[V8] Thermostat

Scott Simmons indischrot at gmail.com
Wed Jul 25 22:43:22 EDT 2007

It's probably too late, but I did this on Monday.

I left the upper rad hose on, but took off the ISV, IAT sensor, and the 
connector for the TPS.  Moved wiring out of the way.  Drained as much 
fluid from the radiator as it would.  Removed the two T30 bolts.  
Wiggled lower rad hose out of the way.  Another quart coolant gushed out 
upon removal of thermostat.  Replaced 92*C with 87*C.  Replace sealing 
ring.  Replaced everything.  

I lost about a gallon and a half of fluid.  Maybe a bit less.  Made sure 
car was level.  Added fluid.  Started car.  Added fluid.  Turned on 
heater.  Added fluid.  Took for test drive and was startled by the damn 
Coolant symbol blinking in red.  Added a few cups more.  All is well.

Easier than a 944, but hardly "easy."  =)

~Scott S.

urq wrote:

>... 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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