I have asked this before without ant results so I will ask agin. I have a 2004.5 chev. with the lly diesel engine and I would like to install another auxliary coolant temperature guage. I need to now where to install the second coolant temp. sensor to get an accurate reading. I don't think it would be a good idea to piggy back it where the OEM sesor is because that might effect the accuracy of the OEM unit. However if that sensor only effects the OEM dash guage:) and not the engine control module it might be ok to hook it up at that location by installing a tee in that location to hook up both units. What do you techs think?

I do not think it would be a problem to tee in the sensor at the same point that the OEM sensor is located. The only problem I could foresee is if you used some long fittings and off set the sensors a large distance from the coolant stream. The heat transfer from a liquid to a solid (your sensor) is huge compared to the transfer to air so if your sensor is offset a little you will not see any difference.