Posted: Mar 01 2008 at 1:49pm | IP Logged

Subpud,

While responding to lakota, it just dawned on me.  You probably have a coolant overflow bottle seperate from the radiator.  One that has a cap on it as well, giving you 2 caps!. Are you puting coolant in the overflow bottle or actually in the radiator itself?  Make sure the "radiator" if full, "then" worry about the overflow bottle.  Also, don't use a radiator cap that you can "release" the pressure unless the vehicle came from the factory with it.  They can cause even bigger headaches sometimes.

Hope this helps!

Posted: Mar 05 2008 at 7:24pm | IP Logged

Subpud,

dannyg has a point as far as the head gasket.  I didn't want to go down that road, but since you continue to have problems, it's always a possibility.  Pull your oil cap off and look at the underside of it.  Does it look kind of milky?  Like a shake?  Pull the dipstick out.  Does the oil on it look milky?  If no, then at least you probably aren't getting any coolant in the oil which can put a lot of premature wear on the rings and bearings. Remove the radiator cap and let the truck get up to full operating temperature.  Do you see air bubbles constantly coming up?  Try driving the truck with the radiator cap on only half way and see if it gets hot.  What this does is prevent the cooling system from building up pressure which could force the coolant into a cylinder through a blown head gasket/cracked or warped head etc...  If you can find a reputable shop near you, they should be able to test the cooling system for exhaust gas in it.  It's known as a "block check".

The cooling system is the most important part of your engine and can cost you the most money in the long run so don't cut any corners and take good care of it.  Keep us informed!!