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Yesterday while we were trying to change the thermostat on a Buick 3.8L V6 MPI disaster struck – one of the two bolts holding the thermostat housing broke in the aluminium base.
Now there’s a little bit left of it left above the surface (5 mm). Can you please advise on what’s the best on-site method for getting it out – we don’t have access to a welder where this happened?
For the future – is there any way to prevent this from happening when working with corroded-in bolts and bits?
Many thanks!
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To prevent this.use anti seize on the bolts.to extract the remaining
bolt.you could slot the top and try a screw driver to turn it out.
you could try a small chisel or punch to try and turn it.soak it with
penetrating oil.you could try heating the broken bolt then try tapping
it with a hammer to loosen the corrosion. then try to back it out after
it cools.You could also drill straight down through the center and try using an EZ-Out bit to remove. Be CAREFUL not to break the EZ-out or you will have even more problems. I have drilled bolts and used a progessively larger bit until I could collapse the bolt or get it to loosen. Worse case scenario if you mees up the threads you can install a helicoil. Plenty of anti-seize on the new bolt!
How you treat it depends on how you broke it. If it was while you were removing the bolt, that means the bolt was seized to the block (unless you were turning it in the wrong direction). If you overtightened the bolt you should be able to get it out easily with vice grips. Assuming the former, soak it good with penetrating oil then use an “Easy Out” after drilling a hole in the bolt (take your time and use a center punch). Worst case you will have to replace the intake.
If you break the “Easy Out” off in the bolt you are done.
You said it has some of it protruding still, thats a good thing. Really a shame you don’t have a welder, that makes life very easy. What I would do is cut a slot in the top of the screw. Get an impact driver with the flat bit. Heat the housing where the bolt threads are with a propane torch good an hot. You really need to get this baby hot enough because if you wreck that little bit sticking up you’ll be drilling it out. Once it is up to temp hit the impact driver and use the Divine Method of bolt removal (pray like hell the little bastard doesn’t stick in there). If all goes well you’re looking at a clean empty hole. If not you need to mark it with a starter punch in exactly dead center and drill it with a left twist drill bit. Then heat again with the torch and try backing it out with an EZOut. If it feels like the EZOut is going to break, stop right there and back the tool out. You’ll be pulling that intake out if you break the little devil off in there. You won’t find a drill bit that can drill the steel extractors are made of. At that point, you’re going to be drilling out the whole screw and putting a Heli-Coil in. Thats where making sure you have been drilling dead center of the broken bolt makes the big difference. If the bit gets a chance to go off center it will walk off the bolt and go for the manifold, since the aluminum is easier cutting than steel.
Good luck with this one. By the way, Irwin makes a pretty damn good extractor kit. It has the socket-style extractors for broken off pipe thread fittings, the EZOuts for broken bolts and a set of left-twist drill bits. The price isnt bad for the quality of the tooling. A HF extractor breaks off too easy and then you’re in for hell. I use a set of Matco extractors and I would say the Irwin ones are at the same caliber of steel quality.
I live in the rustbelt, so I never get vehicles that are unsalted. Broken bolts are a daily thing. If I didn’t have a welder I’d try what I suggested as I’ve had a lot of success with that method. After all, I didn’t always have a welder.
If you have enough bolt sticking out a spiral type damaged bolt extractor may work. I have a craftsman set that has served me well. another trick for loosening the stuck bolt is to heat the bolt then apply some candle wax ( parafin wax ) to the heated bolt. the wax is drawn into the threads and loosens it up. I have never personaly tried this but have read posts from others that swear it works.
I had something happen exactly like this. I have 3 bolts on my housing and I broke two of the three. If you break the heads clean off what I did it knock the the housing off with a rubber mallet. After it comes off i could see the two bolts. I then hit it will some PB blaster and some heat then just took a pair of vice grips and turned it out. It kind of took a while but its way better than trying to drill out really small bolts. You will have to go but a replacement bolt. Just take the bolt with you and get the same length and size. It will be pretty cheap.
I broke off a few on a honda. I just mark dead center on the bolt with a center punch and then drill it out using larger and larger bits till it collapses or I can pull it out with vice grips. Luckily I haven’t had to tap anything doing this and had good luck on not mucking up the threads. Many times a small hole drilled in the middle of it is enough to break the tension on the bolt and allow for easy removal.
PB Blaster is your friend. Before I touch any bolts, I spray it down and let it soak and spray it again.
A study did find that ATF and Acetone mixed works great as well.
http://www.practicalmachinist.com/vb/general/ot-penetrating-oil-196347/
Problem solved with a lot of heat (propane torch), WD-40, patience and a few heart-felt prayers.
Now comes in handy all the advice about preventing this sort of agony from repeating itself.
Thank you all for the useful ideas and support in handling this issue!
P.S. I’m starting to hate engines with steel and aluminum parts bolted together.
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