Put the morning aside to change cam cover gasket. Putting it back on i set torque wrench to 22NM and guess what POP !! bolt 1 sheared. Im guessing the wrench is faulty (or i may have cocked up somewhere)
To say im fed up is an understatement. A tiny bit of the screw is visible in the housing.
How can i get it out and will i have casued any damage to the bolt housing ?
You need to get a stud extractor, drill a hole in the screw wind in the stud extractor (left hand thread)and the old bolt will wind out, thread should be ok as the bolt broke 
Ive thought about a stud extractor but concerned as bolt is very narrow diameter, and also waste getting into the cam area. It may be an option though. Would the trapped piece be under high tension ? Should i try and grab the 3 mil that produding, what about cutting a groove for a screw driver ?
Im so Pis**d off !
Give it a try and also use a small punch to possibly get it started.
I’m not 100% sure that not using a bolt in there will be a problem.
If it felt like it sheared quite easily it’s likely that it will tap out with a pin punch, I’ve never found “easy outs” to be particularly effective, which is what’s described above, most sets I’ve used have been cast and break quite easily, especially small ones, a punch usually does the job, but after that my preferred method is to fit a nut over the protruding bit of bolt and weld it to it, the heat on it’s own generally frees off a stuck nut, but if not you have a solid anchor to use a socket on.
When you get it out, remember to set your torque wrench to no more than 8.8NM. 22NM is way too high. Most torque wrenches don’t go down that low.
Thanks for replies. Bit confused over torque setting. Ive read 22nm and 43-78 foot pounds. My torque wrench starts at 28 Nm so i turned it back 6 notches for 22. How can you torque accurately so low ? It did feel like it was being overtightened but i had faith in the wrench and recommended setting. I Should have stopped i know!!
The bolt was bottom centre (No 1), can you really get away with not having a bolt in here without leaks ?
How does it tap out with a pin punch. Its trapped in the threaded part of the housing ? Sorry im a bit new to car DIY
Ive just noticed that its 43 to 78 inch pounds not foot pounds !! This is a nightmare. 8Nm is about right as mentioned above. I guess i will have to buy s smaller torque wrench ?
Just tap the protruding part of the bolt anti clockwise at it’s edge with a thin pin punch and a hammer, if it was going in OK when it sheared it should shock free, then when it’s loose enough get a pair of grips on it and spin it out.
Yep, I have just a torque wrench for this one job. You don’t really need it. The bolts are barely finger tight.
IIRC they are 22lbs/ft
Take the cover back off and you will proably have enough stud to get grips on
With the cover off there maybe just enough to get a set of mole grips on it and out, in all the years i have been doing this my advice on tightening these bolts up is NEVER use a torque wrench, tighten them all up (11 ) in the correct order and nip them up, thats all they need, the number of times i have seen snapped rocker cover bolts snapped from owner useing a torque wrench on them is unbeleiveable.
Shout if you need me buddy.
M-m
As im missing a bolt could i run the car with one missing and fit this later, or will this ruin the gasket shape ?
I sheared a bolt, one at the back of the engine. I meant to sort it but being busy at the time didn’t get round to it. As it hasn’t leaked since, now almost 12 months, I have left it. Not best engineering practice but I am happy to leave it unless it leaks again.
Personally i would get it sorted as soon as you can, but she should be ok just for the time being, i would not leave it for to long a length of time like the above ,there are 11 bolts for a reason buddy.
M-m
There is always the other option drill a 4 mm hole and screw in a large self tapping screw with a washer, It will tighten it down for now and you can use a stud extractor when you get one and some time… Its not pretty but It may work for the time being 
you can put rags around the hole to catch the swarf then just wipe it away then what I do is use a old speaker to make sure (the bolts steal so the magnet will pick up the bits)
Got the bolt out with pliers, just! Refitted with an M6 bolt from local DIY shop. Ran for 20 mins, so far so good. Will check in a couple of hours for a little pool of oil, (but hopefully not.)
No such thing as a straight forward job! I was going to do the CAS o ring but decided against it. At least the cam belt looks in good order.
Cheers Folks.
Think you might mean 22 lbs/in, 22 pounds hanging on a 1 foot lever may end up shearing a few more?