Slant 6 Overheating

Old thread, but I finally resolved the overheating issue.

I gave up and brought it into a local shop, they checked it with an infrared gun and found that it was running at 198 degrees - normal. But when they would shut it down, and this is the same thing I kept experiencing, it would spew. So they tried 3 separate radiator caps and had the same problem with all of them. They thought that the mouth of the radiator was warped and not sealing properly. They sent me on my way, replacing the water pump and alternator belts, and tightening them - said they were loose. So that might've been part of my problem.

I took the radiator out, back to the shop that built it for me, and the guy pressure tested it. 16 psi with my cap. Perfect, though he recommended I go with a 14 psi cap. He said I was probably overfilling it (even though I was only filling it to top of the tubes), told me to put less water in it, install an overflow jug on it and call it done.

So that's what I did - I installed a 32 oz gatorade bottle with a 3/8" hole in the cap for the overflow hose, plus a tiny air hole, wired it to the grill, and no more mess. How about that.

Plus, in all that effort, I also got my dash gauges working again and I can actually see the temperature now. :P

I learned a lot in troubleshooting this problem, but I also learned that a lot of problems have very simple, non-technical solutions. And I'm a very happy driver who now takes his 4 yo to school and makes a 50 mile roundtrip drive to work every day. Only 16-17mpg, but the uniqueness factor is worth it. :)

Thanks for everyone's help on this one. Sorry the solution wasn't more glamorous.