Your radiator works like a giant pressure cooker, without the pressure, it won't work. The first thing to check is the radiator cap. If the rubber seal is rotton or missing, then it needs to be replaced. If it is the original cap, then I would replace it just to be sure it has the proper tension still in the spring. Next, check the thermostat. It will be right on the engine, either on the lower radiator hose or the upper. You'll see the barb that holds the hose on, and there will be two to three bolts holding the barb on the engine. Take that off and the thermostat is inside. Just replace it with a new one, it will be 6-10 dollars. Next, I would check the coolant temp sensor. It's about 10-20 dollars, using a simple adjustable wrench you can change it in about 5 mins. You'll find it (there could be two) on either/or the inlet/outlet to the upper/lower hose. After that, if it still over heats, check the water pump. You can let the engine warm up, with the radiator cap off, and when the fluid gets to a point of starting to spill out of the radiator, rev the engine up a little. The fluid should rush out of the radiator. If this happens, it's safe to say your water pump works. If it doesn't, it needs to be replaced. Also, be sure to check the belt that drives the water pump, make sure it's not slipping and that it's still there! The last step would be a complete cooling system flush. You can do this by draining the system, (just take off the lower hose and let it drain). Then, remove the thermostat. Stick a garden hose in the upper hose going to the motor and let it run for about 10 mins. Then do the same thing, but hook the hose up to the spot where the upper hose goes to the radiator and flush it clean. After all that, I'm all out of ideas. I hope this helps.
Saturday, June 17th, 2006 AT 8:41 AM