Hello Fellows,

I found something out the hard way last night and I wanted to let everyone know about my experience to hopefully save some headaches for other brickboarders.

I was changing my thermostat last night. What should have been a simple job became more complicated when one of the housing bolts was so seized up that I stripped the torx grooves out of the bolt head trying to get it off.

The /real/ trouble came though, while I was trying to remedy that problem. I broke the lower thermostat housing.

WRONG COURSE OF ACTION:
In order to get the seized bolt out I reached for a chisel and hammer and tried to cut a groove in one size of the bolt and hoped to spin the bolt with the action of the chiselling.
This was a supremely boneheaded move and thinking back it was a)drastically out of character for me and b)exactly the wrong thing to do.

Some of you may know that the thermostat and what many of us will simply refer to as the 'thermostat housing' actually sit on top of a 'lower thermostat housing', which is a channeled piece of aluminum bolted to the block. This piece of aluminum is not particularly strong and NOT MEANT TO BE BEATEN REPEATEDLY WITH A HAMMER BY A STUPID NEANDERTHAL LIKE ME.

I of course broke the lower housing in half.

There were a number of very negative consequences to having a broken lower thermostat housing:
1 - the car is, for all intents and purposes, completely disabled. Driving it at all would lead to almost immediate overheating.

2 - getting this thing out is a supreme pain in the ass. On my car anyway, you have to first remove the power steering pump, which means you have to remove the serpentine drive belt first, which means you have to open the wheel well... Also, the pump is bolted on by way of 5 bolts, 2 of which are accessible only THROUGH THE HOLES IN THE PULLEY. Just like I said, PAIN IN THE ASS. I can only assume putting it back in will be just as much of a pain in the ass (I don't know how many times I need to repeat those three simple but perfectly adequate words in order to make sure you understand their magnitude in this situation).

3 - this is not something that breaks often, and thus you will almost certainly have to buy it from the dealer (for approx $100 + gasket) and they are actually unlikely to have it in stock which means they will need to order it from a warehouse somewhere, taking at least a business day to get it, and at most forever. So add expedited freight charges to your cost as well.

All for a $20 thermostat job. Sheesh!



PROPER COURSE OF ACTION:
I suppose any /sane/ person would have immediately reached for a drill to drill the head out/off the bolt. And this is, from what I can tell, the best course of action:
- start with a bit about the size of the bolt shaft, and drill as close to on-center as possible, as close to perpendicular as possible
- move up to larger and larger bits. Use the bolt-shaft sized bit to go deeper, then a larger one to widen the hole, then a larger one to widen the hole more, then back to the small bit, then larger, etc, etc
- try not to go deeper then the bolt head.
- eventually the bolt head will bust right off, you can remove the thermostat housing, and then twist the stuck bolt from the lower housing


LESSONS:
- DO NOT PUT ANY STRAIN ON THE LOWER THERMOSTAT HOUSING
- - it was not meant for pressure, strain, pounding, beating, pushing, or any other neanderthal-esque technique

- DRILL FIRST
- - I can't overemphasize how effective the drill job was. I was skeptical at first, and worried about ruining my upper thermostat housing, but I didn't mark it up a bit. I think if you're careful like I was you can get away without harming the upper housing whatsoever.

- USE PENETRATING OIL
- - it might not help - I used penetrating oil on those bolts for a couple of days leading up to the attempted job, and it didn't seem to do anything, but I think it should be considered a must

- GET A GOOD DRIVER
- - my torx-40 driver was less than fantastic quality. I am going to buy the best quality torx-40 driver I can find TODAY.
- - the longer the shaft the better. Mine is short, ~6 inches, and I managed, but jeez two more inches would have been a real blessing. 4 more would have just been awesome.


--
1998 V70 AWD Turbo 180k+