Hi all,

I've read through some of the head gasket threads to see if I could find some RRC trouble shooting routines. There's some good info out there. It looks like one of the head gaskets is allowing combustion pressure into the coolant circuit. We mad a 750 mile round trip up to the NW Challenge in BC over the weekend, and we started blowing coolant past the cap about half way up. I applied a spare 16 pounder and that seemed to help. On the way home, coolant started blowing through the expansion tank every 100 miles or so, so I removed the t-stat and, for good measure looped the heater core circuit in case there was a clog there. Once I hit a gas station that stocked straight anti-freeze I was able to stabilize the system for the remaining 200 miles home, and we never actually got the engine that warm (maybe 200 deg at the most). It seems pretty clear that it's more than a clogged rad, since the pressure was going up without a jump in temp. BTW - There doesn't appear to be any coolant in the oil or oil in the coolant as yet.


So - next steps are that I'll remove the rad and have it cored at my local shop - then I'm wondering about my options. If I'm going to do a head gasket job, I think I'd rather source a used 3.9 and take it apart, replace anything that looks warn (including all gaskets) and then swap it in. Our 3.5L has 183K and the rocker assemblies are pretty hashed. Plus, it is pretty darned gutless. Oil consumption isn't terrible, but it's at the doorstep of fresh linings.

BTW - I didn't note which direction the t-stat pointed when I yanked it out - do these engines follow the rule of "spring toward block" that their firing order cousins (gm small blocks) follow?

Thanks! -.b

 

Spring goes inside block. Any jiggle device or vent hole in flange goes at 12:00 position.