Temperature gauge issues
 

I have a 98 xlt 4.0.

Truck has been out of service for a while and finally recently got it running again. Been driving around town for a few weeks, with no real issues, but after 1 or 2 days of recent highway driving, the temperature guage jumped up to H and stayed there. Even after truck fully cooled down.

Today I replaced the thermostat and temperature SENDING unit, but not the temperature SENSOR for the PCM.

As soon as I got it back together and started it up, the gauge went straight to C. But as I test drove it, the gauge stayed pegged on C the whole time. Even after going on the interstate for a few minutes.

Should I have replaced the SENSOR also?

Thanks in advance.

Re: Temperature gauge issues
 

You able to figure this out. I had a same issue 2 temp sensor from auto zone none worked correctly
So i went on the change out to After market temp gauge , found at LMCTruck.com the pillar mount x3 and gauge for oil pressure, temp and volt meter I going to install soon

Re: Temperature gauge issues
 

I think I figured that I bought the wrong sensor, but I think it was labeled as what I needed, just not an oem part. A Motorcraft replacement should do the trick

Re: Temperature gauge issues
 

Don't use pipe tape or any sealant on the threads. It needs to make good contact to ground properly. Make sure the plug fit snugly as well. Also make sure you have a proper coolant level. Air pockets can cause weird gauge readings.

Re: Temperature gauge issues
 

make sure you do some type of air pocket removal. have truck pointing up to allow for the air to move to highest point