Jedon

Sat: Start new engine up and let idle
Sun: Go for a drive, after about 3 miles temps rise to 100C and then I shut down to get gas. When I start it back up it's at 113C. I go home.
Monday: Burp cooling system, put more NPG+ in. Temps rise again, up to 122C this time. I figure the thermostat is dead
Tues: Put in new thermostat. Temps seem good, 88C - 98C I figure it's fixed. ( NAPA 180 degree thernmostat )
Wed: Drive in is fine, but when I drive home temps shoot off the scale to 133C at which point the PowerFC no longer displays the temp, gauge voltage shows 0.05V . I **** myself. When I get home and pop the hood there is steam coming from a hose that is supposed to be conencted to the AST->Filler Neck. The nipple on the AST is MELTED! I have another AST so I replace it and remember that perhaps NPG+ likes to run at low pressure so I rip the guts out of a spare pressure cap and put it on the AST. I start it up and it crawls up to 100C at which time I panick and shut it off, I leave the key in to monitor temps and it goes to about 120C before cooling off again. Throughout all of this the engine has seemed fine, purring right along.
pics here: http://www.nopro.com/~jedon/engine/ast.html
Engine: 90% brand new parts, mild street port, ribbed water channels, 9.5lb M2 flywheel, ACT clutch. Other than that, stock
So what could be wrong?
1. Waterpump is bad
2. Blockage
3. ?
Thanx!

Jonesboro

Hi Jed,

If I was in your position I would focus on looking at the simpliest issues:

1. Clogged radiator?

2. Radiator fans not coming on? If so, could be the fans or the thermoswitch.

3. Water pump siezed?

4. Try an experiment. Replace the NPG+ with antifreeze and distilled water mixture and a pressurized radiator cap.

In any case, don't drive any more until the problem is identified and solved.

Jedon

1. I have another radiator off a 55K mile car I could swap in.
2. Fans are working fine, low and high speeds.
3. How could I tell?
4. Not a bad idea, that way my leaks would not waste the expensive stuff

Jonesboro

The water pump is driven by a belt. Loosen or remove the belt so that it is not touching the water pump pulley. Try spinning the water pump pulley by hand. If it spins it is not seized.

Since you have another radiator handy, I would definitely swap it in and see what results you get.

thatoneguy

I have an new aluminum AST for sale. PM me if you're interested.

Brad

another way to check the water pump is get the car up to operating temp, or enough for the thermostat to open up then squeeze the upper radiator hose. If you feel pressure surge then the pump is flowing.