How do you replace the thermostat located on a 1996 Oldsmobile Cutlass Supreme 3.1L?

Answer 1

Thermostat replacement on 96 cutlass supreme 3.1 liter:

First thing I can tell you is give yourself plenty of time to do this simple job. Its not really difficult but can be especially trying if your time is limited. Change the thermostat when the engine is cold. Drain about 3 quarts of coolant from the cooling system and save it. Remove the air intake hose from the filter canister to the throttle body.( 2 clamps ) Remove the throttle cable and cruise cables by gently prying them off the throttle body butterfly arm. Remove the spring between the throttle body arm and the throttle cable bracket. Remove the (10mm nut) from the rear of the bracket. ( its on a stud used where the egr tubing attaches ) Remove the 2 8mm head bolts from the bracket near the front where it attaches to the throttle body. Remove the 13mm nut (using a socket) from the bottom of the throttle bracket attaching it to the manifold. As I remember there possibly is another bolt near and to the rear there also. Remove the clamp holding the fuel lines to this bracket. You shuld now be able to remove the throttle bracket and set it aside while getting to the thermostat. There are 2 bolts holding the thermostat housing in place. The easy one is forward top and can be reached with a short socket (13mm) and wobble extention or universal joint. The trying one is to the rear and lower. There is very limited space between the 13mm bolt head and the exhaust crossover pipe. The bolt is very trying to remove and get started again. Fortunatly the lower mounting hole of the thermostat housing is usually slotted. Using a 12 point 13mm box wrench, (or better yet if you have one) a 13mm crowfoot, back out this bolt as far as you can without removing it.( 1/12th of turn at a time ) With some aggravation and manuvering the housing will come off and out with the thermostat staying in the manifold. If the thermostat tries to come out with the housing the housing can't be removed due to space limitations. Use a screwdriver or similar small tool to hold the thermostat in the manifold cavity until the housing is free. Now the thermostat and rubber sealing ring will come out. The rubber ring usually comes with a new thermostat so no gasket is requred. As ALL the manuals read" REVERSE PROCEEDURE TO INSTALL "