The following instructions will guide you through the process of installing a thermostat.
Allow the engine and coolant to cool down completely before attempting to change the thermostat. Failure to do so could result in serious burn injuries!Remove the old thermostat :
- Drain the cooling system or siphon out enough coolant to get the level below the top of the intake manifold.
- Remove the bolt holding the water neck in the manifold.
- Remove the water neck from the manifold with a slight rocking motion while pulling up.
- Pull up on the thermostat to remove it.
You should have two rubber seals for the new thermostat. The smaller one (not an O-ring) goes into the water neck. The O-ring goes into the groove on the outside of the water neck.
Install the new thermostat :
- Clean all surfaces on the water neck and manifold shiny clean.
- Install the thermostat - pointed end up.
- Install new thermostat seal.
Important thing is that the pellet (brass cylinder about 3/8" in diameter faces the engine but I don't think it will assemble properly otherwise.Install the water neck:
With all surfaces clean and liberal use of white grease, the neck should just push in by hand (I sometime push with a big screwdriver centered on the top. The bolt just holds it in place.
DO NOT try to pull the water neck down with the bolt. Torque the bolt to 10-12 lb-ft.
Note: a "wobble" 1/4" extension and a short 10mm 6 point socket make life a lot easier, the manifold flange is in exactly the wrong place for a straight down shot - obviously the engineer who designed it never had to remove one).I use 180F Stant "SuperStats" p/n 59848 usually in stock at Pep Boyz (plug) & just put one in the White car. My observation is that the SuperStat will hold to about +/- 1 degree of the set point where with a conventional 'stat it is more like 5 degrees, usually on the high side. It matters to me.
O-ring (Fel-Pro 0427 or equivalent) is always changed if the neck comes off (e.g. when flushing the coolant system) and it has been more than a month or two since replaced (Keep several on hand). If the inner rubber seal seems good I generally reuse them since it will not cause an external leak.
BTW there is a TSB on that inner gasket. Seems without it enough coolant could flow past the thermostat to make getting heat a lengthy process. Also 180F thermostat will generate more than enough heat even at 0F (observed) and will warm up to operating temperature just as fast as any other..