Broken thermostat bolt
Thread Starter
Racer
Joined: Oct 2009
Posts: 286
Likes: 0
From: Brooks GA
Broken thermostat bolt
Well if I had any luck it would be BAD LUCK. Heading to work this morning in my 84 the temp gauge was going up. I pulled off and found a gas station. Opened up the hood and the top radiator hose is collapsed. Well that tells me the thermostat has gone bad. Made it back home and fired up the C6 and went to work. Bought a new thermostat with the intent to swap it out. I mean how hard could it be right. I remove the air cleaner and remove the top radiator hose. Start on the bolts to the goose neck. First one was difficult but it came out. the second bolt was much more difficult and yes Murphy was gunning for me and the bolt broke. I have a back out kit. I was making good progress and sure as all get out Murphy shows up again and the back out broke off inside. Now I am to the point of having it towed and fixed or spend $600 for a Renegade Intake not counting the install. I have not called Corvette Country in Fayeteville Ga. yet to see if he has one and the cost. Any suggestions???
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
well, IF the bolt broke backing OUT, and then the back-out tool broke because the bolt is more or less frozen in place....
there are 2 options at this point from what I see...
drill it out and tap a new thread and get metal shavings all over the place...and IN everything....
or
pull the intake off to replace or repair it the RIGHT way.
Either way, you're screwed like a pooch.
Sorry 'bout that. Just a bad day to be you, that's all. Tomorrow should be better...
Good luck !
there are 2 options at this point from what I see...
drill it out and tap a new thread and get metal shavings all over the place...and IN everything....
or
pull the intake off to replace or repair it the RIGHT way.
Either way, you're screwed like a pooch.
Sorry 'bout that. Just a bad day to be you, that's all. Tomorrow should be better...
Good luck !
Le Mans Master
Joined: Jul 2004
Posts: 6,228
Likes: 698
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
had the exact same thing happen with my 85 about 10 years ago. I tried drilling out the bolt and then tapping it. I broke the tap off in the hole. Sure didn't know what to do. Put it back together as tight as I dared with 1 bolt, filled with water, and drove the 2 miles to the local Chev dealer. They got it out somehow and put a stud in the repaired hole.
Cost was $130 as I recall and smiling when I paid it.
Cost was $130 as I recall and smiling when I paid it.
Last edited by Cruisinfanatic; Nov 3, 2014 at 09:52 PM.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I have a CFI intake for sale, if it comes to that point for you. Posting for that is HERE.
As for removing the bolt...and the extractor, HEAT is your friend. HEAT.
If you have access to a welder, you can weld up a "pile" on the broken off parts, then while it's hot grab the "pile" with Vise Grips and thread it out. It may help to heat the area of the casting w/a torch while welding and removing, since aluminum removes heat so quickly.
It MAY take the thread out w/it. That is not ideal, but it's O.K. as it still gets the bolt out, and you can helicoil it to return it to service.
The other option is to drill it out, but with the mixed metals in there now I'd think your chances of getting a straight and centered drill hole are pretty small. IIWM, I'd fire up my torch and my MIG and start welding. Drilling shavings are not an issue here; they aren't going anywhere that will hurt anything.
Either method could be done on the car.
As for removing the bolt...and the extractor, HEAT is your friend. HEAT.
If you have access to a welder, you can weld up a "pile" on the broken off parts, then while it's hot grab the "pile" with Vise Grips and thread it out. It may help to heat the area of the casting w/a torch while welding and removing, since aluminum removes heat so quickly.
It MAY take the thread out w/it. That is not ideal, but it's O.K. as it still gets the bolt out, and you can helicoil it to return it to service.
The other option is to drill it out, but with the mixed metals in there now I'd think your chances of getting a straight and centered drill hole are pretty small. IIWM, I'd fire up my torch and my MIG and start welding. Drilling shavings are not an issue here; they aren't going anywhere that will hurt anything.
Either method could be done on the car.
Last edited by Tom400CFI; Nov 3, 2014 at 11:45 PM.
Advanced
Joined: Oct 2001
Posts: 55
Likes: 0
From: Seminole FL
Not trying to hijack this thread but the same thing happened to me last week. The rear bolt broke off level with the intake. Trying to remove the plenum now as I cant get a drill in there to drill it out. Everything, bolts and wires and hoses have been removed/disconnected except for the lower intake runner bolts. I need a long thin t-40 bit before I can loosen 2 of the bottom drivers side bolts. I've tried pulling the plenum up but it is still firmly attached. Wow. Hope I can drill it out. Will try lots of pb blaster then heat before I attempt to back it out......Any advice is greatly appreciated. I don't want to tow this thing to a shop....
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
With a Screw Extractor broke off . I'd say now it and everything in that hole needs to be burned out with water from a EDM Machine. Aluminum has a higher melting point than metal and the water trick will save that Manifold.
Cost about 20 bucks plus manifold Gaskts and your free labor
Cost about 20 bucks plus manifold Gaskts and your free labor
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Advanced
Joined: Oct 2001
Posts: 55
Likes: 0
From: Seminole FL
Tom400cfi, I am talking about the rear thermostat housing bolt. I'm attempting to do the same thing the original poster is doing. Not sure which of his 2 bolts broke off. I'm still trying to get the plenum off so I can get a drill on top of the broken off bolt. Once I reach that point then I will put a torch, I don't have a welder, to the area around the broken off bolt before I try to back it out to avoid breaking the extractor off inside...thx for the info....
Race Director
Joined: Feb 2002
Posts: 11,616
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From: Compound in the Grove, Ga.
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Looks like the ones Tom400CFI has FS are a great deal easiest fix.
Thread Starter
Racer
Joined: Oct 2009
Posts: 286
Likes: 0
From: Brooks GA
I have a CFI intake for sale, if it comes to that point for you. Posting for that is HERE.
As for removing the bolt...and the extractor, HEAT is your friend. HEAT.
If you have access to a welder, you can weld up a "pile" on the broken off parts, then while it's hot grab the "pile" with Vise Grips and thread it out. It may help to heat the area of the casting w/a torch while welding and removing, since aluminum removes heat so quickly.
It MAY take the thread out w/it. That is not ideal, but it's O.K. as it still gets the bolt out, and you can helicoil it to return it to service.
The other option is to drill it out, but with the mixed metals in there now I'd think your chances of getting a straight and centered drill hole are pretty small. IIWM, I'd fire up my torch and my MIG and start welding. Drilling shavings are not an issue here; they aren't going anywhere that will hurt anything.
Either method could be done on the car.
As for removing the bolt...and the extractor, HEAT is your friend. HEAT.
If you have access to a welder, you can weld up a "pile" on the broken off parts, then while it's hot grab the "pile" with Vise Grips and thread it out. It may help to heat the area of the casting w/a torch while welding and removing, since aluminum removes heat so quickly.
It MAY take the thread out w/it. That is not ideal, but it's O.K. as it still gets the bolt out, and you can helicoil it to return it to service.
The other option is to drill it out, but with the mixed metals in there now I'd think your chances of getting a straight and centered drill hole are pretty small. IIWM, I'd fire up my torch and my MIG and start welding. Drilling shavings are not an issue here; they aren't going anywhere that will hurt anything.
Either method could be done on the car.
Racer
Joined: Apr 2010
Posts: 372
Likes: 23
From: Harper Woods MI
I had the same issue with my '84 a couple of years ago. What I thought would be a simple thermostat replacement turned into several days of trying to get the broken bolt out. I ended up drilling out the broken bolt and tapping in a new Helicoil thread.
Burning Brakes
Joined: Jul 2014
Posts: 1,194
Likes: 2
Sounds like you had the bolt moving in the right direction.
Before I removed anything I would try to tap it around to tighten and then heat the bolt and surrounding area then touch a candle to the top of the broken stud and melt some wax over it with the intention of the melted wax being sucked into the threads, much like solder being sucked into a copper pipe joint.
Then I would try to tap the bolt out with a small drift or whatever I could get a bite on.
As some one mentioned above, place nut over broken bolt and weld inside nut until weld is flush with top of nut. You have to make sure you get down to the broken stud and that you're set hot enough, then just put a wrench on it and if done properly the bolt will back out.
If the bolt starts to come out and then get tight again, melt the candle wax on the bolt as stated above and keep easing it out.
Before I removed anything I would try to tap it around to tighten and then heat the bolt and surrounding area then touch a candle to the top of the broken stud and melt some wax over it with the intention of the melted wax being sucked into the threads, much like solder being sucked into a copper pipe joint.
Then I would try to tap the bolt out with a small drift or whatever I could get a bite on.
As some one mentioned above, place nut over broken bolt and weld inside nut until weld is flush with top of nut. You have to make sure you get down to the broken stud and that you're set hot enough, then just put a wrench on it and if done properly the bolt will back out.
If the bolt starts to come out and then get tight again, melt the candle wax on the bolt as stated above and keep easing it out.