Scan Guage 2 accuracy

[3ac3]

I recently installed the Scangauge 2 and I'm getting temp reads from 210-215* while driving and up to 225* at idle. Outside temps have been about 70*. Those temps seemed a bit on the high side after doing a search on Dweb. So I took the truck into California rover where they used the infared temp gun for several read outs. The gun never showed a reading higher than 199*. However during the same time the scanguage was reading 220*.

My question is which guage is more accurate? Scangauge or the infared gun? And if it's the scangauge I'm assuming I should be concerned with those temps?

The tech also noted that the fan clutch and the electric fan seemed to be working properly. My truck is an 04 D2.
thanks in advance.

 

[Jake1996D1]

I recently installed the Scangauge 2 and I'm getting temp reads from 210-215* while driving and up to 225* at idle. Outside temps have been about 70*. Those temps seemed a bit on the high side after doing a search on Dweb. So I took the truck into California rover where they used the infared temp gun for several read outs. The gun never showed a reading higher than 199*. However during the same time the scanguage was reading 220*.

My question is which guage is more accurate? Scangauge or the infared gun? And if it's the scangauge I'm assuming I should be concerned with those temps?

The tech also noted that the fan clutch and the electric fan seemed to be working properly. My truck is an 04 D2.
thanks in advance.

My scangauge reads 185-191 and I believe it is perfectly accurate. Only difference is mine is a D1.

Where are you getting your reading infared reading from?

Have your radiator flow tested

 

[3ac3]

My scangauge reads 185-191 and I believe it is perfectly accurate. Only difference is mine is a D1.

Where are you getting your reading infared reading from?

Have your radiator flow tested

The tech was pointing the infared gun at several points in the engine. hoses in and out of radiator, engine itself, and directly at the sensor that I was told sends the signal to the ECM/scanguage.

 

[Jake1996D1]

The tech was pointing the infared gun at several points in the engine. hoses in and out of radiator, engine itself, and directly at the sensor that I was told sends the signal to the ECM/scanguage.

Yea the sensor reads the temp of the coolant. You're not going to get the same reading from the sensor as you are trying to get it thru an insulated hose.

The scangauge is right, your truck is running hot. My guess would be radiator if the fan clutch is working. You can also search on D2 T-stat mod.

 

[3ac3]

Yea the sensor reads the temp of the coolant. You're not going to get the same reading from the sensor as you are trying to get it thru an insulated hose.

The scangauge is right, your truck is running hot. My guess would be radiator if the fan clutch is working. You can also search on D2 T-stat mod.

Thanks. I was hoping the infared gun was right! Damn. I'm surprised the tech didn't seem concerned that the scan guage was reading 220 and his temp gun was under 200.

Do you happen to know what a radiator flow test typically runs?

 

[Jake1996D1]

Thanks. I was hoping the infared gun was right! Damn. I'm surprised the tech didn't seem concerned that the scan guage was reading 220 and his temp gun was under 200.

Do you happen to know what a radiator flow test typically runs?

It's not that his gun was wrong it's that the application was wrong

Shops will do them for free usually if they do the work for you afterwards like a flush, rod or recore. D2 Rads are cheaper you may as well buy a new one if it needs work. call some shops.

 

[p m]

I have both IR gun and Scangauge in my D1. Typically, IR gun reads about 5-15F lower at the radiator intake port than Scangauge.
Keep in mind that the IR readings are only true for "ideal-black-body" surface. Matte black paint of the radiator is close but still not exactly there; aluminum surface of the intake manifold (where the temp sensor is located) is worse.

FWIW - on a 70F day, my D1 Scangauge reads from 185-195F while cruising at ~70mph on flat ground, and it'll shoot to 204-210F at the stoplight after a highway joint. I don't think I've seen SG read more than 224F, and that was hammering up a 4-5% grade at 70mph on a 95F day.
I get about 12-15F of temperature drop across the radiator.

 

[3ac3]

I have both IR gun and Scangauge in my D1. Typically, IR gun reads about 5-15F lower at the radiator intake port than Scangauge.
Keep in mind that the IR readings are only true for "ideal-black-body" surface. Matte black paint of the radiator is close but still not exactly there; aluminum surface of the intake manifold (where the temp sensor is located) is worse.

FWIW - on a 70F day, my D1 Scangauge reads from 185-195F while cruising at ~70mph on flat ground, and it'll shoot to 204-210F at the stoplight after a highway joint. I don't think I've seen SG read more than 224F, and that was hammering up a 4-5% grade at 70mph on a 95F day.
I get about 12-15F of temperature drop across the radiator.

Good to know. Does the D1 run cooler than the D2?

I guess either way its time to start investigating further. What order would you suggest starting with to rule out the culprit that's causing the engine to run a bit hot?
Thanks

 

[p m]

Looks that way. I don't have a D2, just observing others.
You can do the inline thermostat mod (plenty of discussion on that subject) and add an engine oil cooler (if your truck doesn't have it).

 

[Devildog01]

I've heard the D2,especially 4.6 runs hotter than the D1.I did the inline t-stat mod and run a constant 184*.It was 85* here a couple of weeks ago and in traffic with the a/c on I never got above 190*

 

[Jake1996D1]

An after thought - Take the IR gun and point it at the radiator, top, bottom, middle and compare the numbers. The numbers should be similar. If not you know where the issue is.

 

[3ac3]

An after thought - Take the IR gun and point it at the radiator, top, bottom, middle and compare the numbers. The numbers should be similar. If not you know where the issue is.

Not a bad idea. That would identify a flow problem correct?

 

[3ac3]

Looks that way. I don't have a D2, just observing others.
You can do the inline thermostat mod (plenty of discussion on that subject) and add an engine oil cooler (if your truck doesn't have it).

Been reading some of the threads on the t-stat mod. Pretty heated and interesting discussion. I'd rather not do the mod as it seems like the engine if working properly shouldn't overheat.

Do you guys know at what temp the coolant will start boiling out of the reservoir? I was told it was something like 230* but that doesn't seem right if I'm idling and the scanguage is reading 225*. That's would essentially mean I'm very close to boiling.

 

[Jake1996D1]

Not a bad idea. That would identify a flow problem correct?

Yes that would be the goal

Been reading some of the threads on the t-stat mod. Pretty heated and interesting discussion. I'd rather not do the mod as it seems like the engine if working properly shouldn't overheat.

Do you guys know at what temp the coolant will start boiling out of the reservoir? I was told it was something like 230* but that doesn't seem right if I'm idling and the scanguage is reading 225*. That's would essentially mean I'm very close to boiling.

I agree it's like putting a steering damper on to fix death wobble. Dampers and inline t-stat's have their place but shouldnt be use to fix a problem.

If my truck was running over 220* I wouldnt drive it.

 

[DarylJ]

Good to know. Does the D1 run cooler than the D2?

In my experience (I one one of each) very much so. And it should. A D2 thermostat is speced to open fully at 206F. A D1 has a 185 in it.

 

[p m]

Just checked one against another - after a 20-min high-speed highway run followed by one-mile crawl in traffic: Scangauge said 206F, IR gun measured 211-212F at the driver's side radiator port and 195-197F at passenger side of the radiator, about 208F near the location of coolant temperature sensor, and 217F at the intake valley gasket. So I'd say Scangauge (rather, coolant temp sensor & its readout circuit in the ECU) was right on the money.

Guess that Utah dust mixed with engine oil fumes made for a good blackbody representation.

 

[crown14]

Peter is correct, the scangauge is only as accurate as the temperature sensor. And the accuracy of an IR thermometer varies on what surface you are shooting.

D1 and D2 are a lot different. 220* Fahrenheit is 104.4* Celsius. I would not consider that "overheating" for a Bosch engined Land Rover...

 

[sven]

People seem to forget that the boiling point of coolant is way higher than 220..Thats if there are no leaks and its holding pressure.

 

[3ac3]

Just checked one against another - after a 20-min high-speed highway run followed by one-mile crawl in traffic: Scangauge said 206F, IR gun measured 211-212F at the driver's side radiator port and 195-197F at passenger side of the radiator, about 208F near the location of coolant temperature sensor, and 217F at the intake valley gasket. So I'd say Scangauge (rather, coolant temp sensor & its readout circuit in the ECU) was right on the money.

Guess that Utah dust mixed with engine oil fumes made for a good blackbody representation.

Interesting. As with my case the IR gun vs scan gauge at idle were almost 20* different. Very strange... I had another tech point the IR gun at multiple points in the radiator and all the temps were even and normal.

Going to change the t-stat just in case and add some water wetter.

So would the consenus be that D2's run a little hotter? And for my D2 the 210-225* range isn't "bad"?

 

[crown14]

Water wetter is a waste unless you are running straight water (or close to it)