Tom in Austin

I've been pretty lucky with bolts on mine, but something I do now religiously is clean up the holes with a thread chaser before putting the bolts back in. Got a set on Amazon for like $20 ...

namasgt

Just drill them out starting with a small drill bit. I recommend using reverse drill bits you can buy them from sears it takes about 2 to 3 days to get them. Worst case you have to use helicoil repair which is not a big deal. I think you can do more harm to the block trying to undo the broken bolts out of their holes. Be careful when you drill. Use medium to slow speed and don't put too much pressure, You don't want the drill bit to go trough the block.... Then you will be really screwed.

Mrmerlin

when you go to refit the bolts use good quality carbon steel bolts not SS
use anti seize on the threads.

One thing to consider when using heat on the block or the heads is that,
since the surface is aluminum it transfers heat very quickly,
thus the water in the block also absorbs heat very quickly,
thus the best way to remove stuck bolts if your using heat is to drain the block first.

since you already have the bolt loose,
I would drain the block soak the bolt shank with PB or Aeroqroil and then heat the area a few times to let it soak in,
then try the heat it, soak it,

a few times about 2 hours later then,

heat the area around the bolt and screw it in a few turns then soak it then unscrew it after you have heated the area around the bolt

G8RB8

Lots of guys once they get a fastener turning just keep going no matter what. That bolt is partially out, so lube it up and run it back in, then back it out till it gets tight again. Repeat until it's out.

U-928

This.

If you can get a slightly larger torx head bit hammered in there, you'll be able to loosen and tighten the stripped allen. The easy-out ones rob posted wont let you turn in the tighten direction. +1 on the ATF acetone mix. Stuff is a miracle liquid.

17prospective buyer

Break the head off, lift off the part, then weld a nut to the remaining bolt shank.

ChuckD

After some heat and more PB blaster soaking, I finally got it out without breaking it. It worked only if I tried immediately after heating. Anyone know what that brown crap might have been if it only responded to heat? Threads in head look fine. This is all due to some divine intervention, I think. One of my favorite tools that was my Dad's was a giant screwdriver with a square shaft. It allowed me to use my largest adjustable wrench on it and turn this f#%&ing bolt out. Thanks for the ideas. So glad it didn't snap or wreck the threads in the head.

ChuckD

forgot to attach the picture

SeanR

I have to say Matt, you are pretty smucking fart. For a youngin your advice isn't too far off at all and most of what you say makes sense.

Thanks and glad you are here.

Chuck, good job on that. I typically end up cutting the head off because I lack patience most days.

Mrmerlin

what your looking at is steel corrosion mixed in with some block material be generous with the antiseize.
BTW did you drain the block ?

928 at last

Does this mean I should bring my impact driver?????

928 at last

And a torch??

Ethre

Easiest way to bath the underbody in oil - break one of the contact tips off the oil pressure sender. Then drive down the highway and let it do its magic.

jon928se

Since nobody else has responded to your very valid question my thoughts

If it's a steel bolt in an Alu block not in contact with oil but water in this case, See if you can get some Duralac Zinc Chromate paste. Best bet is to try a marine chandlers or marine engineers supply kind of place. Its not available everywhere as the solvent in the paste is MEK but for dissimilar metals in contact with water it is the only answer. Navy and Air Force types may know it colloquially as Yak **** or Chicken **** due to its colour but believe me it is the business. Doesnt play too well with oils.

Mike Frye

Chuck, glad you got it out!

Yeah the biggest problem with the stuck bolts is the dissimilar metals thing. Over time it forms something close to JB weld in there I think.

+1 on chasing EVERY bolt before reassembly, and I am a firm believer (convert?) in antiseize.

I never had a set of bolt chasers, but Adam and I made a set when we did our last top end refresh by just cutting two grooves in one of each size bolt we removed 180 degrees off (water pump, water bridge, intake, fuel rails) after cleaning them up with a wire brush. We also had to blow out those water bridge holes because there was gunk down in there that a chaser would never get out.

It becomes a Zen thing when you take a Q-tip to your engine to try to get every last bit of grime or gunk out of there. That's part of the reason I got this car.

Zen and the Art of 928 Maintenance.