the excess heat. No CEL's.

The temp gauge is more an idiot gauge than an accurate indicator of coolant temp, even without the VCMuzzler installed. The actual temp range between about 180º and maybe 220ºF causes minimum gauge needle movement regardless. The VCMuzzler moves that gauge-movement range slightly. But since it has no scale, all that changes is the needle position. At the high end of the scale, the resistor adds about 10ºF to the less-responsive-needle window.

Were I starting from scratch, I'd probably choose one of the "smarter" units. At this point though I'm unlikely to change out what I have installed already. I, like a large majority of drivers, only look at the temp gauge once in a while, or when the cluster lights up and gives a high-temp alarm. That ten degree error at one (of the three...) engine coolant temp sensors is unlikely to make a difference in how I respond the gauge reading, although it will delay the temp alarms by maybe ten degrees. Critically, it does not change the fans operating temperature; that duty goes to the incoming coolant temp sensor, rather than the outlet temp sensor when the VCM defeat devices connect.

 

[bdozer1965]

I've had a VCMuzzler installed since the car was about a year old. I get the occasional ECO light after sitting in a hot-soak traffic situation, but it goes off almost immediately once the car is moving or the fans come up to speed to shed the excess heat. No CEL's.

The temp gauge is more an idiot gauge than an accurate indicator of coolant temp, even without the VCMuzzler installed. The actual temp range between about 180º and maybe 220ºF causes minimum gauge needle movement regardless. The VCMuzzler moves that gauge-movement range slightly. But since it has no scale, all that changes is the needle position. At the high end of the scale, the resistor adds about 10ºF to the less-responsive-needle window.

Were I starting from scratch, I'd probably choose one of the "smarter" units. At this point though I'm unlikely to change out what I have installed already. I, like a large majority of drivers, only look at the temp gauge once in a while, or when the cluster lights up and gives a high-temp alarm. That ten degree error at one (of the three...) engine coolant temp sensors is unlikely to make a difference in how I respond the gauge reading, although it will delay the temp alarms by maybe ten degrees. Critically, it does not change the fans operating temperature; that duty goes to the incoming coolant temp sensor, rather than the outlet temp sensor when the VCM defeat devices connect.

I'm using one too, around 35k miles with it and no trouble. A couple times in stop and go on really hot days the system seemed to want to engage but stopped immediately as soon as I started rolling,

 

[dr bob]

I'm using one too, around 35k miles with it and no trouble. A couple times in stop and go on really hot days the system seemed to want to engage but stopped immediately as soon as I started rolling,

I'm of the feeling that it's probably Good Idea to let the VCM system components like sensors, solenoids and actuators, get a little exercise once in a while. The amount of time that the ECO light is on in those hot-soak driving condition is a tiny tiny fraction of a percent of total engine run time. It's certainly no risk to combustion or piston rings even in high-miles engines. In my amateur opinion anyway.

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FWIW, the actual scope of operation of the VCM system is pretty impressive when you think about it. Honda engineers did a pretty good job picking up the ugly byproducts of the missing cylinder-firing, and without counter-rotating "balance shafts" or other complexities. Setting drivability issues aside, like odd transmission shifting and surging, we generally don't see serious problems until there are some oil control issues that happen as the oil scraper rings wear in the bores. Owners can delay those effects with frequent synthetic oil services from birth, so that the rings see less wear and any oil ash and coke deposits in them get washed out quickly. For me, the drivability and odd shifting under VCM were the symptoms I wanted to eliminate; the engine oil in ours gets changed at about the 50%-remaining-life indication on the Maintenance Minder. Plus it's had synthetic oil in it since it arrived home the first time from Honda. Ring and bore wear are not a concern for me.

I'll likely get some bore-scope pictures when I change the spark plugs in maybe eight years or so at the rate we aren't piling miles on the car. I expect see fresh hone marks/hatching on the cylinder walls at that time, consistent with the results seen in previous engines that received the same service protocol. I expect to still see the break-in coating on crank bearings too should I get into it that deep.

 

[MtMan]

For 4 years I was using the VCM Muzzler II on my 2017 Pilot and 2017 Ridgeline. Used the 100 ohm resistor, had no CELs on either vehicle. Picked up a ScanGauge II to monitor the VCM on/off and temperature. Found on both vehicles the VCM stayed off about 90% of the time. So decided to upgrade to the more advanced defeat device, the VCM Tuner 2. Now VCM is disabled 100% of the time on both for over a year now.

VCMTUNER II - Advanced - 2007+ for Honda Acura 3.5L I-VTEC Disable VCM / ECO mode

Backordered. See below. Read Reviews | Vehicle Fitment List Update: 6/20/2022 - Ordering is re-enabled VCMTUNER II. We have sold out our weekly production on this batch as of 6/20/2022. These orders will be shipped the week of 6/21/2022 through 6/24/2022. More product will be available...

www.vcmtuner.com