How do you replace 2004 Buick Century thermostat?

Answer 1

First step is drain the cooling system. Follow the upper radiator hose to the thermostat housing. Remove the clamp from the hose and remove the hose from the housing. You have two bolts holding the thermostat housing onto the block, remove both bolts. The upper bolt can be taken out with a ratchet (13mm) but the lower on is going to give you problems. You will need to remove it with a combination 13mm wrench. Because this area is so hard to get at it will take some time to remove but you can get it out. Once both bolts have been removed you can pull off the thermostat housing. You will notice that the housing has one hole for the upper bolt and a slot for the lower bolt. This is what is going to save you a lot of pain later on. Here's the trick to putting it together. Don't use the same bolt on the lower block. Get a bolt that is at least a quarter inch longer. The length isn't going to matter because the bolt goes all the way through the mount. You will now hand thread the lower bolt a couple of turns to hold it into the housing. Put a little grease on the rubber seal to keep the thermostat from falling out of the housing and install the new thermostat. Because the lower bolt goes into a slot and because it is longer then the original bolt you can actually work the thermostat housing against the exhaust heat shield and over the thermostat that is sticking out of the housing and slid the slot onto the lower bolt. Then tighten the bolts down. This will take some time but it will save you a chunk of change. You now owe me a beer.