How do you get to the bottom bolt on the thermostat housing of a 1999 Olds Silhouette?

Answer 1

I have a 98 Silhouette, and just got done with new head gaskets, and valve job. Of course pulling both cylinder heads is quite involved, but exposes the thermostat housing. The real question is why do you want to replace the thermostat, if your overheating it's probably not the problem. First I would suggest buying the Haynes Service manual for your car, $20 and worth every penny, I have the $150 GM Service Manual and prefer the Haynes. To get at the thermostat housing try removing the Air Cleaner and intake plumming, then the throttle body, you'll have trouble with the small water hoses going to the TB, you may just want to cut and plug them, I've been told that they arn't needed, but the're sure a pain in the butt. Check the manual, I don't have mine available now, but that's the easiest way,-- you don't want to know the other way. Now back to why are you replacing the thermostat. This car has a history of coolent leaks in the lower intake manifold, and I lost my first head gasket at around 100K Mi. Aluminum heads and cast iron blocks are prown to gasket failures, if your getting bubbles into the coolent recovery tank or water in the oil(looks like dirty mayo on the dip stick) then you probably have a head gasket leak. If you think you've gotten air in the cooling system try bleeding the system. There are two small brass bleed screws, one on the thermostat housing, and one near the water pump on a black coolent manifold. With the engine running and warm take a socket or nut driver and lossen each nut until you get a steady stream of coolent, carefull it's hot. This allows the air to escape and speeds the flow of coolent. If you have to do this repeatedly there is air getting into the system from somewhere, probably from the combustion chamber, and that means a blown head gasket. Changing a head gasket is not really that hard, if you know how to rotate the engine, find the hidden bolt(there's always one), take lots of pictures and mark the cables, although all of the plugs and sockets are different so you can't get them mixed up. If you think this is your problem, repost and we can discuss what needs to be done, give yourself a couple of weeks, and do everything, plugs, wires, O2 Sensor while your at it. See ya 94