[V8] Replacing the thermostat

[John Bysinger]

Tomorrow I'm picking up a new thermostat for our '90/3.6L V8Q.  Over the
weekend she ran a little hot (125C on the dash guage, oil temp never
wavered), and hasn't wanted to run back at the normal temps since.  Coolant
was low, but I don't know if that was before it overheated or because it
did overheat.  The pressure relief cap on the reserve tank under the hood
was doing it's job and venting over pressure in the system.  This kind of
symptom on other cars I've owned has always been a stuck thermostat.  But
there's always great advice here, so I thought I would check in to see if
there's anything I'm missing, or any advice on replacing the thermostat, I
checked my email archives from here and it seems to match the symptoms.  It
seems a fairly straight forward procedure, right on the passenger side
front of the block.  Any tips are welcome.

Conditions when it overheated were very low stress, I was driving to a tire
shop on the spare so I was taking it very easy.  45MPH on a straight/flat,
about 15 minutes down the road from a cold start at home.  Once I got it
home, first thing I checked was the auxiliary fan, since I've had to
replace it's fusible link before.  No issues, runs through it's cycles
fine, including hurricane simulation speed, and does kick on when the temp
climbs above normal.

As always, Thanks!

-John
1990 V8Q
john at bysinger.net