has any one encounter this issue with their temp gauge. my car is warmed up normal temp but it does not show i will have to smack the dash and then it will get a reading for a while and then it will just go back down to the C.
why throw parts at it when you can diagnose it with a multi meter?
Go get a multimeter, set it to ohms. Test circuit. The tmp sender is nothing more than a temperature sensitive variable resistor. You can even pull it out of the block and then test it's resistance after inserting it in a pot of boiling water.
Likely you can find the Ohm specs for different temperatures in the FSM.
So, I'm going to show some of my Accord newbness here, is the gauge driven from the sender directly and the PCM from another coolant sensor, or is the gauge fed a signal from the PCM?
Anyway, since you smack the dash and it comes back to the proper temperature reading I would hazard a guess that it's a loose connection in the back of the cluster. I can tell you that the 97+ cherokees are plagued with this issue and it's a simple fix. Pull the cluster, clean up the connectors and then slightly adjust the contacts to, well, have more contact.