[V8] Thermostat

urq urq at pacbell.net
Wed Jul 25 18:19:12 EDT 2007

... don't have an engine in front of me, but I'm pretty sure the thermostat
is on the lower rad hose fitting ... not a real big deal, you can only
remove the flange which has a thermostat behind it ... :-)

The upper rad hose is expensive, and rather delicate IME, I damaged an
almost brand new part by leaving one of the fittings attached to the head
while I did the thermostat ... not too long after that I had the hose fail
... for that reason I recommend removing the upper rad hose when you do the

The bolts on the flange are Torx heads ... and they can get corroded into
place pretty hard ... it might be best to hit the heads with some
penetrating oil before starting ... 

Steve B
San José, CA (USA)

-----Original Message-----

On the front of the engine, down a little, a bit over toward the
passenger side.  Follow the upper rad hose to it.  It comes out the
passenger side top of the rad, splits and goes right to each side of
the engine.  You want the passenger side one.

If you remove the idle stabilizer valve you'll have more room to work.
Three 10mm acorn nuts and unclip the connector and it should come out
If you have the belly pan on, be extra careful not to drop the nuts.

You can drain the majority of the coolant from the drain on the rad.
It's way down low on the passenger side.
Get down and look through the grills below the main bumper surface.
You should see a blue plastic knob about the size of a quarter with an X on
You can use a large blade screwdriver to unscrew that.
Be carefull, it's plastic and old.

Disconnect both arms of the upper rad hose and swing them out of the
way.  Be gentle, a new hose is 150 bux.  You're still going to lose
some fluid here, so be ready.

The thermostat housing has two bolts that have torx heads on them.
Again, if your belly pan is on, be extra careful to not drop these bolts.
The torque spec is fairly low so don't be too agressive when you reassemble.
Be sure to get a new rubber gasket with the new thermostat.
Some come with, some are sold separately.

The correct thermostat has a little check valve in the lip.
That should be at the top when the thermo is installed.
You don't need any goo for the gasket.
It gets compressed and seals by torquing the thermostat housing down.

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