Put in a new thermostat, new water pump, and bled the coolant lines. The radiator fan only turns on when the a/c is on, otherwise, when the a/c is off the engines normal cooling fan never turns on, even when it is quite obvious that it should be turning on as it begins to overheat.

Swapped the cooling fan relay for the power window relay and this has not helped. (Power windows work fine still)

If it were to be a bad head gasket, wouldn't I see a leak of some sort, or perhaps coolant in my oil? If so, I do not see any of these symptoms.

Any suggestions?

 

Check/Test the engine coolant temperature sensor. It's located on the thermostat housing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">If it were to be a bad head gasket, wouldn't I see a leak of some sort, or perhaps coolant in my oil? If so, I do not see any of these symptoms.

Any suggestions?</TD></TR></TABLE>

No, not necessarly. If you have a compression tester, you can pressurize the cylinders.

1) Remove the radiator cap.
2) Turn crank until cylinders 1 and 3 are at TDC.
3) Thread in the compression tester to cylinder 1. Hook up and air line on the end of the tester. Check for the coolant in the radiator to bubble out. Repeat with cylinder 3.
4) Do the same thing with cylinders 2 and 4 as you did with 1 and 3.

If no bubbles occur, your head gasket is a-okay.