Wierd Problem

[capitlj]

Ok guys so I had a miss problem
http://forums.tccoa.com/showthread.php?t=107396
Thought I had it licked, then today on my way home from work some wierd things happened. First the car was missing like before, at least it feels like a miss acceleration is choppy and at idle it sure seems like one cylinder isnt doing its part. So I drive on pissed off and then a few blocks later it starts running fine. So i do a quick sweep of my guages and my temp gauge is pegged out, well over 240. Its 3 degrees below zero and the car had been running for 3 minutes tops no way it got that hot that fast so I figure I have a bubble in my coolant no biggie my buddy said he bled the coolant after we got my water pump leak fixed well maybe he didnt, whatever. So I get home and take off the rad cap no pressure release or hot coolant. The radiator is full but the coolant is not hot at all. BTW I know its a bad idea to take the cap off a hot coolant system. Maybe my t-stat is messed up but I replaced it when I did the head swap, so I'm not ready to pull the trigger on that one

 

[BlownFiveLiter]

Sounds like a possible bad water pump. The temp gauge might be pegging due to lack of flow, but the radiator would be cold. Your coolant isn't frozen, is it?

 

[blackvertgt]

I have had this happen before too. Turned out to be improper mixture of anti-freeze/water.
While it seems improbable, what actually happens is you get one or more hoses frozen through, but the radiator being thicker and containing more water doesn't freeze. So, the water can't flow through the frozen hoses and can't transfer heat to the radiator. You wind up with the engine block overheating in just a mile or two and a cold radiator, just like your situation. If you shut the car off for a few minutes, the ice in the hoses will melt and all will flow as normal.
I'd drain that radiator and get the right mix in there before you wind up with a cracked block or ?

 

[jrichker]

If all of the above check out good, look for a bad or missing engine to body ground.
The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges. If it is nonfunctional, the temp gauge will read high. A clue is that as you add electrical loads like lights and A/C fan, the temp will increase. Turn off the electrical loads and the temp will drop with the decrease of electrical load.

 

[capitlj]

The grounds were all secured when I did the head swap a month or two ago. I only have 250 miles on the new heads. The coolant thing is unlikely as well since I mixed it myself 50/50. I had to go to work before we could top off the system tho so my best friend took care of that.