Still overheating!

I finally got a new intake manifold put everything back together but it is still overheating. This was after replacing a radiator, thermostat and a water pump. I drove it all the way to work and the temp guage stayed at about 3/4 the whole way but when I got into town to the last stop light it pegged to red. I was sure that the problem was the intake gasket because it was in bad shape when I took the intake off. One thing that I did notice is that when I went to bleed the cooling system I was getting nothing but water from the bleeder above the water pump but seem to get a lot of steam from the one around the thermostat. I am stumped, the only thing I can think of now is the head gaskets and I really don't want to pull this thing apart again! Any ideas? I am getting 3x signal error, low voltage to the water temp sensor and knock sensor codes, all of which are new this go around but that does not explain the overheating.

I finally got a new intake manifold put everything back together but it is still overheating. This was after replacing a radiator, thermostat and a water pump. I drove it all the way to work and the temp guage stayed at about 3/4 the whole way but when I got into town to the last stop light it pegged to red. I was sure that the problem was the intake gasket because it was in bad shape when I took the intake off. One thing that I did notice is that when I went to bleed the cooling system I was getting nothing but water from the bleeder above the water pump but seem to get a lot of steam from the one around the thermostat. I am stumped, the only thing I can think of now is the head gaskets and I really don't want to pull this thing apart again! Any ideas? I am getting 3x signal error, low voltage to the water temp sensor and knock sensor codes, all of which are new this go around but that does not explain the overheating.

Have you flushed the cooling system? Including the heater core? Thoroughly? Put the garden hose in every hole, till it comes out somewhere else?

As far as the steam goes, sounds like you still have an air bubble in the system. The low voltage input to the sensors will give an incorrect reading coming out of them. If the knock sensor is causing the ignition to be too slow due to a low volt input/incorrect reading, the timing may be too slow causing the engine to overheat.
Also be sure that the cooling fans are working properly, as faulty reading from temp sensor could cause the fans not to come on @ the proper time.

Had the same problem. 2 h2o pumps. Reduce antifreeze and add more water.
Solved for me. [email protected]

Drill one or two small holes (1/8") in your thermostat. This will allow the steam to escape past it and open up, solving your overheating problems. This fixed the problem I was having with both my 3.1's - air gets trapped in the system and is almost impossible to get out sometimes.