86IROC112

So I bought one of those infrared temp guns to check my temp and it appears my gauge is WAY off. I'm told my fan is supposed to come on at 238 and when it comes on the temp gun reads about 220 at the Tstat cover. The gauge reads right up to the red, 250ish.


I know these gauges are famous for being inaccurate so what's the solution? I'd like it to be more accurate incase a problem really does come up someday, I will know it's getting too hot..

midias

Mine is about the same, you can try changing the sender but I just installed an aftermarket gauge in the pillar for oil and temp to get an accurate reading

SbFormula

2015 Autometer Dash Restomod


My dash cluster was becoming so inaccurate after 23 years that I had to do something about it. I went with Autometer custom job. Before all that though, I had added an auxiliary Autometer temp gauge. Now remember, on a 305 TPI, the dash cluster gauge reads from the side of the engine head and the ECM reads near the thermostat on the intake. Even with new gauges there is a difference between the 2. The one on the side of the engine head always reads lower in my case. I also tried ordering a used cluster and it was inaccurate as well.

Best of luck!

Orr89RocZ

iTrader: (20)

Sender in the head could be higher than hose outlet at the stat

I'd try a fresh sender and see what happens. Gauges in my thirdgens seem pretty close to what i read on temp guns on the hoses but keep in mind type of surface those lazer guns hit can change readings so it could also be temp gun inaccuracies

86IROC112

The sender is brand new..What's the best place to get reading with one of those guns?

Orr89RocZ

iTrader: (20)

Flatter darker colored non reflective surface works best. Black rad hose should give decent readings

Scorpner

iTrader: (4)

The cheaper infrared guns probably aren't accurate either. IMO, the best way to measure you engine temp is to buy an after-market gauge, test it in boiling water (which is a standardized measurement) and install it. You could try pointing the gun at boiling water but remember the laser does not indicate a certain test point, instead the infrared sensor is more conically shaped so it may pick up surrounding temp depending on how it's positioned. Boiling water reaches a limit of 212 degrees, while steam does not, so I'm going to assume an immersed gauge sensor is going to be more accurate at reading the actual temp of boiling water.


http://www.grainger.com/content/qt-3...d-thermometers

Nothing in the stock cluster was ever accurate, add to that worn out electronics it will be even worse. Once you establish where actual temps are in relation to the gauge you could theoretically try to tune it in the same way they have done with the tachometers, but it would still have a limited sweep range. (You can think of the stock gauge as a small voltmeter and the sensor as a variable resistor if that helps.) An after-market gauge with a wider sweep range will be more accurate and not as sensitive to minor fluctuations.

If this is a Camaro and you do end up buying an after-market gauge you can temporarily mount a smaller one in the corner in-between the center console and the dash. This would also allow you to return it to stock if you desire.