SG II Accuracy?
Freshman User
Joined: Feb 2011
Posts: 49
Likes: 0
If you listen carefully on lift off, the injectors may go quiet which from what I understand is a fuel cutoff, which is when the SG should show the 9999. Basically saying you're getting an infinite mpg due to still rolling and no fuel use. When the injectors start up again the 9999 should change back to realistic numbers. Forgot to check the value, will do later today, sorry!
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
Probably a general distrust of their accuracy. We use those things around here on hot melt equipment, and have proven that they often give wrong results. Differences in color or cleanliness of the material affect them. Also trying to shoot a temp when the target is not large enough is a problem. Most of them have a target dot of around 2" at the distance you would be from an engine. Even though the laser is just a dot.
They are sometimes okay, but in this case if it didn't match what an OEM sensor was showing within 5 or 10 degrees, I would have zero confidence. You guys may have had better luck than we have.
They are sometimes okay, but in this case if it didn't match what an OEM sensor was showing within 5 or 10 degrees, I would have zero confidence. You guys may have had better luck than we have.
Hotshot
Joined: Dec 2003
Posts: 15,368
Likes: 121
From: Stuttgart, Ar
Probably a general distrust of their accuracy. We use those things around here on hot melt equipment, and have proven that they often give wrong results. Differences in color or cleanliness of the material affect them. Also trying to shoot a temp when the target is not large enough is a problem. Most of them have a target dot of around 2" at the distance you would be from an engine. Even though the laser is just a dot.
They are sometimes okay, but in this case if it didn't match what an OEM sensor was showing within 5 or 10 degrees, I would have zero confidence. You guys may have had better luck than we have.
They are sometimes okay, but in this case if it didn't match what an OEM sensor was showing within 5 or 10 degrees, I would have zero confidence. You guys may have had better luck than we have.
Junior User
Joined: Mar 2007
Posts: 62
Likes: 0
From: Zanesville,OH
1. first 5 miles in town really didn't pay much attention .
2. 15 miles interstate 65 mph EOT 204*, fWT 188* constent, ECT 194*-196* this was the mth + 6.
3. 15 miles back with mth normal code. EOT 204*, fWT 188*-190* a few times mainly stayed at 188*. ECT 194*-196* mainly stayed at 196*.
4. 5 miles in town EOT 201* ,fwt 190*-191*, ECT 192*-193*. also mth normal code.
Freshman User
Joined: Feb 2011
Posts: 49
Likes: 0
Thanks for the numbers! Looks like the fWT might be off then IMHO, as it says you never got to 190 which is supposed to be the operating temp of the engine from what I've seen posted. So, knowing your truck better than anyone else, does the ECT or the +6 Mth seem right?
I'm no expert on the 6.0 and still hoping for a definitive answer from somebody about the +6 but seems to make some sense.
I'm no expert on the 6.0 and still hoping for a definitive answer from somebody about the +6 but seems to make some sense.
Lead Driver
Joined: Sep 2007
Posts: 8,180
Likes: 669
From: Scio, OR
The PCM reads the voltage return from the ECT sensor and calculates a coolant temperature. It provides this as a PID. Actually, it might provide multiple PIDs, it might provide ECT sensor voltage, temperature in C, temperature in F, etc. I'd have to hook up AE to see specifically what. AE reads the PCM and determines all the available PIDs for you.
Then the SG reads the PID from the PCM. So, why is the SG reading the PID and getting different values? It shouldn't be possible. The only explanation is maybe it's reading ECT probe voltage and trying to do it's own math, and doing it wrong. Or it's reading C and trying to calculate F and doing that wrong. Who knows.
The thing is, it's all coming from the same PCM, so the numbers should be the same. The PCM provides a coolant temp value, already calculated. Any device should read that value and present it to the user and they should all be the same. When they are not, there is obviously a problem.
If the device itself cannot provide the same reading of one value twice, it's either programmed wrong, or the end user programmed something wrong. Either way, I don't see how the device can be trusted as a diagnostic tool.
Then the SG reads the PID from the PCM. So, why is the SG reading the PID and getting different values? It shouldn't be possible. The only explanation is maybe it's reading ECT probe voltage and trying to do it's own math, and doing it wrong. Or it's reading C and trying to calculate F and doing that wrong. Who knows.
The thing is, it's all coming from the same PCM, so the numbers should be the same. The PCM provides a coolant temp value, already calculated. Any device should read that value and present it to the user and they should all be the same. When they are not, there is obviously a problem.
If the device itself cannot provide the same reading of one value twice, it's either programmed wrong, or the end user programmed something wrong. Either way, I don't see how the device can be trusted as a diagnostic tool.
Junior User
Joined: Mar 2007
Posts: 62
Likes: 0
From: Zanesville,OH
Thanks for the numbers! Looks like the fWT might be off then IMHO, as it says you never got to 190 which is supposed to be the operating temp of the engine from what I've seen posted. So, knowing your truck better than anyone else, does the ECT or the +6 Mth seem right?
I'm no expert on the 6.0 and still hoping for a definitive answer from somebody about the +6 but seems to make some sense.
I'm no expert on the 6.0 and still hoping for a definitive answer from somebody about the +6 but seems to make some sense.
Freshman User
Joined: Feb 2011
Posts: 49
Likes: 0
The two prior posts sum up my dilemma. I bought the SG as a diagnostic tool specifically for the temp deltas. I think it's reading a core value from the PID, that's why there's the MTH section in the xgauge, to convert the core value to a value a human can understand.
I actually got similar values today after pushing the truck in town ECT 204 max, ECT 196 max in 52 ambient temps, no more than a delta of 8, average was about 4. On a cool down idle temps stabilized at EOT 190, ECT 190. That's with the +6 ECT.
So I'm really thinking the +6 might be right, and I'm also in the same boat if it's not, needing a cooler soon.
Plus over the summer without the +6 I showed over a 15 degree delta more than once but never got the CEL on the dash like my latest flash is supposed to set if my delta is out of spec.
I think we really need to find a way to know for sure how to know which MTH is right, but no idea how to go about it. And I don't know anybody with an AE or other tool, don't want to pay my local dealer a diagnostic charge just to find out either!
I actually got similar values today after pushing the truck in town ECT 204 max, ECT 196 max in 52 ambient temps, no more than a delta of 8, average was about 4. On a cool down idle temps stabilized at EOT 190, ECT 190. That's with the +6 ECT.
So I'm really thinking the +6 might be right, and I'm also in the same boat if it's not, needing a cooler soon.
Plus over the summer without the +6 I showed over a 15 degree delta more than once but never got the CEL on the dash like my latest flash is supposed to set if my delta is out of spec.
I think we really need to find a way to know for sure how to know which MTH is right, but no idea how to go about it. And I don't know anybody with an AE or other tool, don't want to pay my local dealer a diagnostic charge just to find out either!
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Junior User
Joined: Mar 2007
Posts: 62
Likes: 0
From: Zanesville,OH
The two prior posts sum up my dilemma. I bought the SG as a diagnostic tool specifically for the temp deltas. I think it's reading a core value from the PID, that's why there's the MTH section in the xgauge, to convert the core value to a value a human can understand.
I actually got similar values today after pushing the truck in town ECT 204 max, ECT 196 max in 52 ambient temps, no more than a delta of 8, average was about 4. On a cool down idle temps stabilized at EOT 190, ECT 190. That's with the +6 ECT.
So I'm really thinking the +6 might be right, and I'm also in the same boat if it's not, needing a cooler soon.
Plus over the summer without the +6 I showed over a 15 degree delta more than once but never got the CEL on the dash like my latest flash is supposed to set if my delta is out of spec.
I think we really need to find a way to know for sure how to know which MTH is right, but no idea how to go about it. And I don't know anybody with an AE or other tool, don't want to pay my local dealer a diagnostic charge just to find out either!
I actually got similar values today after pushing the truck in town ECT 204 max, ECT 196 max in 52 ambient temps, no more than a delta of 8, average was about 4. On a cool down idle temps stabilized at EOT 190, ECT 190. That's with the +6 ECT.
So I'm really thinking the +6 might be right, and I'm also in the same boat if it's not, needing a cooler soon.
Plus over the summer without the +6 I showed over a 15 degree delta more than once but never got the CEL on the dash like my latest flash is supposed to set if my delta is out of spec.
I think we really need to find a way to know for sure how to know which MTH is right, but no idea how to go about it. And I don't know anybody with an AE or other tool, don't want to pay my local dealer a diagnostic charge just to find out either!
I'm hitting easy street
Joined: Nov 2009
Posts: 6,395
Likes: 27
From: Central Oregon
Follow me on this,
So, during the day, when your all your temps are going up outside your fluids follow, then as the temps start going down the same will happen. So Last night you get in the truck, the temps are coming down and the ECT 34 EOT 38, High for the day was what, around 45? Oil will cool slower than coolant. So, at some point in the mornings, both will be about the same I would bet. That would be during the hour when the temp outside starts to warm back up.
So when you check tomorrow night, you will get the same thing, ECT will be lower than the EOT. By how much? not sure, your temp change on wednesday night is less than tonight, 24th as compared to 25th. Your high for the day is supposed to be 38 ,25th, and low to 30, so I'd say around 4 pm your temps should be about the closest you will see.
I'm just throwing out a theory here.
Oil takes longer to cool, and longer to heat.
So, during the day, when your all your temps are going up outside your fluids follow, then as the temps start going down the same will happen. So Last night you get in the truck, the temps are coming down and the ECT 34 EOT 38, High for the day was what, around 45? Oil will cool slower than coolant. So, at some point in the mornings, both will be about the same I would bet. That would be during the hour when the temp outside starts to warm back up.
So when you check tomorrow night, you will get the same thing, ECT will be lower than the EOT. By how much? not sure, your temp change on wednesday night is less than tonight, 24th as compared to 25th. Your high for the day is supposed to be 38 ,25th, and low to 30, so I'd say around 4 pm your temps should be about the closest you will see.
I'm just throwing out a theory here.
Oil takes longer to cool, and longer to heat.
Hotshot
Joined: Dec 2003
Posts: 15,368
Likes: 121
From: Stuttgart, Ar
The PCM reads the voltage return from the ECT sensor and calculates a coolant temperature. It provides this as a PID. Actually, it might provide multiple PIDs, it might provide ECT sensor voltage, temperature in C, temperature in F, etc. I'd have to hook up AE to see specifically what. AE reads the PCM and determines all the available PIDs for you.
Then the SG reads the PID from the PCM. So, why is the SG reading the PID and getting different values? It shouldn't be possible. The only explanation is maybe it's reading ECT probe voltage and trying to do it's own math, and doing it wrong. Or it's reading C and trying to calculate F and doing that wrong. Who knows.
The thing is, it's all coming from the same PCM, so the numbers should be the same. The PCM provides a coolant temp value, already calculated. Any device should read that value and present it to the user and they should all be the same. When they are not, there is obviously a problem.
If the device itself cannot provide the same reading of one value twice, it's either programmed wrong, or the end user programmed something wrong. Either way, I don't see how the device can be trusted as a diagnostic tool.
Then the SG reads the PID from the PCM. So, why is the SG reading the PID and getting different values? It shouldn't be possible. The only explanation is maybe it's reading ECT probe voltage and trying to do it's own math, and doing it wrong. Or it's reading C and trying to calculate F and doing that wrong. Who knows.
The thing is, it's all coming from the same PCM, so the numbers should be the same. The PCM provides a coolant temp value, already calculated. Any device should read that value and present it to the user and they should all be the same. When they are not, there is obviously a problem.
If the device itself cannot provide the same reading of one value twice, it's either programmed wrong, or the end user programmed something wrong. Either way, I don't see how the device can be trusted as a diagnostic tool.
I'm hitting easy street
Joined: Nov 2009
Posts: 6,395
Likes: 27
From: Central Oregon
Ok will try to make sense of this if possible. Drove about 40 miles.
1. first 5 miles in town really didn't pay much attention .
2. 15 miles interstate 65 mph EOT 204*, fWT 188* constent, ECT 194*-196* this was the mth + 6.
3. 15 miles back with mth normal code. EOT 204*, fWT 188*-190* a few times mainly stayed at 188*. ECT 194*-196* mainly stayed at 196*.
4. 5 miles in town EOT 201* ,fwt 190*-191*, ECT 192*-193*. also mth normal code.
1. first 5 miles in town really didn't pay much attention .
2. 15 miles interstate 65 mph EOT 204*, fWT 188* constent, ECT 194*-196* this was the mth + 6.
3. 15 miles back with mth normal code. EOT 204*, fWT 188*-190* a few times mainly stayed at 188*. ECT 194*-196* mainly stayed at 196*.
4. 5 miles in town EOT 201* ,fwt 190*-191*, ECT 192*-193*. also mth normal code.
I can get ECT to get to 194 but not very often. Also, the fan is running to help keep the ECT In check. At 192 this morning, fan speed was around 565 rpms. When I was coasting the temp dropped to 188 and the fan dropped to around 450, then at idle dropped to near 300.
Hotshot
Joined: Jul 2005
Posts: 13,834
Likes: 25
From: Middle Tn.
One more time from the beginning. After an all night cold soak the numbers should be the same. That is where it will tell you if the math is correct. Once the engine is running the temps will, and should, chase each other depending on conditions. Let's not turn this into rocket science math.
