It is common I have found to struggle with the removal of two particular head bolts. Left side, #4 and 5 from the front. Coolant seems to get there and rust them into place.

So the recent engine (N42/N42) needed the head off, and sure enough, all were easy to break free, but #4 was a struggle, and #5 broke. Here we go again.

Took the head off, and found stage one of the birthday present. The bolt broke a good 3/8” of and inch above the block! Yahoo!

Look at the crud around that bolt. The head gasket was mostly eaten through here. Old engine, old coolant.

So I wire brushed the stub clean and set up a rag pad around it to hold penetrating oil and let her sit for 24 hours with hourly application of more weasel squeezings....

 

And today, the final stage of my birthday present, I was able to put a vise grip on the stub and easily break it free then unthread it by hand. Yahoo! 

It never goes this smooth....

What do you think? Buy new head bolts or just re-use the old ones? 

Edited May 23, 20213 yr by zKars

Nah chuck it and use a nice big wood screw!

Just fill the hole in the block with JB weld.

There's no way I would reuse that bolt.

I would chuck up the remains of the bolt in the lathe and drill a hole in the end. Do the same thing to the threaded stump, and then turn a metal dowel pin to fit the holes. Press the dowel pin into place to align the two while you run a small weld bead around where it broke. If your welding skills are good, they say "the weld is stronger than the base metal".

1 hour ago, Captain Obvious said:

There's no way I would reuse that bolt.

I would chuck up the remains of the bolt in the lathe and drill a hole in the end. Do the same thing to the threaded stump, and then turn a metal dowel pin to fit the holes. Press the dowel pin into place to align the two while you run a small weld bead around where it broke. If your welding skills are good, they say "the weld is stronger than the base metal".

I’m totally doing this! New bolts are a fortune! Thanks!

if you really need a bolt ill send you some.....

10 hours ago, zKars said:

I’m totally doing this! New bolts are a fortune! Thanks!

Just trying to do my part.

For solidarity, I got lucky too. Did a happy dance:

zKars,  You would need to hold a gun to my head in order for me to reuse any of those old head bolts.  Bite the bullet and get a fresh, new set.  They won't break most banks. They are about a hundred bucks for a set of OEM bolts!

Interesting.  I've had good luck removing frozen fasteners with vise-grips over the years.  My theory is that it comes from the shock created when the pliers -- adjusted to a strong over-centre setting -- are clamped closed.  You can almost hear the pliers ring when they go over-centre and lock.  No penetrating oil required.

2 hours ago, mayolives said:

zKars,  You would need to hold a gun to my head in order for me to reuse any of those old head bolts.  Bite the bullet and get a fresh, new set.  They won't break most banks. They are about a hundred bucks for a set of OEM bolts!

Entire thread is tongue in cheek I assure you. I cannot always be counted on to do the right thing, but in this case, I know what to do. And in this case it involves charging my customer a nice markup for new bolts.

Edited May 24, 20213 yr by zKars