When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So when I get my 2013 Acura RDX approximately 3 years ago, I quickly learned about how horrible the VCM was. Long story short, I installed the S-VCM controller from https://www.svcmcontroller.com/. It seemed to almost completely eliminate the issues I was experiencing.
Over the past few months, I've noticed that my engine temperature gauge will randomly down to zero, and then shortly after there will be a shutter and my engine temperature will slowly return to the appropriate level. Most of the time, this occurs at highway speeds, but not always. Additionally, when I am stopped at a red light, my RPMs will randomly dip for a moment and then return to idling speeds.
In my head, I see two potential issues that could be causing these issues. One being the S-VCM is either malfunctioning and/or is completely dead, so the VCM is getting to do its cyclinder shutdown garbage. Option two is my actual engine temperature sensor is faulty and/or broken.
What are your thoughts? Am I close or have a failed to consider something else entirely. Any help would be appreciated. Thank you.
What are your thoughts? Am I close or have a failed to consider something else entirely.
The engine temp malfunction could also be a faulty intermittent working thermostat that randomly closes and then opens.
But your idle going down and comes up is a different issue. I don't think it is related to engine temp. I would say if the temp sensor was bad you should have gotten a more or less consistent result. Sensors usually experience a sudden death faith.
If I recall correctly, the user manual itself for the VCM mentions that high engine temps/fluctuation can be a side effect of using the VCM. If it seemingly came out of the blue, I would also lean towards it possibly failing.
I quickly learned about how horrible the VCM was. Long story short, I installed the S-VCM controller.
Process of elimination that takes ten seconds. So remove it and see what happens.
Strange, I bought one of those but never used or installed it. And after 7 years of RDX ownership, I've never had a single issue with the VCM system or the RDX.
Process of elimination that takes ten seconds. So remove it and see what happens.
Strange, I bought one of those but never used or installed it. And after 7 years of RDX ownership, I've never had a single issue with the VCM system or the RDX.
Hope this doesn't derail the thread, but wanted to add my experience: 146k miles and 10+ years on our 2014 Tech, no issues with VCM.
Further derailing the thread (but maybe not, because it applies) - I did extensive research on Honda's VCM systems right after we got a 2G RDX. Ultimately, I figured the only "issue" with this generation of VCM was simply the driving feel. Whereas earlier engines with the VCM had legitimate issues with oil fouling on the spark plugs of the disabled bank of cylinders - of which could be resolved by a VCM muzzler. I think Honda had just about ironed out VCM issues around 2013. Any vehicle before that time, with the earlier generation stuff, is where the majority of complaints and legitimate issues appeared to stem from.
Fun photos for reference. Plugs out of our 08 Odyssey J35A7 with VCM, with the rear bank of cylinders (top) in noticeably worse condition, original plugs with 150k on them.
And our 16 RDX's J35Z2, these plugs had 125k miles on them. The wear looks a bit more consistent here.
Further derailing the thread (but maybe not, because it applies) - I did extensive research on Honda's VCM systems right after we got a 2G RDX. Ultimately, I figured the only "issue" with this generation of VCM was simply the driving feel. Whereas earlier engines with the VCM had legitimate issues with oil fouling on the spark plugs of the disabled bank of cylinders - of which could be resolved by a VCM muzzler. I think Honda had just about ironed out VCM issues around 2013. Any vehicle before that time, with the earlier generation stuff, is where the majority of complaints and legitimate issues appeared to stem from.
Fun photos for reference. Plugs out of our 08 Odyssey J35A7 with VCM, with the rear bank of cylinders (top) in noticeably worse condition, original plugs with 150k on them.
And our 16 RDX's J35Z2, these plugs had 125k miles on them. The wear looks a bit more consistent here.
Yup it was prior to the 2013 models where you could spot a lot of VCM issues in the other Honda/Acura products.
Take the muzzler off , and install everything back to OEM. Check all the wiring while doing so. I think that you have a wire somewhere in the mix that is losing continuity .
. About lost all my marbles once when installing a new alternator on one of my rides. New battery and new alt and still no charging. Took the alt off and went back to the store
to have it checked and it was charging perfectly , but not on the car. Sat back for awhile and thought, got up and started inspecting wiring and found a little blacked pin point on the
sheathing on one of the wires going to the alt. I cut the wire there and found the problem and replaced the section and all worked well.
The wire thats used on these muzzlers I think is not heavy enough in gauge diameter , should have been of a heavier gauge.
I will say that the VCMMuzzler I previously installed on the 09 Accord and 07 Pilot made significant difference on the overall fouling of the 2nd bank of plugs.. Prior to that, the plugs were fouled on the back on both cars so it definitely did its job.
Fun photos for reference. Plugs out of our 08 Odyssey J35A7 with VCM, with the rear bank of cylinders (top) in noticeably worse condition, original plugs with 150k on them.
And our 16 RDX's J35Z2, these plugs had 125k miles on them. The wear looks a bit more consistent here.
In both photos, the top two on the right have insulators that are much darker than the other four that are identical. Which cylinders are those and do they relate to VCM cylinders that are shut down?
Not having any driving issues (and I am used to listening to engines when in aircraft), I am unaware as to how the VCM system operates. Is it 2 or 3 cylinders that shut down?
In both photos, the top two on the right have insulators that are much darker than the other four that are identical. Which cylinders are those and do they relate to VCM cylinders that are shut down?
Not having any driving issues (and I am used to listening to engines when in aircraft), I am unaware as to how the VCM system operates. Is it 2 or 3 cylinders that shut down?
So interestingly, I just found out that the odyssey (first photo) is actually equipped with the second generation of VCM beginning with that model year, 2008. I was under the false assumption that it was a first gen VCM car, of which it would simply deactivate the entire rear bank of cylinders (#1, #2, #3). As it turns out, the second generation of VCM allowed the engine to go from full operation of 6 cylinders, down to 4, then down to 3, as the ECU saw fit. I would imagine that cylinder #1 is doing more work, more often, keeping the combustion chamber a bit cleaner than #2 and #3.
On the Honda VCM wiki page, it lists most VCM types and cylinder deactivation patterns for most vehicles - conveniently minus the 2G RDX. It looks 2013 was the launch for VCM-3, which apparently reverted back to the original concept of 3 cylinder/rear bank deactivation. I would bank (no pun intended) on the RDX having this style of VCM.
So interestingly, I just found out that the odyssey (first photo) is actually equipped with the second generation of VCM beginning with that model year, 2008. I was under the false assumption that it was a first gen VCM car, of which it would simply deactivate the entire rear bank of cylinders (#1, #2, #3). As it turns out, the second generation of VCM allowed the engine to go from full operation of 6 cylinders, down to 4, then down to 3, as the ECU saw fit. I would imagine that cylinder #1 is doing more work, more often, keeping the combustion chamber a bit cleaner than #2 and #3.
On the Honda VCM wiki page, it lists most VCM types and cylinder deactivation patterns for most vehicles - conveniently minus the 2G RDX. It looks 2013 was the launch for VCM-3, which apparently reverted back to the original concept of 3 cylinder/rear bank deactivation. I would bank (no pun intended) on the RDX having this style of VCM.
So when I get my 2013 Acura RDX approximately 3 years ago, I quickly learned about how horrible the VCM was. Long story short, I installed the S-VCM controller from https://www.svcmcontroller.com/. It seemed to almost completely eliminate the issues I was experiencing.
Over the past few months, I've noticed that my engine temperature gauge will randomly down to zero, and then shortly after there will be a shutter and my engine temperature will slowly return to the appropriate level. Most of the time, this occurs at highway speeds, but not always. Additionally, when I am stopped at a red light, my RPMs will randomly dip for a moment and then return to idling speeds.
In my head, I see two potential issues that could be causing these issues. One being the S-VCM is either malfunctioning and/or is completely dead, so the VCM is getting to do its cyclinder shutdown garbage. Option two is my actual engine temperature sensor is faulty and/or broken.
What are your thoughts? Am I close or have a failed to consider something else entirely. Any help would be appreciated. Thank you.
As a data point, I recently had Temp Sensor 1 go out in our 2011 Honda Civic we keep as extra car. The symptoms with that faulty sensor was the temp gauge went all the way to "full hot" and I was getting a reading off that sensor of over 300 degrees. Replaced the sensor and back to normal operation. I'm not saying a bad sensor will behave that same way in an RDX, but that's how it behaved in our 2011 Civic.
I'm assuming you have a scan tool for acquiring actual engine temp #'s, correct? If so, it's easy to determine if the S-VCM controller is working or not. With a working S-VCM, your engine temp will sit at 165.2 degrees once up to temp, under normal conditions. If the S-VCM controller is not working, it will register normal engine temp which is usually a couple ticks under 190 degrees. If your S-VCM controller has gone bad, contact the vendor and he'll send out another for the cost of the shipping.
I found out my S-VCM controller had died by a noticeable oil consumption in my wife's 13 RDX. Once replaced, oil consumption dropped back to virtually zero.
03-10-2024, 05:29 AM
