Tried to replace thermostat broke both fastening bolts to the hou

Drill a hole down the center of the bolt and use a bolt extractor

remove the alternator and if there is enough of the bolt take a pair of vise grips lock them down tight and remove bolt, if it is a clean break you have a few options:

1) get a set of easy outs, drill a hole and use an easy out to exact broken bolt

2) get an oversize self tapping bolt (a size bigger then the bolt that broke off, drill the bolt out completely and then tap the new bolt

Good Luck Tim

ok witch bolt is it. On most tuff bolts that I break trying to remove or install I use a left hand drill bit and then if that does not catch and remove I use an easy out but let it soak for a while with some WD-40 first

there is a new kind of easy out .. the old left hand spiral design doesnt work somtimes .. the new one is much better (more of a straight rib) ... use penitrating oil a few hours before attempting to remove ..

in an emergency you can use "liquid gasket" you can get that at any auto parts store (use non perminant version) .. apply that to both sides of the gasket .. make it thick enough to fill the gap ..bolt down snug let cure before use .. ... but the loss of one bolt will eventually crack the boss on the remaining side .. so its a good idea to fix the problem .. you can usually get the old bolt out with the new easy out but if you cant . then just drill a hole thru the broken bolt and use a tap to make new threads for a smaller size bolt with washer ... make sure the new bolt doesnt bottom out ...

If the bolts broke off inside the engine block they must be extracted, buy a easy out set of bolt extractors choose the appropriate size drill to use in relation to the broken bolt to be removed then dril a hole through the old broken off peice remaining inside the bock take the easy out extrctor and push it into the drilled hole then tap it into the hole firmly proceed to tur n the extractor counter clockwise to remove the broken off peice. whatever you do don't use an extractor that is too large it may not work you can always go up on the size later.

This is what it would take to replace it:

2.2L (VIN 4) Engine

1. Drain the cooling system.
   
2. Remove the lower radiator hose from thermostat outlet.
   

Remove the thermostat outlet bolts and outlet

3. Remove the thermostat outlet bolts and outlet.


Remove the thermostat

1. Remove the thermostat.
   
2. Clean the mating surfaces of the radiator outlet and the radiator outlet pipe.
   

To install:

1. Install the thermostat.
   
2. Install the thermostat outlet and bolts.
   NOTE Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
   
   
3. Install the coolant outlet attaching bolts and tighten the thermostat outlet bolts to 10 ft. lbs. (14 Nm).
   
4. Install the lower radiator hose to thermostat outlet.
   
5. Fill the cooling system.
   
6. Inspect for leaks.
   

That's because of corrosion. It happens!

The broken studs have to be cut, or ground down flush, with the thermostat housing. Then a center punch is used to make a deep dimple, in the center of the broken stud.

Next use a small drill bit to make a pilot hole.
Two times smaller than the stud. (Bolt)
Use caution, as you don't want the drill bit to walk off to one side. Keep the drill level, and vertical.

Now come back with a larger drill bit, but one that is smaller than the stud/bolt, and will stay away from the threads. Try to drill at least one-half inch in depth. Use an Easy Out, bolt extractor.

If it feels as though the Easy Out bolt extractor, is being forced too much, and you think there is a possibility of it breaking, STOP!
Use a drill bit that is large enough, to drill a hole that will not touch the threads. Then work a small chisel along the outside edges of the bolt 'Shell', and work that thin shell to the inside. Use a pair of needle nose pliers to try to extract the shell out. One piece at a time.

(After you have drilled the center of a stud, or bolt, out to where the threads are, there is a thin metal shell left behind)

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.

Hello, The only thing you can do is weld the broken area and the drill and tap the hole.
Go to http://www.durafix.com/ and they have a solution for you. Good luck and let me know how you make out.