I wish mine would have been fixed by cleaning, but I did that months ago when I had the radiator out to change out the vacuum pump to block gasket. Mine wasn't really that dirty on the outside, and I couldn't really see much inside the radiator.

The new radiator is in and everything seems OK, but I won't be able to really find out if this is the fix until I drive back from work Monday if the temp is over about 92 degrees F.

So far, by driving around town here, the temp goes to slightly below the center of 80 and 100 degrees C, which would be about 88 degrees, the opening temp of the thermostat. It didn't move from that point in the couple of short trips I made.

I'm keep you informed, in case any of you are having the same type of problem. Remember, my problem was a slowly creeping up temp while driving on the highway with the A/C on and the ambient temp above 92 degrees F. At slower speeds, the engine cooled to about 88 degrees C and would stay there. My radiator external was clean, had fresh coolant in, and a new thermostat, and no leaks at the cap, or anywhere else, and the fan clutch passed the turn off test (when hot, the fan stopped immediately when the engine was turned off), and I didn't have pressure in the upper radiator hose after the engine was off about 6 hours (this is the quick and dirty test for a bad head gasket or head cracks).


Joe