Hi Richard, A hand held temp gauge would be of no use for EGT measurement, if you went up a long grade and pulled over, lifted the bed and then, measured the exhaust manifold temp, it would be WAY down from what it was during the climb. Handheld thermometers are OK for reading engine block and radiator temperature.

The only proper way for EGT measurements is to install a EGT probe in the exhaust manifold before the turbo inlet. If the probe is before the turbo, you should not exceed 1250 degrees!

In my case, I installed the probe immediately after the turbo (3" away from the turbo outlet), wrapped the pipe from the turbo all the way to the muffler and I use 1050 as the maximum EGT temperature. Most turbo guys say a loss of 200-300 degrees thru the turbo is normal. With my wrapped pipe, I should be on the low side of loss so adding 200 to the 1050 I use would equal 1250 maximum as stated before.

One other point, you must use the proper wire and wire connections that you can buy from the EGT gauge supplier. Using any other wire may effect the readings and accuracy. EGT gauges are rather expensive BUT I wouldn't drive a diesel without one. Most importantly if any tuning is done to the turbo or injection pump, a EGT gauge is mandatory!

If EGT probe is installed, care MUST be taken to insure no drilling fragments get in the turbo!!!!