Broken valve cover bolt n52k
 

Welp. My torque wrench must have failed me, or I got a seriously defective bolt with my new VC.

On the plus side it’s in a fairly easy place to work. On the bad side, it’s seriously in there. I managed to get the valve cover back off and put some vice grips on it. They won’t turn it at all. Not sure if it’s friction locked at the bottom or if I cross threaded it? Not sure how that would have happened as it went in without resistance.

Either way it is seriously in there & I’m a bit lost as to what my best option is.

It’s the third or fourth bolt back from the front of the engine on the intake side.

What’s my best course of action? Left handed drill bit? Bolt extractor? I’m kind of at a loss because I was expecting the vice grips to just twist it right out.

Here’s a photo

https://i.imgur.com/EjMuWPw_d.jpg?ma...idelity=medium

My N52 came with a leaking valve cover due to 2 pre-broken bolts. Easy to remove with a left handed bit. I had a bolt extractor on hand as well but did not need it. The aluminum bolts drill through extremely easily.

This is the updated plastic cover with steel bolts. Same methods?

Nope. Mine is the magnesium cover with aluminum bolts. Yours will be more difficult. Though I would think the left handed drill bits and an extractor would still do the job.

Any reason I shouldn’t just pull the fuel rail off so I can get vice grips on it at a proper 90 degree angle? I’m thinking it would turn out if I wasn’t fighting the lateral play in the grips when grabbing it too down at 180 degrees.

or just clamp hard with a vicegrips going straight in- then use a wrench on the VG right at the head where it clamps the (now) stud?


Can you go back and forth? Turn in a few turns, then back out..then in... does it get easier, maybe let the threads 'unbind'?

I would avoid removing the injectors, but you can try removing the rail itself. I don't see any penetrating oil on the bolts in the pics. Throw some at the base of the bolts.

It’s out! Honestly it wasn’t too bad. I pulled the fuel rail & injectors this morning. They were pretty fouled anyways so I gave them a cleaning.

Once the fuel rail was out I had nice 90 degree access to the bolt. I had hoped my vice grips would bite and just turn it out but the fine teeth are pretty much wore out.

I taped everything off surgeon style by cutting a slit in some masking tape and putting the bolt through it, then taped a trash bag to that to cover the inside of the head.

I took a small file and gave each side 10 min or so with the file to get a flat surface to grip. Viola! Vice grips turned it right out and I was able to finger it out as soon as it unbound.

As I was working with the file I regularly used a neobydium(sp) magnet to pull metal shavings from the area.

All in, once I had a fresh mind & calm hands it only took about 20 min to get out. Could have been much worse.

I’m pretty sure my torque wrench failed me as I was at the lower end of the limits, but either way a steel bolt for sure shouldn’t have snapped. I work with my hands for a living and I wasn’t cranking it hard. I’m going to reuse the old bolts for reassembly.

Kinda sucks I have to wait for BMW to open their parts department tomorrow. I’m for sure going to replace these injector o rings.