Bonehead move on Thermostat
Thread Starter
Racer
Joined: Feb 2012
Posts: 390
Likes: 1
From: Livonia MI
Bonehead move on Thermostat
Well, I really screwed it up this time. I needed to replace my thermostat, so I was loosening one of the thermostat housing bolts. Well, it was rusted in there pretty good and I snapped the head right off.
Since I was already screwed, to I decided to take the other one off. It looked like a stud with a nut on it, so I tried to remove it and *SNAP* it broke too. (Obviously these bolts had not been removed in forever.)
The good news is that the thermostat housing came off but now I'm left with this:
How the hell do I get what remains of those bolts out of the intake manifold?
Since I was already screwed, to I decided to take the other one off. It looked like a stud with a nut on it, so I tried to remove it and *SNAP* it broke too. (Obviously these bolts had not been removed in forever.)
The good news is that the thermostat housing came off but now I'm left with this:
How the hell do I get what remains of those bolts out of the intake manifold?
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
wow, atleast your consistant !
your gonna have to drill and tap. duct tap the T-stat hole, to keep out the chips.
you might have had bolts to long, and they bottomed out, and are frozen on the threads.
is your manifold aluminum ?
grind the bolts off flat and square, use a center punch and dimple a center spot.
start with a small bit, and drill your pilot hole straight and square in the center of the bolt.
if you go off center, you will just hog out the aluminum around the bolt.
slowly working up to the size hole and tap you need.
Don't drill thru the bottom of the bolt holes.
All of this is much harder on the car, but do able, go buy some new drill bits.
Straight and square pilot hole... right thru the bolt center,
Don't drill thru the blind hole in the manifold. (Not to Deep)
your gonna have to drill and tap. duct tap the T-stat hole, to keep out the chips.
you might have had bolts to long, and they bottomed out, and are frozen on the threads.
is your manifold aluminum ?
grind the bolts off flat and square, use a center punch and dimple a center spot.
start with a small bit, and drill your pilot hole straight and square in the center of the bolt.
if you go off center, you will just hog out the aluminum around the bolt.
slowly working up to the size hole and tap you need.
Don't drill thru the bottom of the bolt holes.
All of this is much harder on the car, but do able, go buy some new drill bits.
Straight and square pilot hole... right thru the bolt center,
Don't drill thru the blind hole in the manifold. (Not to Deep)
Burning Brakes
Joined: Nov 2006
Posts: 893
Likes: 7
From: Orange Park Florida
Go to sears and buy the nut style bolt removers. The nut slides down over the broken bolt, and when rotating it in the counter-clockwise direction it will snag the bolt and back it out. First though, soak the bolts with pb blaster, or any good penetrating oil..
good luck!
good luck!
Le Mans Master
Joined: Dec 2006
Posts: 5,557
Likes: 9
From: Oquirrh Mountains
St. Jude Donor '09
Do none of the above. Doing this by hand will will likely end up ruining your manifold.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Intermediate
Joined: Feb 2012
Posts: 28
Likes: 0
Kroil and Heat are your friends...
Just my opinion, but after trying other penetrating oils, including PB Blaster, I have found that Kroil does the best job. The aerosol version of Kroil is AeroKroil. Google on "Kano Labs", buy direct. Expensive, but worth every penny. Let it sit overnight, or even two days with reapplication.
As expressed above, heat is your friend. Welding the nuts on is the best bet. Without access to a welder, the nut style extractors may work with heat applied to the manifold. Even with welding on the nuts, gently heating the manifold with a torch right before attempting to back out the studs will expand the female hole, and loosen the grip on the studs. You will have to drain the AF before you apply heat.
As expressed above, heat is your friend. Welding the nuts on is the best bet. Without access to a welder, the nut style extractors may work with heat applied to the manifold. Even with welding on the nuts, gently heating the manifold with a torch right before attempting to back out the studs will expand the female hole, and loosen the grip on the studs. You will have to drain the AF before you apply heat.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Do none of the above. Doing this by hand will will likely end up ruining your manifold.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Drilling this out in the car is going to just make a mess and screw up the manifold for sure.
If you don't have a welder, then just pull the intak and take it to a shop...or take the opportunity for an intake upgrade
Drifting
Joined: Aug 2005
Posts: 1,372
Likes: 4
From: Springfield VA
Does not look there is enough to install 2 bolts, good idea if there was though.
I would try a extractor. Drill the center of the bolt and try an extractor. If that does not work then drill and tap.
I would try a extractor. Drill the center of the bolt and try an extractor. If that does not work then drill and tap.
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Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
you're going to have to drill those puppies out. as mentioned, cover the coolant hole. then grind the top of the bolts flat. then use a dremmel like bit to make a center dimple. if you aren't exactly in the center, regrind the top flat (it helps to visualize the entire bolt so you can see the center)and try again. then use a small bit (1/8") and make your first cut the entire length of the bolt. i like the home depot brand bits (rigid) at slow speed, firm pressure and lots of oil. then increase to the size bit needed to retap the hole(i think it's a 3/8 so you need 21/64"). then just retap. don't rush!!!! the manifold metal is softer than the bolt steel, and if you drift off-center you're screwed. i've drilled out more of these rusted bolts than i care to think about, and the only time i have problems is when i rush the job. you'll be surprised how quickly a sharp bit will cut thru the bolt.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
Do none of the above. Doing this by hand will will likely end up ruining your manifold.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Get two. Nuts and place them over the existing broken stubs. Weld them to the studs. Allow them to cool. Apply a good rust penetrant and let it soak for a day. The heat from welding and the lube should allow them to break free.
Just break out the welder and weld it up!
Not everybody has a welder or can weld, so now what?
All that would do is break the bolt off at the bottom of the first nut anyways.
The PB blaster is the only hope, otherwise its tap and die.
I would put a set of vise grips on them and work them back and forth and that might work also after the pb blaster.
Last edited by Tim H; Apr 12, 2012 at 08:49 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Looks like an aluminum manifold and steel bolts. When dissimilar metals are 'engaged' some galvanic action is created between them and corrosion is the next step. They will almost weld together, as a result...very difficult to get them to separate well.
When you get the bolt stubs out (and you will, I'm sure), make sure you use some anti-sieze on the bolts/studs you reinstall. Also, you will need to reduce the applied torque, as the anti-sieze will act as a lubricant. Use the torque spec. for lubricated threads (usually about 60% of 'dry' install torque value).
Good luck.
When you get the bolt stubs out (and you will, I'm sure), make sure you use some anti-sieze on the bolts/studs you reinstall. Also, you will need to reduce the applied torque, as the anti-sieze will act as a lubricant. Use the torque spec. for lubricated threads (usually about 60% of 'dry' install torque value).
Good luck.
Thread Starter
Racer
Joined: Feb 2012
Posts: 390
Likes: 1
From: Livonia MI
I drained the Antifreeze and the bolts are soaking in PB blaster this evening. Tomorrow I'll heat the manifold around the bolts with my MAP gas torch and try the nut type bolt removers. I figure if they don't work, I can always drill a hole in the bolts and use the extractors that you insert into the hole. If that fails, I'll use the grind, drill and tap method.
This should be interesting.
Thanks for all the info.
This should be interesting.
Thanks for all the info.
Le Mans Master
Joined: Oct 2010
Posts: 6,930
Likes: 845
From: melbourne florida
2023 C3 of the Year Finalist - Modified
here's an off the wall one. get a stud pliers heat up the stud and melt candle wax on it. it actually worked on one for me another time not so much. if you take it off I'd get a different manifold.
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
I drained the Antifreeze and the bolts are soaking in PB blaster this evening. Tomorrow I'll heat the manifold around the bolts with my MAP gas torch and try the nut type bolt removers. I figure if they don't work, I can always drill a hole in the bolts and use the extractors that you insert into the hole. If that fails, I'll use the grind, drill and tap method.
This should be interesting.
Thanks for all the info.
This should be interesting.
Thanks for all the info.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
So far im with timH, its amazing how strong a nice set of vice grips can grab a thread. Use the penetrating oil of your choice and give it a go next day.
If that fails i would have a go at drilling but like most have said with the manifold off. Drill to deep with that manifold on the car and some metal shavings fall through it could mean GOODNIGHT for that motor.
I would think about a new manifold as well.
If that fails i would have a go at drilling but like most have said with the manifold off. Drill to deep with that manifold on the car and some metal shavings fall through it could mean GOODNIGHT for that motor.
I would think about a new manifold as well.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Do what you can with it on the engine. When you need to get more aggressive, you can remove it to limit risk to the engine. If it gets the best of you, then you can take it to a machine shop for repair, or just buy another manifold, if that will be less expense.
If you are patient, I think you can fix it on the car.
If you are patient, I think you can fix it on the car.
Racer
Joined: Nov 2008
Posts: 293
Likes: 1
From: Eaton Ohio
I would cover the hole well, plugged with a cloth and covered with tape. Apply PB blaster a few time over a 24hr period, try out some vice grips and then if that doesn't work get an easy out bit. You have to drill a shallow pilot hole then use the easy out bit.
Drifting
Joined: Jul 2008
Posts: 1,873
Likes: 27
From: Sonora CA
Please be careful of the gas in carb. It's not the gas, it's the fumes that ignite. If it was me, I would just remove the carb. and distrib. And take the manifold off. Then you can have all the access you need to remove those bolts, then you can paint the whole manifold if need be. Or just go ahead and by a new one. But be carful of the fumes and a flame.!
