[StradaRedlands]

The new car has a snapped head bolt (I know it's not really a head bolt). According to PO it's been that way for nine years now, and is the source for a pretty constant oil leak. It's just slightly loose, but I can't get it to spin with a pick tool. I'm thinking pull the manifold and try a left-hand drill bit to back it out? Other suggestions? Does it seem like a DIY job, or should I take it in to a shop? Thank you BMW experts!!!

Click on the image, and it's a short video on Flickr:

E90 headbolt valve train bolt broken

[mainbearing]

Pelican Parts suggests removing the intake manifold out of the way, then just use a pick to spin it out. See first picture in the link below. Then there are others under the valve cover that should be inspected.

Otherwise for the external one at least, I guess a small drill in the center into this aluminum bolt, then with a left-handed extractor to spin it out if a pick does not do it.

https://www.pelicanparts.com/BMW/tec...J52wLrC4bBF47t

[StradaRedlands]

Originally Posted by mainbearing

Pelican Parts suggests removing the intake manifold out of the way, then just use a pick to spin it out. See first picture in the link below. Then there are others under the valve cover that should be inspected.

Otherwise for the external one at least, I guess a small drill in the center into this aluminum bolt, then with a left-handed extractor to spin it out if a pick does not do it.

https://www.pelicanparts.com/BMW/tec...J52wLrC4bBF47t

I'm going to have to commit and do it! I'm just not so good with drilling or anything delicate. What could possibly go wrong!?!?!?!

[lowrydr310]

Before you go drilling, try spraying some Kroil in there and let it soak a bit. If you don't have that, PB Blaster should work well too.

I had the same bolt broken on my 330i for who knows how long and I was able to easily get it out with a pick. Two more bolts under the cam sprockets also have snapped heads but I'm not pulling cams to fix that. There's no oil leaking, I'm guessing because the two big bolts on the ends are still good for now.

[Efthreeoh]

Originally Posted by StradaRedlands

I'm going to have to commit and do it! I'm just not so God with drilling or anything delicate. What could possibly go wrong!?!?!?!

Use a machinist's center punch to dimple the bolt shaft so the drill bit doesn't walk on you. Run the drill slowly at start with good pressure on the bit so it cuts into the aluminum. Then use a left-hand extraction tool.

[lowrydr310]

Originally Posted by Efthreeoh

Use a machinist's center punch to dimple the bolt shaft so the drill bit doesn't walk on you. Run the drill slowly at start with good pressure on the bit so it cuts into the aluminum. Then use a left-hand extraction tool.

Better yet just try a left handed drill bit, McMaster sells them individually for just a few bucks.

[NZE90]

I did this job on my car 3 days ago. I removed the airbox, unbolted the manifold from the cylinder head and pulled it back enough to access the bolt with a drill.

I used a LH drill bit in the hope the bolt would unwind itself while i was drilling a hole in it for the bolt extractor. No such luck!! The bolt was tight as fuck! So i then put a bolt extractor into the hole i had just drilled in the bolt. It wouldn't budge and felt like the extractor was going to break. Took the extractor out, got a punch and gave the bolt a couple of good smacks with a hammer, put the extractor back in and it came loose!

Torque spec for the new bolt is 15nm + 90° for N52 and
10nm + 90° for N52k

[Tambohamilton]

Can't spin it with 1 pick? Try 2 picks? Serious suggestion. Probably binds when you push it with a pick, but being able to counter that with another pick may yield results? Bit of penetrating lube shouldn't hurt either...

[StradaRedlands]

Originally Posted by Tambohamilton

Can't spin it with 1 pick? Try 2 picks? Serious suggestion. Probably binds when you push it with a pick, but being able to counter that with another pick may yield results? Bit of penetrating lube shouldn't hurt either...

Thanks for the advice, appreciated! I did try using two picks, just not in that little video. Wouldn't budge. The access was really tight, so I'll try again after pulling the OFH. That'll give me a lot more clearance before resorting to pulling the manifold and drilling. I flowed a little PB Blaster down on it as well. I think I'll eventually get it, and hopefully the "easy" way without drilling!!! I have the new bolts ordered (Rein vs BMW, as the BMW ones are stupid-expensive).

[Tambohamilton]

Sounds good. Good luck!

[Cloverdale]

Repeated lubrication / liquid penetration might be the difference. Heat applied to the surrounding area might also be beneficial.

[StradaRedlands]

I'm going to start off with the two pick process and if that doesn't work move on to left hand drill and possibly an extractor. Either way I'm going to need to move the OFH and manifold. I've never needed to do a manifold yet, but it looks relatively straightforward. Can probably just pull it off of the studs to get enough clearance, but I might actually pull the whole thing and clean up the half court oil sitting in the gully by the starter!

[smass]

Originally Posted by StradaRedlands

I'm going to start off with the two pick process and if that doesn't work move on to left hand drill and possibly an extractor. Either way I'm going to need to move the OFH and manifold. I've never needed to do a manifold yet, but it looks relatively straightforward. Can probably just pull it off of the studs to get enough clearance, but I might actually pull the whole thing and clean up the half court oil sitting in the gully by the starter!

Yes you can pull the manifold front edge forward a few inches to gain access. This saves a lot of time compared to removing the manifold. I have done a few of these and they come out easily once they start spinning. The oil leak keeps them from getting tight.

[NZE90]

Originally Posted by StradaRedlands

I'm going to start off with the two pick process and if that doesn't work move on to left hand drill and possibly an extractor. Either way I'm going to need to move the OFH and manifold. I've never needed to do a manifold yet, but it looks relatively straightforward. Can probably just pull it off of the studs to get enough clearance, but I might actually pull the whole thing and clean up the half court oil sitting in the gully by the starter!

I just pulled mine off the studs as you suggest, it worked fine but i must admit i was a bit nervous about my lower PCV hose. I also changed my inner DISA while i was in there, as it was seized.

I forgot to mention that i blocked my inlet ports off with tape. Once you start drilling the aluminium swarf flies around a fair bit.

[NZE90]

Not sure which N52 your car has StradaRedlands but i just noticed that the N52K engine has a different torque spec to the early N52. Early N52 is 15nm + 90° N52K is a slightly lower 10nm +90°

[StradaRedlands]

Originally Posted by smass

Yes you can pull the manifold front edge forward a few inches to gain access. This saves a lot of time compared to removing the manifold. I have done a few of these and they come out easily once they start spinning. The oil leak keeps them from getting tight.

Originally Posted by NZE90

I just pulled mine off the studs as you suggest, it worked fine but i must admit i was a bit nervous about my lower PCV hose. I also changed my inner DISA while i was in there, as it was seized.

I forgot to mention that i blocked my inlet ports off with tape. Once you start drilling the aluminium swarf flies around a fair bit.

This makes sense, thanks for the confirmation! I bought some new gaskets as the 18 year old ones on there could probably use a refresh!

Originally Posted by NZE90

Not sure which N52 your car has StradaRedlands but i just noticed that the N52K engine has a different torque spec to the early N52. Early N52 is 15nm + 90° N52K is a slightly lower 10nm +90°

Ohhhh, thank you for confirming that! It's a N52K based on what Bimmer.work is telling me. I would not want to break the new one!!!

I will report back with my findings... one way or another, this is going to get fixed!

[StradaRedlands]

Hey everyone, THANK YOU for motivating me to do this. I was getting ready to pay someone to do this job, but y'all convinced me to try it. I pulled the intake aside which is easy (I've never done it so was a little worried, but literally NBD) and the OFH (which I've done five times or so). I punched a little dimple in the middle and one offset to the side (it was sloppy). Sprayed some more PB on it, and started with the picks. It took a good 45 min or so, taking breaks, but seeing it slowly spin made my day! I'm leaving the manifold off as I want to replace the breather hose when I do the valve cover never week. Plus I want to get some of the oil out that's all over the cavity area by the starter.

THANKS again for the wisdom and encouragement!!!



Here's a good little video from Tim Zeiten that shows the process:

https://youtube.com/shorts/8tILM6-HLuM?feature=share

[StradaRedlands]

New bolt from FCP (Rein not BMW, $7 vs $90). The threads in the head are pretty contaminated with oil, but no way to really clean them. 10Nm + 90^ and we're good to go!!!
Now on to pretty much every other thing you can replace on the car!!!