I've been trying to replace the head gaskets on my 97 xk8 (see my other picture post of the R/R https://www.jaguarforums.com/forum/x...ctures-198595/) and the head bolt just snapped off in the block!

I was making the initial pass of 15ft/lbs and the bolt broke off but the torque wrench never clicked! It's the first time I've used the torque wrench in a while and I'm wondering if maybe it was not working and I over-tightened the bolt?

I believe its safe to say my engine is ruined. I can't imagine how I can extract a bolt so deeply embedded in the block or thread another bolt into the broken bolt. I think its fate telling me to dump this never ending repair job on a beautiful car.

 

WELL.

Step 1. grab adult beverage of your choice (unless you already have)
Step 2. take a deeeeeeeeep breath
Step 3. realize it can be removed and may actually not even be tight in the threads

I am guessing a long metal tube the size of the thread hole with a long drill bit inside it would be a good start followed by an easy out with a long extension. Your engine is definitely not ruined and you WILL get the small bit out and have a happy ending- just don't rush it and think it through. Likely you hit some liquid at the bottom 1/4 of the threads and it snapped there.

 

I have had the same thing happen in a 4.0 AJ6 engine when I re-used a head bolt as per the Jaguar recommendation.

I torqued the bolt and then performed the 'torque-to-yield' rotation when it 'snapped'.

I spayed some solvent into the hole and blew it dry.
I applied a dab of 'two-part' epoxy to the end of the bolt and re-inserted it into the hole to feel for the mating surfaces to lock together.

I let the epoxy setup overnight and gently removed the broken end in the morning!!!!!

New head bolt installed and finished the repair!!!!!!!!!!!!

bob

 

Thanks very much for the advice and info! The bolt broke because I think I over tightened it. I'm hoping the 2 part epoxy is strong enough to undo the bolt. Will any epoxy suffice? Should I try JB Weld ? What about stud mounted on top of the broken bit and capped off with a nut?




Size difference

 

First of many adult beverages on the way....

I thought I did a thorough job of blowing out the holes of any moisture. I think my torque wrench might be malfunctioning?
I'll be doing my research because I'm sure I'm not the first to f-up like this. Thanks for the advice and adult beverage encouragement

 

If you don't feel comfortable doing the extraction take it to a machine shop preferably an automobile engine machine shop. Believe me they have seen this before.

 

to reiterate what others have said and add, sometimes a professional should be called as you might not make it better but could make it worse.

 

Would leave it to a professional as well, but here is an interesting way as well :

 

Looks crazy but it might work.

 

I'd exhaust the more traditional methods first , if it's not bottomed it may come out easily.

 

It's now probably best to replace the remaining bolts as well.

Thoroughly clean and dry all head bolt threads and holes in the block.

Obtain a better torque wrench before attempting again.

 

Those more knowing than me can correct me, but I don't think the bolts can "bottom" out with the head installed. Definitely agree though to replacing bolts with all new. (LS bolts are less $$ FYI)

 

Bumping for update?

 

Waiting for the bolt extraction tool kit to arrive......

 

I might be missing something, but wouldn't it be easier to remove the broken head bolt with the head off. I can't tell by the photos but if the bolt broke in the head and not in the block you might be able to remove it with vise grips.

 

Bob is right- for SURE you are going to want to remove and replace the head gasket.

 

I was finally able to remove the bolt from the block! Now back to the project at hand! Thanks for the advice and help from the forum

 

BUT HOW?

 

I'd guess at Bob's solution from post#2?

 

I used a bolt extractor kit I found on Amazon. The tricky part was getting to the bolt as it was about 2+ inches below the deck surface. Center punched the bolt then used a small section of plastic tubing around the drill bit to keep it as centered as possible. Frequent checking with the boroscope and compressed air to keep it clear. Once I got about 3/4 inch deep I tapped the extractor (barely rising above the block deck!), once secure it came out like butter.

Now waiting for the metal head gaskets to arrive to (finally) finish the project.