Broken Vanos Mounting Bolt

[E11even]

Well..need some help.

Was just finishing up my complete Vanos upgrade and broke the left Vanos mounting bolt (10mm socket). The bolt is a Kx2 8.8, it’s one the the two partially threaded bolts for mounting the Vanos. Anyone know the part number? Having trouble finding a replacement.

The bigger problem is gonna be getting the broken end out of the cam side of the block. Feel like an idiot, was torquing to spec with new oil line mount seemed to cause the issue. Any ideas other than an ez-out or drill?

[karter16]

You mean #11 (07119904589) in this (https://www.realoem.com/bmw/enUS/sho...diagId=11_2994) diagram?

[E11even]

Yes. #11

[karter16]

https://www.fcpeuro.com/products/bmw-hex-bolt-with-washer-m6x35u18-8-07119904589

[E11even]

Thanks. It’s strange that the part is a partially threaded screw but this part number shows a fully threaded. Is the because of an updated part? Or doesn’t make a difference either way?

[jet_dogg]

Well..need some help.

Was just finishing up my complete Vanos upgrade and broke the left Vanos mounting bolt (10mm socket). The bolt is a Kx2 8.8, it’s one the the two partially threaded bolts for mounting the Vanos. Anyone know the part number? Having trouble finding a replacement.

The bigger problem is gonna be getting the broken end out of the cam side of the block. Feel like an idiot, was torquing to spec with new oil line mount seemed to cause the issue. Any ideas other than an ez-out or drill?

Probably best to center punch, left hand drill bit and some type of extractor.

[karter16]

Thanks. It’s strange that the part is a partially threaded screw but this part number shows a fully threaded. Is the because of an updated part? Or doesn’t make a difference either way?

The original part was 07119901973 which was superseded by 07119904589 from mid-2007, so that would possibly explain it. Secondly it's entirely possible that FCPEuro's photo is not correct.

[sapote]

Thanks. It’s strange that the part is a partially threaded screw but this part number shows a fully threaded. Is the because of an updated part? Or doesn’t make a difference either way?

No reason it should have full threads but it's doesn't matter.
You're lucky it didn't strip the threads in the head. The remain broken bolt protruding or inside the threaded hole? If it's slightly protruding, then cut a slot on its end, then use the impact driver and hammer to turn it CCW back out just like a screw.

[E11even]

Broke inside the threaded hole. Spent the last two hours punching drilling and trying to extract the remaining screw tip. Couldn’t get it to back out even with the extractor getting good bite. Had to drill out the the screw, definitely screwed up the threads in the block.

Will try to re-install tomorrow when new bolts arrive. Got a bad feeling… may have to try to re-tap some in the block. Any thoughts of the screw won’t thread?

[George Hill]

Use the vanos unit as a drill guide, timesert, reinstall dowel and bobs your uncle.

[Cubieman]

If the threads are messed up really you are only left with the options of maybe finding a close sized US standard pitch bolt that fits as to not have mess with the hole size on the vanos itself and re-tap once the old screw is out OR use a helicoil/time sert.

A helicoil should work just fine if properly installed, also maybe you can get lucky and use a thread chaser and/or tap to recover your mangled threads. In any event its definitely fixable, just take a to a shop if you don't feel comfortable doing a helicoil.

Edit: As George said above a timesert may be the way to go.

[E11even]

Yeah this has turned into a disaster. Literally snapped the bolt on reinstall was so close to being done.

I was able to drill/retapp with the alignment dowel in place as a guide. Screw threads pretty well. Now the dowel is damaged. Are these essential for install? Guess I got order.

[sapote]

1. Screw threads pretty well.
2. Now the dowel is damaged. Are these essential for install? Guess I got order.

1. what does this mean? Oh, messed up the threads.
2. Don't need the dowel if you can center the vanos pump disk to the hub driving tangs.

[heinzboehmer]

2. Don't need the dowel if you can center the vanos pump disk to the hub driving tangs.

Well, the dowel also helps align the surfaces on the head and vanos so that the valve cover gasket seals correctly. Personally, I would (and did) put it back on after a thread repair.

OP, I'd do what George Hill said. Timesert is doable without removing anything, you just need a right angle drill or to do it by hand. They also sell drill guides if you don't want to be taking the vanos on and off a bunch. Dowel will need to be trimmed slightly lengthwise, but that's about it.

[Slideways]

Yeah this has turned into a disaster. Literally snapped the bolt on reinstall was so close to being done.

I was able to drill/retapp with the alignment dowel in place as a guide. Screw threads pretty well. Now the dowel is damaged. Are these essential for install? Guess I got order.

It's only a dollar and worth having to align the VANOS perfectly to the cylinder head.

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