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8mm broken studs wont comne out

jerry

jerry

Old Git
Joined
May 12, 2006
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Cricklade
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Multiple Monsters
Not Ducati but an engineering problem on my Fiat engine ,, replacing EGR its a well known issue that the 8mm bolts rust in place ,, 2 came out after lots of heat and pentrating oil and torgue hammer but 2 sheared with about 8mm clear ,, so More heat , more penetrating oils 3 days now ,, then Snapon gripping Stud extractor but still not budging they are totally rusted in over 200fy lb of torque used !!!!!

cant use 2 nut trick not enough thread above engine block and I cant weld to save my life ,, even if I had a welder.

its clear to me that the penetrating oil is not penetrating at all any ideas guys

drilling them out might be next option ????????? if I can get a drill in the space ???
 
Ally block ,,, I managed to drill one of them out yesterday and re tap it ,, gonna try the other one today ,, this one will be much more difficult due to access

The 2 that i got out with extractor were rusted on every thread ,,,and still are even with huge amounts of penetrating oil and heat ,

my mechanic mate says sometimes to do this job on fiats the engine has to come out !!!!!
 
I recently had the same thing on a Land Rover transfer box - 2 of the 6 x M8 bolts on the cover plate were seized and snapped pretty much flush to the ally casing, certainly too close to get any grips on.

I didn't want to try drilling as that could knacker the ally rather than the bolt and then there's the risk of any stud extractor or drill breaking inside, making the problem worse because it's now hardened steel in there.

Using a mig welder, I placed a nut over the top of the broken bolt and, on full power filled the hollow with weld, meaning I now had a nut on the end of the broken stud to get a socket onto and that, combined with the extreme heat from the welding broke them free.

The reason I asked re. ally or steel is that the above is more complicated on a steel block as you risk welding the nut to the block whereas mig welding steel won't stick to ally.

I know you said you don't have a welder but, someone local must have a portable rig they could bring over - got to be easier than taking the engine to someone.

It works well and quick and not likely to damage the block, I'd happily pop over and do it for you if you were local.
 
Sadly the last bolt does not have enough to weld a nut onto my mechanic mate looked , he has welding gear so drilling is only option and yes some ally will be damaged but I have 8mm helicoils so some wiggle room , here hoping

Im not rushing this
 
Should still work even if the top of the bolt is below the surface as you fill the hole with weld. Of course it might not take and could break off again but that'll only leave you back where you started having lost nothing but potentially saved a lot of hassle.

Either way, good luck with it.
 
And the heat generated by the welding exercise will probably help in freeing the remains of the bolt….
 
My mechanic mate came back with an induction coil unit , we moved the radiator to get some more clearance ,,, heated the area up to almost red hot and cooled it with penetrating oil tried the welder and a nut did not help ,, we then drilled a hole and are tried an eziout but its not shifting it , we are having a cuppa and will probably drill it all out like the first one
 
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OK TOTAL SUCCESS The bolts are all out ''HOORAY''

Drilled a pilot hole 3mm in last bolt but had to shift radiator to get more access,,, even so the pilot went a little off center , drilled it to bottom then used a 5mm drill ,,, then used a super hard titanium dremel router bit in my drill and rounded it all up ,soaked it again in oil had a cold beers then put 6.5mm drill down hole and on reverse all the remaining thread came out , threads are rusty but have cleaned it all up so now all 4 of 8mm holes are ready for the next step which is fit the throttle actuator but i will use copperslip and torque it all to 30ft lb
 
Nice one and a good call on the copperslip, if Fiat had done that you may not have had all this bother...
 
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