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Critical VCMUzzler concern

6674 Views 21 Replies 7 Participants Last post by  Drew1987
Per VCMUzzler's own instructions (if i remember correctly), the ECO light may show again if in bumper to bumper traffic for a while, because the car may heat to a little past the "new norm" and reach the "old norm" and allow the VCM system to activate.When I first read that, i wrote it off... it didn't even cause me to think.... but these cars run at 202 or so (forgive me, that's a chevy number but you get the point). If it goes high enough with the VCMuzzler on, its ACTUALLY much more like 210-215 or even more.... that CANNOT me good, and i'm 99.999% certain my needle NEVER fluctuated before VCMuzzler. I would like to hear some feedback for perhaps a Honda certified technician or even an ASE certified tech... I am a good mechanic and fabricator but this is above me.... Seems like its either DESTROY your motor because of software, or let it over heat to avoid it. As I have said before, I cannot even begin to describe the night and day difference - i LOVE the absence of VCM, but now I worry its seeing too much heat. Today my needle was almost where it would be without VCM, but with the smallest resister (blue if I remember correctly - 86om) connected. That's a 10% above normal running temperature variation.Thanks in advance for your conversation
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The VCMuzzler does ABSOLUTELY NOTHING to the actual running temperature of your engine. It only changes what is reported to the PCM and the temp gauge. The engine runs the exact same temperature it always has. Nothing has changed except for the temp being reported.
Today my needle was almost where it would be without VCM,
Sounds like you may have a slight overheating issue, but it's not due to the VCMuzzler.

Thermostat?

Dave
The threshold for VCM activation is 167F so if the ECT detects above 167F you'll get VCM activation. The Muzzler just reduces the indicated temp to the gauges to 167 or below most of the time. When the engine heats up, as occurs in stop and go traffic when the coolant temps climb a bit then VCM may activate because the indicated temp is above 167F. The Muzzler drops the indicated temp about 15-20 degrees, at most, so if VCM activates you're really only about 190F, maybe 195F at the very most. Whatever your vehicle was doing temp-wise before the Muzzler it's still doing after the Muzzler and is not affected by the Muzzler.

When the AC is off, the radiator fans will turn on low speed at about 194F so that's a good way to tell how warm the engine is getting without looking at a scan tool (they use ECT2 so are not affected by the Muzzler) and the fans go to high speed at 205F. If you have high speed fans running WITHOUT the AC, then you know you're at 205F or above. I highly doubt you're getting that hot and if you are, then as Dave mentioned above, it's not due to the Muzzler.
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I'm curious to know how the OP knows the temp is at "210-215 or even more". If accurate, does he have a fan issue he's just noticing?
Thank you all. I was aware of the two different computers and the gauge/vcm being on a different one than the fan. Just surprised it climbs In Traffic. Never did that before. I did do the timing belt and water pump. Thought I burped it perfectly. Maybe it’s tome for a thermostat. But either way, it moves the gauge “down” do if the gauge gets anywhere near the middle, it’s actuakly clearer to 3/5ths. Which as (well) explained above, could be another issue.
That said, maybe I should just replace the tstat. It would devastate me to have damage from heat. I’ve always been one to watch my gauges, now ironically I’ve modified one of them to read low
Also,

I was way off thinking it runs at 202°. 172(ish) is correct, I wonder how much it could run at for extended times? They sell an alternative 180° on rock auto. I imagine 190 all the time would be ok, so maybe I should be concerned


thoughts? I appreciate it
Thank you all. I was aware of the two different computers and the gauge/vcm being on a different one than the fan. Just surprised it climbs In Traffic. Never did that before. I did do the timing belt and water pump. Thought I burped it perfectly. Maybe it’s tome for a thermostat. But either way, it moves the gauge “down” do if the gauge gets anywhere near the middle, it’s actuakly clearer to 3/5ths. Which as (well) explained above, could be another issue.
That said, maybe I should just replace the tstat. It would devastate me to have damage from heat. I’ve always been one to watch my gauges, now ironically I’ve modified one of them to read low
Yes, your car always did this before. You just didn't notice. It's perfectly normal. The temp will fluctuate based on load, amount of air flowing through the radiator (vehicle speed,) thermostat position, radiator fan running or not, etc. Under normal conditions your coolant temp will fluctuate between 185-205F
Also,

I was way off thinking it runs at 202°. 172(ish) is correct, I wonder how much it could run at for extended times? They sell an alternative 180° on rock auto. I imagine 190 all the time would be ok, so maybe I should be concerned


thoughts? I appreciate it
I would stick with OEM thermostat unless you live in a very cold part of the world and need more heat in the winter time. I always replace the thermostat at timing belt/water pump change since the coolant is already drained and it's cheap insurance against a failed thermostat.
I'm curious to know how the OP knows the temp is at "210-215 or even more". If accurate, does he have a fan issue he's just noticing?


I didn’t see this but I answered already - I was dead wrong thinking “norm” is 200° and I added 10-15. What I would hve said if I knew norm is 170° Is “180-185”
John Clark I guess I am used to Toyota Lexus. 200,000 of the 800,000 or so miles I’ve driven we’re in just two cars - 1999 Camry 2.2 and a 2006 solara 3.3 and NEVER saw a needle fluctuate from ambient -20°f to 103°f but my 1950 (which i built) fluctuates a lot but never really creeps. I use a 185°f and it stays 170-190° but that’s a bad comparison as it’s made from dinosaur poop.


Also, yes, i agree I’ll leep it stock. Is the thermostat a pain? And how much coolant do I loose? I have less than a qt on hand but I guess I can buy a gallon.

Burping this car is awful. Honda’s official Method is torture
I'd plan on losing at least a gallon, possibly into a second gallon, if you do a thermostat change.

On the needle position on the gauge I often wonder if the manufacturers program the needle to sit at a normal position when in some predetermined temperature range. I haven't watched it that closely but it's possible that the needle rises to a certain position and stays there until it gets above some threshold like 210 or 215 or something before it starts to rise above it's "normal" position. This is mere speculation on my part and it has little basis in fact other than I rarely see the needles move above their normal range when I know they do fluctuate in temperature. When we install the Muzzler we're increasing resistance and the voltage (somewhere between 0.5v and 4.5v) that the PCM sees on the ECT1 signal wire which causes the indicated temp to be lower on the guage, technically below it's "normal" range.
I could be wrong on this (van is away with the wife and daughter for a girl's weekend), but isn't that temperature sensor on the return flow from the radiator? That is why the VCM temp is so low on the activation - under normal circumstances, the return temperature from the radiator to the engine runs around 180 degrees or so.

You do not want to run a lower temperature thermostat in the engine, as it will cause poorer fuel efficiency and higher cylinder wall wear. SAE testing has shown increased wear at cylinder wall temperatures of 180 degrees F. and below. A lot of car forum guys think they are doing a great thing by going to a 180 degree F. thermostat but most of them are doing it for the wrong reasons. If the capacity of the radiator is too small for the vehicle, you can put a 120 degree thermostat in there and it won't matter, as it will be fully open, just like a 180 or 195 degree thermostat also would be, when the radiator can't reject all of the heat that the engine is putting out.

edit: now I have to add that on cars like most Hondas where the thermostat is on the cold (return) side of the radiator, that a 180 degree thermostat may be what is stock. My discussion above is for typical older American V8s that have the thermostat on the hot side of the system where the coolant exits the engine. So long story short: stick with the thermostat temperature rating that came on the vehicle.
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ECT1 is on the outlet going to the radiator and ECT2 is on the inlet coming from the radiator. You want it this way otherwise if you had a stuck closed thermostat and the engine was overheating you'd have the gauge indicating cold.
I use a seven blade racing fan, because I’m running the stock radiator with no shroud. When it’s cold out, or even in the 70s, and I’m going 60, 65, the car runs around 170. I have plans to go back to a four blade fan, and run a fiberglass shroud that I’m going to build, that should make for better cooling in stop and go traffic, but less dramatic cooling at highway speed. That seven blade fan is about 15 inch diameter, and moves enough air for the car to take Flight if it didn’t have fenders. I worked with what I had :)


as for the Odyssey, I’ll be keeping an eye on it. I am just very concerned to see a 10% spike in stop-and-go traffic, especially was it was 50°f outside and I was (as always) gentle on the throttle
I will add that my “stock” radiator was for a 216 or optional 235 CID six banger. It’s currently cooling a 350 v8. The 7 blade was $4 at a swap meet.
Original. Do they go bad on these?
Original. Do they go bad on these?
There's probably nothing wrong with your radiator cap. At 140K mine was leaking a bit (had a slight coolant smell but no visible leak) but it affected nothing else.
Ok. Thanks.

Thanks for everything all. I will be keeping an eye it
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