LadyNaRover.... There are lots of threads in this forum that talk about the ticking sound that the engines can make. In my instance, the noise develops only when the engine is hotter than I would like... over 207 degrees. I have found that so long as the temp stays below that... I don't have the noise. I installed a new 180 degree thermostat, flushed the radiator, put a bottle of Luca's Super Coolant in and my truck has been running lots cooler than before and that sound has mostly disappeared. Don't simply trust the factory temp gauge. I use an OBDII tool that gives me exact sensor data (including temp) to my android phone. The cost was negligible.