Which is more accurate...dash gauge, or Merc smart Craft?
05-26-2019, 08:44 AM
#1
Registered
Thread Starter
Which is more accurate...dash gauge, or Merc smart Craft?
I believe that I know the answer...but want to hear some feedback.
Inhave a Formula 292 with analog dash gauges and also a Garmin that is connected to the two 320hp merc 377 mag engines. so, in effect, I have most gauges doubled up.
Yesterday, I noticed that the starboard engine was running a little warmer that the port...170 vs 180. Didn’t really worry about it as it far from being hot, just to check, I went to the Garmin and checked water pressure, and it showed both engines equal...then looked at the temps, and they were also very close to equal, and at the lower of the two dash analog gauges. Don’t have a digital readout on the Garmin, as they are a displayed ina Agar format where you can set the gauge min max parameters...but they were within a degree or two.
So, I am going to guess that the ecu looks for engine info for tuning and alarms, and then this information is also then sent to the dash gauge...which is analog Livorsi.
Is is it the right conclusion that the analog gauge is most likely off a little and the Garmin is the more accurate number to use? The boat is a 2014, and has 160 hours on it.
Are my conclusions correct?
Inhave a Formula 292 with analog dash gauges and also a Garmin that is connected to the two 320hp merc 377 mag engines. so, in effect, I have most gauges doubled up.
Yesterday, I noticed that the starboard engine was running a little warmer that the port...170 vs 180. Didn’t really worry about it as it far from being hot, just to check, I went to the Garmin and checked water pressure, and it showed both engines equal...then looked at the temps, and they were also very close to equal, and at the lower of the two dash analog gauges. Don’t have a digital readout on the Garmin, as they are a displayed ina Agar format where you can set the gauge min max parameters...but they were within a degree or two.
So, I am going to guess that the ecu looks for engine info for tuning and alarms, and then this information is also then sent to the dash gauge...which is analog Livorsi.
Is is it the right conclusion that the analog gauge is most likely off a little and the Garmin is the more accurate number to use? The boat is a 2014, and has 160 hours on it.
Are my conclusions correct?
Last edited by Revspan; 05-26-2019 at 08:45 AM. Reason: Spelling error
05-26-2019, 08:51 AM
#2
Platinum Member
Platinum Member
yes you are correct. I'm not sure where the analog gauges get their temperature from, but the ECU reads the engine temperature from the engine coolant sensor. It then passes that info to the digital gauge which reports exactly what the sensor reads. Analog gauges are notorious for being inaccurate.
05-27-2019, 05:18 AM
#4
I'm not sure where the analog gauges get their temperature from.
And the other one on the housing is an analog water temperature sender for the analog type gauges...See it's numbers 3 and 6 for reference between the two, https://www.mercruiserparts.com/bam/...1789/15044/190
Also mercruiser offers an analog gauge interface kit device which allows the conversion of a digital signal to an analog signal, https://www.michiganmotorz.com/mercr...on-p-3508.html , https://www.ebay.com/sch/sis.html?_n...AUGE+INTERFACE
Digital is generally accurate but you can't totally count out what the analog could be trying to tell you too...It could be the analog sensor is seeing something the other side of the thermostat housing isn't quite seeing engine temperature wise or you're stating to see one of the components starting to fail in-turn a higher temperature reading.
It's normal for the analog components to read slightly higher than the digital components for accuracy but the analog components should also be within uniform of each other too since you have two engines...The following link will help explain why the analog components aren't as accurate as you'd expect them to be but again they should be "with-in" uniform of each other when everything else is in an conditional working matter.., https://www.jamestowndistributors.co...t.do?docId=842
I'd say next time out try watching the analog gauges all the way from cold to full temperature to see where they start to separate from each other that way you'll have more of an settling confidence of what might be happening should they ever change state more rapidly all of a sudden.
05-28-2019, 11:27 AM
#6
Gold Member
Gold Member
I assume the data going to your Garmin is going through the Merc NMEA 2K gateway? FWIW, my mechanic told me that is not always 100% accurate. As compared to going straight to smartcraft gauges or vessel view. i guess somethings can be lost in the translation from CAN to NMEA 2K.
Racer
