Ok, here's my dillema. My cluster temp gauge has been acting up the last few weeks so I went ahead and installed a scan gauge to see if the pcm was getting roughly the same reading and they were completely different. I have been ignoring the cluster gauge but lately it has been getting hot so today I let it idle and the fans turn on when they are suppose to.
The thermostat is a 160 and I did have it out of the car earlier this summer and boiled it just for the hell of it and it was fine. Other then that I haven't messed with the cooling system all summer so unless an air bubble just appeared for no reason that shouldn't be an issue.
I have a custom radiator from OFI and 2 spal fans that are less than a year old.
When the car got hot only two radiator hoses were hot too. THe upper hose that goes to the t-stat and the small d.s. 90* fitting that goes to the lower d.s. radiator were hot and the rest were cold.

What do you guys think? I will try and bleed it but I wonder if the water pump has taken a **** hence no circulation and some hoses still cold? It isn't leaking out the weap hole and it isn't squealing.

 

If you don't have any circulation then I would check the water pump. They don't always show signs that you would normally expect. The only other thing is some sort of blockage. I would take out the t stat and see if both hoses warm up and if it circulates. If it does then it is possible that your t stat is bad.

 

Hope this helps... Possibly, the LT1 WP is still in bypass mode. This would require the T_stat not to seal the bypass port inside the WP. The coolant will not circulate to the ouput hose (Left side - it should be hoter than the right side hose) and, return to the rad for cooling. The LT1 (and gen 3) use a "bypass T_stat" type. Also, make sure there is no vapor lock (or blockage) in the cylinder head/ return line. Possibly remove the line, seal with vice grips, and, check flow when @ temp (remember to plug the Rt. top hose connector. The head return line should pass coolant to the top right side of the rad. If not, critical boiling and vapor could insulate and cause reduced heat transfer to the cooling media. I have gone to evans waterless and removed the T_stat, so, I had to design a device to seal the bypass WP port. (97ss M6 383 D1.) B.

 

The haynes manual says an easy way to test the pump is to pinch the top hose off during idle and when you release you should feel a surge meaning the pump is circulating. I did that and couldn't feel anything. THe water pump is stock with 69000 on it.
I'll check to see if the return line is flowing. It was hot though. I will also try and bleed it and see what happens.

 

I just went to bleed it and there was no coolant in the upper hose to bleed and the whole time it ran it just blew steam out the hole. WTF?

 

I have a 95 Z LT1 with 83,000 miles, and I am on the verge of throwing about 5 gallons of gas on it and torching it. There is NO WAY to bleed this F****** cooling system and I don't give a rat's a** who says otherwise. I've searched and there are as many different solutions including tarot readings and Mexican hat dances as there are problems. Just when you think you've got it...8 more friggin minutes of psssssssssssttttt out of the bleeder! I've hooked up surgical tubes, enima bags, empty beer bottles and garden hoses to this piece of s*** and it ain't the friggin head gaskets either. When I bought this car with 50k on the OD, and saw 2 bleeders on the hoses, I knew at that very moment that this was gonna suck, and it did. AIR!
Thats about as close to the truth as anybody is going to tell you.

 

Forget about the stupid bleeder screws. Just fill the system thru the thermostat housing and then the radiator and keep topping off for a few days and make sure to keep overflow bottle at the correct level. No big deal.

 

The coolant is topped off and i'm not loosing any. It either isn't circulating and/or its got a very large air pocket.