Please someone help! I have 97 dodge ram with 5.2 and my temp gauge reads about 220-230 guessing. however I have hooked up to computer and temp goes to 210 then T-stat opens and runs around high 190's thereafter. so my questions why does gauge read about 15 degrees off and yes both sensors I replaced. Please help this is super annoying. Also why does computer read different from gauge in dash get temp from same sensor right?? anyway hope a fellow ram owner has encountered this!

 

The actual gauge in the dash could be bad, or a ground wire could be bad.

 

both of the above are entirely possible, but I also wonder about the coolant temp sensor as well. I hear they go out from time to time.....

 

I know where the Tstat is but I don't know where the other sensor is. Could it be one is before the coolant goes into the engine and the other when is comes out before it goes into the radiator to get cooled?

 

According to the pic I have per my parts cross-reference, the coolant temp sensor is close to the upper radiator hose neck on the intake. As stated above, I'd start with your various grounds to make sure they're good. I say this primarily because a bad CTS can cause hard-starting problems (in other words, sometimes they can read too cold when they're going bad, which would cause fuel to practically dump into the cylinders, causing a hard start), which I don't see any mention of, by your first post. Also, if it helps any, in my 99 5.9L I tend to run between 195-205 on the gauge on a normal basis.

 

Thanks for input as I will check grounds asap. The sensors I replaced were from napa and one was directly to right of TSAT and other was to left few inches. Truck would read around 200 or just width of needle over and now it's in between 200 260 but by computer reads normal. Hopefully ground will fix this problem. TSAT is new and Radiator was flushed and was clean too. Everything is normal as far as temperatures go with engine and hoses just this gauge.

 

Gauge gets its reading from the one-wire sensor. If the sensor isn't grounded properly (teflon tape, or something similar on threads) it will give false readings.

 

Did you unhook the battery when you replaced the sensors? I had this exact same problem on mine when I replaced my coolant temp sensor which had corroded away around the connector causing a slight coolant leak. I forgot to unhook the neg. terminal on the battery and then the gauge on my dash read 20-30 degrees high the next day. Went home, reset the computer, problem gone.

 

CSdavies, No I did not, but I'm on it! I'll let you know.

 

coolant temp sensor are made from brass - mine was corroded. Easiest way to get to it is remove the alternator. I replaced mine when I did the alternator.