Oldsmobile/Buick Repair: Overheating, head gaskets, flow demand

Question
I just had the head gaskets replaced on my 2000 Olds Silhouette. The heads were machined and no cracks were found. The engine is a 3.4L. When I got it back, it ran hot. I was told it was probably air in the block. I bled the motor several times without any good results. I changed the water pump and the cap. Still no help. I took it to a different shop who said my water pump was bad. They changed it out and again I had to take it back for overheating. They said there was air in the block and that they bled it out. It ran fine until I got on the highway where it got hot again. The temperature climbs to the red and then falls to normal temp. After that it begins fluctuating up and down temp wise. This is driving me batty. Any suggestions would be greatly appreciated.
Thanks
Dave

Answer
Hi
The old "air in block syndrome".
My BEST advice would be take it back...Take it back.... become a pain in that shops rump... keep taking it back until it's fixed.
You paid to have your vehicle repaired. You paid GOOD money... You deserve your car to either be fixed.. or your money back.
One of the two.
Have them check proper fan operation.
Have them check thermostat
Have them check the radiator flow
DEMAND it fixed... you deserve it.
I make mistakes.... we all do. But it really sounds like they did not TEST drive the vehicle.. or they would have seen it running hot.
I could tell you numerous things to check.
If thats the route you want please follow post back and I'll help you find your problem.
But I will say.... I would go get my money back if YOU do the work.
Follow post back if needed.
Good Luck
Pawl