[V8] Overheating

[John Bysinger]

We've had a nice streak of warmer weather these last couple of weeks up here
in rainy washington, and it looks like the v8's not too happy with it.  I
got stuck in some stop and go traffic the other day and first noticed that
the v8 didn't want to shift, then checked the gauges and the temp 'seemed'
high, right around the 100 mark on the gauge (still a new car to me so I'm
not sure what the limits of normal and high are yet.)  I was able to get out
of the traffic and drive home at a decent, constant speed and noticed the
temp dropped back down to ~ 95 or so, but she still didn't want to shift.
I'm guessing the shifting was a 'limp home mode' when the ECU notices things
go awry, as it was in 4th and stayed that way until I shut it off and
started it back up that night and it shifted fine.

So now I've got a week off and time to put into figuring it out and started
it up in the driveway, the overflow tank doesn't seem low, and no big
puddles under the car so I tried starting her and letting it idle until
operating temp.  It took close to 30 minutes for it to reach a full
operating temp, with a slow climb on the gauge.  However it passed the 100
degree mark and I noticed the overflow tank showing signs of a pressure
buildup and leaking a small ammount through the fill cap, so I shut it down.

Two things I think may be contibuting but wanted to bounce it off of you
guys first.  One, the drivers side electric fan on the radiator wasn't
running, is this a secondary fan?  and should it have been?  Two, I'm
thinking it may be a stuck thermostat not opening properly, and I'm seeing
two possible thermostats available, a 180 degree and a 192/195 degree.
Which temp are you all running on yours?

And the last note, when pulling the airbox out of the way, I noticed the
previous owner had put one of those 'vortex' things in the openeing to the
throttle body.  I had to laugh a bit as there's a laminar flow grate right
behind it defeating the purpose.

-John
90v8q