Trouble shooting Replaced the intake manifold because the thermostat housing had been broke off where the bolts attach the thermostat to the manifold. After putting the engine back together, I started the car and now there is a loud popping sound coming from the engine. Any ideas on what would be causing this?

hermostat, Replace My database showed this for thermostat removal, if database is wrong, my bad. 1. Remove coolant expansion tank cap. 2. Raise and support vehicle. 3. Open radiator drain petcock and drain engine coolant into a suitable container. 4. Close radiator drain petcock and lower vehicle. 5. Remove upper engine cover. 6. Remove protective shield from under engine. 7. Detach and remove air intake tube from throttle body and air filter housing. 8. Disconnect electrical and vacuum connections from intake manifold and its attached components. 9. Remove fasteners at bottom of intake manifold and at connection to cylinder head. 10. Remove intake manifold. 11. Disconnect hoses from thermostat housing. 12. Disconnect coolant temperature sensor electrical connection. 13. Remove thermostat housing from cylinder head. 14. Remove thermostat and gasket from thermostat housing cover. 15. Reverse procedure to install, noting the following: a. Install new thermostat housing gasket. b. Torque thermostat housing bolts to 88 in. lbs. c. Torque intake manifold bolts to 13 ft. lbs. d. Fill and inspect coolant level.

3.4L Engine

1. Remove the thermostat housing to intake manifold bolts.
   
2. Remove the thermostat housing outlet and thermostat

3.1L Engine

1. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.
   
2. Remove the thermostat.

2.2L Engine

1. Remove the thermostat housing to water pump feed pipe bolts.
   
2. Remove the thermostat housing to water pump feed pipe.
   
3. Remove the thermostat.

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

Follow the upper rad hose to where it meets the engine.The hose is attached to the thermostat housing,just tucked under the exhaust crossover pipe.

It's under the housing shown below on the back side of the engine. Instructions taken from autozone.com. I recommend you also read my post at http://www.fixya.com/cars/r5929960-s_thermostat and let me know if you have any questions.

3.1L Engine

1. Disconnect the negative battery cable.
2. Drain the cooling system, into a suitable container, to a level below the thermostat housing.
3. Remove the air cleaner assembly.
4. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.

Fig. Remove the two housing-to-intake manifold bolts and remove the housing

1. Remove the thermostat.

To install:

1. Clean all gasket surfaces completely.
2. Insert the thermostat in the intake manifold.
3. Attach the thermostat housing to the intake manifold.
4. Install the mounting bolt and nut. Tighten to 18 ft. lbs. (25 Nm)
5. Install the air cleaner assembly.
6. Connect the surge tank line to thermostat housing.
7. Refill the cooling system.
8. Connect the negative battery cable, remove the radiator cap, then start the engine. Allow the engine to run with radiator cap removed, until the upper radiator hose becomes hot (thermostat open). With the engine idling, add coolant to the radiator until the level is up to the bottom of the filler neck.
9. Install the radiator cap, making sure the arrows line up with the overflow tube.

Not sure which engine you have so please pick the appropriate engine:

2.2L Engine

1. If equipped with an automatic transaxle, remove the exhaust manifold, as outlined in this section.
   
2. Drain the cooling system.
   
3. Remove the thermostat housing to water pump feed pipe bolts.
   
4. Remove the thermostat housing to water pump feed pipe.
   

Thermostat mounting-2.2L engine


3.1L Engines

1. Disconnect the negative battery cable.
   
2. Drain the cooling system to a level below the thermostat housing.
   
3. Remove the air cleaner assembly.
   
4. Disconnect the surge tank line from the thermostat housing.
   
5. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.
   
6. Remove the thermostat.
   

3.4L Engine

1. Drain the cooling system.
   
2. Remove the air cleaner.
   
3. Remove exhaust crossover pipe.
   
4. Disconnect the surge tank line fitting from the coolant outlet.
   
5. Remove the thermostat housing to intake manifold bolts.
   
6. Remove the thermostat housing outlet and thermostat
   
7. Clean the mating surfaces.
   

from autozone.com

2.2L Engine

1. If equipped with an automatic transaxle, remove the exhaust manifold, as outlined in this section.
2. Drain the cooling system.
3. Remove the thermostat housing to water pump feed pipe bolts.
4. Remove the thermostat housing to water pump feed pipe.
   

1. Fig. Thermostat mounting-2.2L engine
3. Remove the thermostat.
4. 
   

To install:

1. Install the thermostat.
2. Install the thermostat housing to water pump feed pipe.
3. Install the thermostat housing to water pump feed pipe bolt. Tighten the thermostat housing to water pump feed pipe bolt to 89 inch lbs. (10 Nm).
4. If equipped with an automatic transaxle, install the exhaust manifold, as outlined in this section.
5. Fill the cooling system.

3.1L Engines

1. Disconnect the negative battery cable.
2. Drain the cooling system to a level below the thermostat housing.
3. Remove the air cleaner assembly.
4. Disconnect the surge tank line from the thermostat housing.
5. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.
6. Remove the thermostat.

To install:

1. Clean all gasket surfaces completely.
2. Insert the thermostat in the intake manifold.
3. Attach the thermostat housing to the intake manifold.
4. Install the mounting bolt and nut. Tighten to 18 ft. lbs. (25 Nm).
5. Install the air cleaner assembly.
6. Connect the surge tank line to thermostat housing.
7. Refill the cooling system.
8. Connect the negative battery cable, remove the radiator cap, then start the engine. Allow the engine to run with radiator cap removed, until the upper radiator hose becomes hot (thermostat open). With the engine idling, add coolant to the radiator until the level is up to the bottom of the filler neck.
9. Install the radiator cap, making sure the arrows line up with the overflow tube.

Hi,

The thermostat is located in the forward most part of the intake manifold directly in the center. It is located in an in-closed housing with 2 studded bolts.

Simply follow the Large water pump hose on top of the intake manifold to it. You don't need to remove this housing,


just remove the 2 bolts and lift up the housing with the large hose attached to it.


The thermostat will be sitting in the recessed area of the hole in the intake manifold.



Good luck...

Alero, Grand Am 1999-2005 Thermostat - Removal & Installation 2.2L Engine

1. If equipped with an automatic transaxle, remove the exhaust manifold, as outlined in this section.
2. Drain the cooling system.
3. Remove the thermostat housing to water pump feed pipe bolts.
4. Remove the thermostat housing to water pump feed pipe.
   
   
   Fig. Thermostat mounting-2.2L engine
   
5. Remove the thermostat.

To install:

1. Install the thermostat.
2. Install the thermostat housing to water pump feed pipe.
3. Install the thermostat housing to water pump feed pipe bolt. Tighten the thermostat housing to water pump feed pipe bolt to 89 inch lbs. (10 Nm).
4. If equipped with an automatic transaxle, install the exhaust manifold, as outlined in this section.
5. Fill the cooling system.

3.1L Engines

1. Disconnect the negative battery cable.
2. Drain the cooling system to a level below the thermostat housing.
3. Remove the air cleaner assembly.
4. Disconnect the surge tank line from the thermostat housing.
5. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.
6. Remove the thermostat.

To install:

1. Clean all gasket surfaces completely.
2. Insert the thermostat in the intake manifold.
3. Attach the thermostat housing to the intake manifold.
4. Install the mounting bolt and nut. Tighten to 18 ft. lbs. (25 Nm).
5. Install the air cleaner assembly.
6. Connect the surge tank line to thermostat housing.
7. Refill the cooling system.
8. Connect the negative battery cable, remove the radiator cap, then start the engine. Allow the engine to run with radiator cap removed, until the upper radiator hose becomes hot (thermostat open). With the engine idling, add coolant to the radiator until the level is up to the bottom of the filler neck.
9. Install the radiator cap, making sure the arrows line up with the overflow tube.

3.4L Engine

1. Drain the cooling system.
2. Remove the air cleaner.
3. Remove exhaust crossover pipe.
4. Disconnect the surge tank line fitting from the coolant outlet.
5. Remove the thermostat housing to intake manifold bolts.
6. Remove the thermostat housing outlet and thermostat
7. Clean the mating surfaces.

To install:

1. Install the thermostat and housing outlet.
2. Install the thermostat housing bolts. Tighten the thermostat housing bolts to 18 ft. lbs. (25 Nm).
3. Install exhaust crossover pipe.
4. Connect the surge tank line fitting to the coolant outlet. Tighten the fittings to 15 ft. lbs. (21 Nm).
5. Install the air cleaner.
6. Fill the cooling system.
7. Inspect the system for leaks.

Hope this help (remember comment and rated this).

This is for 3.1L....if this is not what you have, please let me know the size of the motor!

3.1L Engines

1. Disconnect the negative battery cable.
   
2. Drain the cooling system, into a suitable container, to a level below the thermostat housing.
   
3. Remove the air cleaner assembly.
   
4. Remove thermostat housing-to-intake manifold attaching bolt and nut, then remove the housing.
   

Remove the two housing-to-intake manifold bolts and remove the housing

1. Remove the thermostat.
   

To install:

1. Clean all gasket surfaces completely.
   
2. Insert the thermostat in the intake manifold.
   
3. Attach the thermostat housing to the intake manifold.
   
4. Install the mounting bolt and nut. Tighten to 18 ft. lbs. (25 Nm)
   
5. Install the air cleaner assembly.
   
6. Connect the surge tank line to thermostat housing.
   
7. Refill the cooling system.
   
8. Connect the negative battery cable, remove the radiator cap, then start the engine. Allow the engine to run with radiator cap removed, until the upper radiator hose becomes hot (thermostat open). With the engine idling, add coolant to the radiator until the level is up to the bottom of the filler neck.
   
9. Install the radiator cap, making sure the arrows line up with the overflow tube.
   

You need to remove the thermostat housing again. Then you will have to extract the bolts you broke off. You will need to drill and tap them so you can use an easy out to remove the broken bolts from the threads. Then you can clean up both mating surfaces and replace the gasket and the thermostat. Check to make sure you did not crack the thermostat housing or you may have another leak when finished. They are usually aluminum and break easily if too much pressure is applied or they are corroded and weak.