# Thermostat bolt broken



## MikeSteward (Feb 4, 2010)

I replaced the thermostat on my 97 Maxima today. Then I noticed it was leaking coolant. So, I assumed I had not tightened it down enough. After a few more turns, one of the bolts snapped off. Are these bolts made into the casing, or can they be removed?


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## MikeSteward (Feb 4, 2010)

*Disappointed*

Wow. My post has been viewed 16 times, and with no responses in 24 hrs. Not even a "sorry buddy, you're SOL." I would have thought that a forum dedicated to Nissans would prove more useful. I'm disappointed.:lame:


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## 4thGenTinkerer (Nov 1, 2009)

Welcome to the Forum! Ok, you have a problem. The studs that the nuts screw onto are part of the block. I would remove the T-stat and see if the stud that broke can be removed. I cant tell you if the studs are threaded or cast into the block. If they are threaded (most likely they are) you might have a chance to grab the broken stud and remove it. If it is cast into the block or broken off flush with the gasket surface you will have to drill out the broken stud and use a tap and die to re-thread the stud hole and install a new stud. Maybe a helicoil set would help. Either way, you are facing a real pain in the ass. Removing the radiator will give you more room to work. Drain coolant, disconnect tranny cooler lines, disconnect wire harness for fans, disconnect coolant hoses, pull radiator out. Be careful when drilling the broken stud out. Dont drill too deep. Hope this helps, Good luck and if this seems like more than you are willing to deal with, take it to a good mechanic.


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## pulsar86 (Aug 13, 2009)

Welcome to the forums. If the stud has grown in [ corrosion between dissimilar metals] most likely easyouts won't be able to be used to remove it and the stud will have to be drilled out. If the surrounding metal is too corroded the area may need welding, redrilling and a new thread made. Probably a job best done by an engineering shop I'm afraid. as said if you are going to try to remove the stud by drilling be very careful as you may cause more problems if you get off centre.


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## MikeSteward (Feb 4, 2010)

Thanks for the suggestions guys. I was actually able to borrow a tool from autozone called a stud remover. This tool is like a socket, except it has bearings inside that spin around the bolt. As they spin they cause the tool to clamp down on the stud in much the same way that a drill clamps down on a bit. I used the 6 millimeter stud remover, and it fit the stud perfectly, so no easy outs or drilling were necessary. However, I did have to remove the bolt that held the alternator up in order to have enough room to get the tool around the stud. Once on, the stud came out easily enough. The tool smashed the threads up pretty good, but it wasn't like I was going to be using the stud again anyway. I was disappointed when I got to the Nissan dealership and found that they had no clue what the stud was, even when I showed it to them. They were also unable to order it for me, not even as a special order part. I wound up going to a local hardware store (not lowes or home depot, a real hardware store) and having them cut an automotive bolt down to the same length as the stud was originally (cost me 47 cents). The threading was an identical match, which is really important. I used 3 nuts to install the stud. The original stud was beveled and unthreaded in the middle, so that the beveled portion would cause the stud to stop before it went too far into the thermostat housing. Since I did not have a beveled stud, I used the first nut to prevent the housing end of the stud from going in too far. I placed the other two nuts on the thermostat end of the stud, so that the outer nut would catch on the second nut and I could drive the stud in with a socket. The stud went in without a hitch, and I carefully removed the three nuts. I replaced the thermostat gasket, installed the thermostat, and screwed the original nuts back onto the thermostat. The alternator also reconnected without much difficulty. I have been driving it for three days now and the thermostat is working perfectly. I am not leaking any fluid or running hot. I hope this information is beneficial to the next guy with my problem. :woowoo:


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## 4thGenTinkerer (Nov 1, 2009)

Good deal! Glad you were able to remove the stud. i kinda figured it would be a given to drop the alternator out of the way. Either way congrats on your fix. Thanks for posting the details as well. Job well done.


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## pulsar86 (Aug 13, 2009)

Well done, glad you had enough stud to be able to use the remover, usually they break off flush with the surface to make things more interesting. Hope you used antisieze on everything when you put it back together to make things easy if you ever have to take it apart again. Happy motoring.


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