Hi guys,
When it rains it pours.

I was changing the valve cover gasket on my 2003 XJ8 (driver's side) and while tightening all the bolts to 9-11nm using the torque wrench, it snapped the bolt (not sure why, whether the bolt or torque wrench issue but I would think it's the torque wrench).

I had a guy come over to help me extract the screw (marked as #1 on the attached image) and while he was drilling to use the screw extractor, his tiny drill (1/16) snapped and we don't know where it is, possible went inside (marked as #2 on the attached image).

What do I do? I think this will be the end of my DIY car projects

1. Would it be ok to put everything back and just not use bolt #2 as presented on the attached sheet from the manual book?
2. What if the little drill bit (1/16 by probably 1inch) is actually there? I have no idea of what may happen. I don't want to find out that my car gets on fire or something....

 

If you have not put it back together, go to your local part supply or tool store and buy a mechanics magnet with a long, telescoping extension and reach into each of the galleries until you engage the broken drill bit. Likelihood is your buddy has one in his tool box since he has extractors (he has made this error before. . . as we all have).

 

The openings are really tiny, and I don't know if it's even there.

I think you are referring to something like .

Thank you for your reply. Are you able to answer my other questions?

 

I've broken one of those before, but I was able to get a hold of it with some needle-nose pliers and twist it out. I would not do anything else until finding that broken piece of drill bit. It could be under the cam shaft; if you have a small magnet-on-a-stick, fish around under there and see if anything comes out. Or, you can pull the exhaust cam to look underneath. If you go that route, rotate the engine clockwise until the cam flats are up, then zip tie the chain to the sprocket through one of the holes in the sprocket. It's easier if you remove the tensioner, but probably not necessary to just take a look under the cam. After removing the caps, you'll have to lift the cam shaft up until the lobes clear the lower half of the bearing or race, then tilt the back up until you can see underneath it. When you're done, lay the cam back in and tighten the caps to 10nm. If the piece of drill bit isn't there, I would check the sump. I'm not certain, but most engines drain the oil backdown to the sump, so it might have fallen down there.

Good luck !!!

 

use a reverse bit next time

 

Thank you. I'm 100% sure that this is well beyond my abilities. :-/

 

I have even had to make my own 'flexible' extension magnet by soldering a telescoping magnet 'head' (just the magnet) onto a length of solid copper wire so it would bend around corners.

I added it to my 'magnet-collection' for finding things like broken bits.

 

I purchased the magnet stick (small 0.25inch) and tried my best fishing it, but no luck. As I said, I don't even know it's there. Any advice?

 

Well, that's a hard one ....
I personally should loose sleep if I knew it still might be there, even if it did not show up yet.

What I should do is some more fishing attempts, possibly over some days (I had cases where things which did not work at all at the first attempt, then went smooth a day later).

If nothing shows up from the fishing, I should indeed lift the cam.
It's not a whole lot of work, and if you are careful on installation (without inducing stress on the camshaft), it's not difficult.

All this to be absolutely sure there is nothing floating around, cause if it is, it will surely create way bigger problems sooner or later.

About the snapped bolt, that location provides pressure on the spark plug seals.
As they are prone to leak over time anyway, I don't think you can do without a bolt there.
Should however not be too difficult to extract for someone who knows what he is doing.

 

You need an endoscope to take a look down the hole.

 

Fishing around, nothing found, close it up and drive it. Probably sitting under the manifold or on the fenders or on the ground. If it is inside, it will work its way to the sump and be dumped at the next oil change. Appreciating Eric's concern, maybe an oil change is in order . . .