Hey guys, hope someone can help. '98 F150, 4.6, has no heat. Blows cold air and the hoses going in and out are both cold. Just had mechanic check it all over and there are no leaks. Gauge is normal, but still blows cold air. The kicker is this....Sometimes the temp gauge will max out and the oil light will come on and I shut off the truck, coast a bit, restart and everything is normal! Okay, is it Heater Core?, Heater Control Valve?, Water Pump?...I'm loosing my mind! http://images.ibsrv.net/ibsrv/res/sr...ilies/bows.gif

Thanks jk

 

Thermostat? Easy and cheap.

 

More than likely you have a "Head Gasket" problem.