Where is the thermostat housing located?How do you change a thermostat on a Chevy Monte Carlo 3.8 liter v-6?I own a shop, and have owned a few 3.8 V-6 engines. Good engine! Follow the top radiator hose from the radiator to the engine. Remove the hose from the engine, this will be the thermostat housing that you remove the hose from. Two bolts hold this housing in place. You must remove these bolts, and may have to remove the alternator tensioner bracket in order to get to one of the bolts. After the housing is removed, remove the old thermostat, and scrape all the old gasket you can get off the intake and the housing. Clean out the recessed area where the thermostat goes to make sure the new thermostat will sit below the mounting area. Once you have it all ready to go back together, use a spared amount of RTV on the thermostat gasket, and the housing. This is to place the gasket in position, and to hold it there during installation. Once the RTV has dried, and the gasket has stuck in place, you are ready to install the thermostat. Put the bolts through the housing before the RTV has a chance to dry, and the bolts will hold it in place until it dries. On the thermostat or the box it came it, will be a picture or an arrow that shows the correct direction it is to be installed. This is important to the operation of the thermostat. Place the thermostat in the intake, and make sure it sits below the surface down in the slot. You can put just a tiny bit of RTV to keep it down if you wish, but let it dry before you attach the housing. Clean the mounting bolts with a wire brush, and if one or both of the bolts go through the intake, you will have to use a thread sealer (to keep it from leaking) on the bolts. Be careful when you install the bolts to not move the housing back and forth on the intake, as this sometimes will get the thermostat out of position. Tighten the bolts down evenly with your fingers, and then use a socket, extension, and a ratchet to just barely tighten the bolts. It is very important these bolts are tightened evenly, and that the thermostat doesn't get moved when doing this. If the thermostat gets out of position, and you tighten the bolts down, the housing will leak, and when you tighten it down more to stop the leaking, it will break the housing because it is pulling down at an angle. Before you start the job, drain about a gollon of coolant from the radiator drain plug on the drivers side, facing the engine. This plug is hard to get to, and should turn counter clockwise to loosen it, but do keep in mind that some of them do work the other way, so be careful to not break it. Once you have the housing back down, the top radiator hose back on %26amp; tight, you can put the coolant back into the radiator. You may not can get it all back in until the engine has been ran long enough for the top radiatior hose to be hot. This indicates the thermostat is open, and you should be able to get the rest into the radiator, and the cap back on.
Glad to help out, Good Luck!!!How do you change a thermostat on a Chevy Monte Carlo 3.8 liter v-6?Simply take your VIN (serial number) to any GM dealer's parts department and ask them for a print out of the area in question.They will provide you with a diagram from their automated parts catalog which will show you what you need.It's not a difficult as some would have you believe.