Is it the waterpump?

[Oldgearz]

Ok so I was tinkering w/my guages since they don't work. I took the cluster apart, cleaned everything up and put back together, now fuel guage works, but coolant temp was still showing C when truck was running. I then troubleshot the problem, cleaned all grounds that I had access to, then went to Pep Boys, got a new sending unit for a 66 (all that was in stock). I hooked it up, ran the truck, now showing right below H when warmed up and running around a little bit. So I figured the thermostat was maybe stuck closed. I removed it put it back together, ran the truck around a bit and it was going right back up to the H. Is it the waterpump? I did notice my coolant looks like crap now that I removed the thermostat. Truck runs fine, the newly rebuilt radiator is hot but barely any hiss at all when I loosen the new radiator cap. Can this be just a bad ground or is my waterpump shot?

[fasteddie1964]

Is the radiator cap new? Could be a bad cap. Water that's not under pressure will get hotter.

[Oldgearz]

Well, I believe the thermostat was part of the problem, based on the nasty looking coolant, and I just found an faq that indicates I got the wrong sending unit, which was for a 66, most had resistors to show accurate temp. I think I will just go for the correct sending unit, then go from there. Let's call this "Silly Sunday"....:S