Resurrected Dauntless overheating

I'm going through my '66 and fired it up today hoping that it was ready to run. But I think I have an over heating problem and need help trying to figure next steps.

The jeep (30k original miles) has been stored 20 years so I rebuilt the fuel system, pulled the plugs, oiled the cylinders and hand turned the engine a bit to be sure it was all lubed.
I changed all hoses and the thermostat and removed the radiator. The radiator was checked for flow and cleaned by a good shop. They also checked the cap.
The old antifreeze looked really good and there was no corrosion anywhere that I could see. Fresh 50/50 was poured in. The waterpump spins ok and doesnt have any play.
By shorting the temperature sender I could see the guage was working but I dont know how good the sender might be.

So I fired it up.

It took a while for the temp guage to lift off Cold.
Then it started puking some antifreeze out the overflow. No problem since I had filled it.
But after some time the temp guage was still very low and I could hear popping and feel popping with my hand on the upper hose.
Shut down - I could hear bubbling in the upper hose - boiling?
I put some heavy tarp and rags over the cap and twisted it off slowly to relieve pressure then put my trusty kitchen thermometer into the coolant and it was reading 190.
Fired it up again and after a while I am hearing that boiling sound again.
Then the temp guage suddenly pegged to HOT.
All stop - I called it quits and rolled it back into the garage. Working outside in the snow is no fun.

I figure:
I better connect a real temp guage.
Check for blown head gasket (compression test?)
Check the new thermostat
what am I missing? could there be an air pocket in there?

 

Sounds like you had an air lock in there. Temp gauge showing cold (after warm up) then suddenly jumping to hot is when the air lock opened up and allowed water to flow around temp sender. Temp sender will not work with hot air or steam. Has to be emersed in hot water. That has been my findings anyway. Mine did the same thing and I jacked up the front end tilting the front of motor upwards and it belched out a lot of air and took more water and was fine after that. HTH

 

When you changed the thermostat,did you put back with air hole it up? most themostat have a little hole or air valve that need to to the top

 

Take the thermostat out and try again, it sounds like it is overheating and you have no water flow ( theromostat installed backwards). Without the thermostat when you first start it you can take off the radiator cap and see how much water flow you have. As it starts to warm up reinstall the radiator cap and let it come up to temp.

 

Thanks everyone
The T'stat did not have a hole but I remember a thread where someone did drill a small air vent. I see where this is going with the air lock and how that would mess with the temp sender.

I'll try to get out there this week, pull the T'stat, try to burp the system and give it another shot. Then replace the T'stat.

Will let you know....
Tom

 

Good luck, sounds like a bad tstat, or as others said... AIR.