Crushing discovery - head is cracked.

[Pablo M]

I. Am. Beside. Myself. 
A crushing discovery today. Sorting out the oil leak issue I had, suspecting it from the distributor o-ring or dist bracket bolts I came to discover the head is cracked below the distributor housing. Impossible to see from below or above. Only by using a mirror and light did I discover it. Took me hours. 
This is the head I just had rebuilt last October. Months to get it back in and get the car running.  It didn’t leak like this before. My first thought was I over tightened the head bolts. Crack is on the head bolt sleeve. But I checked old photos and crack was there when I picked up the head. 
I just got to enjoy the car for the first time only these last few weeks. I’m really just beside myself, completely defeated. 
 

This photo is at idle, oil pouring out of the crack. 

 

This, in my trunk when I picked it up. 

 

How does this happen? How does the machine shop not see this? I didn’t notice it on pick up and it sure didn’t leak like this before. 
I know the right fix is a replacement head, or pulling this one and having it welded (and rebuilt again after?) but I’m thinking of cleaning and drying it then JB weld repair. 
Honestly, this has put me in a dark place.  

[NickVyse]

Guess it was missed as it's such an unusal spot to crack. But, personally, given your situation, I agree and would dremel it out a bit, clean clean clean and give JB Weld a go. What's the worst that could happen?

 

Is it the casting for one of the head bolts? May be it was previously torqued down with oil in the bore.

Edited May 11 by NickVyse

[tzei]

I had such a leak nearly same place. Since head was due to be worked i had it welded.

[Dudeland]

So sorry to hear of the crack.  It truly sucks.  That is a bad one and there is one permanent fix, which is to take it off and get it welded.  The good news is that you won’t likely need to get any additional work done. 
 

I am about to spin my car over for the first time .  I imagine I will be in the same camp as you when I find out something is toast that puts me back a month. 
 

Let us know how it goes. 

[JWT]

I am with others....clean clean clean and give JB weld a shot.  However, I also agree that the only fix is to weld it up properly.  Rest assured, I know it is tough for you right now, I have been in the same place more than once.  If the JB weld holds or slows down the leak at least get some enjoyment out of it and then, the time will come (usually sooner than you think) thatreally its not such a huge job.  Commit to a day to get it done and just motor through it.  $hit happens.  We all miss things. We human. 

[kbmb02]

Ouch - that bites. To date I’ve only seen one other M10 head with a crack in the head-bolt boss (one of the inner bolts) - I had it welded and machined* while having the head work done. (*if/when you do this, obviously make sure the bolt fits through the hole after welding). 

 

In the meantime, I’d agree with others and try the JB weld (not the 5 minute version, but the long-cure type - IIRC, the long-cure is for higher temp applications). Good luck. -KB

[Stevenc22]

Im with everyone else. Clean and JB weld for now. Likely it will hold for years. After a few years of driving you will likely need to pull the engine or head for something else and then you can fix it right.

[TobyB]

That's a really odd place to crack...  

 

If'n it was mine, I'd pull it now, and get your machine shop to fix it.

If they're any good, they'll feel bad about missing it, apologise,

and not charge you much to weld it up and sleeve it.  

 

I had a similar experience with corrosion through a bolt hole- the head was 

a bit questionable, and when I took it back to the machinist I really liked,

he bored out the bolt hole and pressed in a sleeve.  That was 25 years ago, and 

I'm still waiting for it to leak again.

 

t

 

[JQ02]

So sorry to hear! I have a couple 121 heads, but would be total restart and I’m on the east coast. 
Hopefully you can fix it!

[Gordon]

Welcome to the cracked head club.  In 40 + years of 02 ownership, I've been there twice, Yes it sucks but you'll make it better second time around.

 

Just remember to take your front timing chain cover to the machine shop with you. My (former) mechanic forgot to do that and I had oil leak issues upon getting my new head back from the machine shop. 

[Pablo M]

Thanks everyone. Glad to hear that the JB Weld isn’t considered a ghetto fix. I know removing the head and having it welded is the proper fix, but I can’t contemplate taking it back out again after just putting it in. I’m sure it would go in and out very quickly this time, but I just can’t wrap my head around it. 
Im going to try to do the JB Weld repair with head in place, removing the distributor flange and valve cover to gain better access. 
I’ll try to get it fixed before next weeks SoCalVintage Twisties and Tacos event next Sunday. 
 

[Pablo M]

9 hours ago, kbmb02 said:

In the meantime, I’d agree with others and try the JB weld (not the 5 minute version, but the long-cure type - IIRC, the long-cure is for higher temp applications). Good luck. -KB

I just bought some for a different project. Says it’s their strongest, and it’s the original. I assume this is what you’re talking about. 
 

[JWT]

dooooooooooo ittttttttttttt..............

[Stevenc22]

Yes, the original is perfect!

[Son of Marty]

Clean the crack out with brake clean a couple of times then work the JB weld into the crack with a tooth pick and let it set up for 24 hours or so.

Edited May 12 by Son of Marty