I would recommend both, the thermostat and flushing the radiator. Please keep in mind, what you have described (getting hot sitting in traffic) usually indicates the fan clutch. Here is why. If the vehicle runs at a normal temp when moving, that tells me the t-stat and cooling system are working. However, when sitting, the temp under the hood should lock the fan so it spins at the same speed as the engine. Even though it feels tight, it may still be the problem.
Let me know what you think.
Friday, April 23rd, 2010 AT 6:24 AM