Snapped Intake Bolt

[CmansX]

Good morning everybody. I am in the process of completing a Valley Pan gasket change. Following the DIY, I was torquing the bolts to 21lbs on my M62. One of the bolts snapped.

How much trouble am I in? Should I just slit my wrists now? Is there a remedy?

Thanks for any input.

[TwinTurboGTR]

Hey CmansX.

I am assuming you used my DIY on the VPG. The proceedure should be updated on the page in the notes section as other members that have done the DIY have also snapped bolts at 21ft/lbs. I did this job 3 times and at 21 lbs, I have not snapped one bolt. But I believe as a precaution, I noted that the bolts should be tightened hand tight then a 1/4 turn of the wrench, approx giving 13-16/ft/lbs. As for the snapped bolt... its a stud. I believe you can just back the stud out and insert a new one in. Doing one, should't disturb the head mounted to the block. But 2 or more on the same side will. In that case, all will need to be backed out and then retorqued down in an X pattern.

[TiAgX5]

Progressive torquing is ALWAYS a good idea, takes longer but reduces risk of fastener failure. Finger tight, 50% final torque, 80% then 100%. Always a cross pattern from the center out.

[upallnight]

Are these bolts one time use bolts? Some bolts are meant to be used only one time since torquing them stretches the bolt and reusing them is not advised

[TiAgX5]

These are not TTY (torque to yield) fasteners/studs.

[racingbmwm3]

Never heard of these ones breaking before, I've broken a few of the valve cover studs on a variety of engines though. My recommendation when working on small fasteners like engine parts, the smallest tool that can get the job done helps prevent breaks. And non-torque critical fasteners, I agree with TwinTurboGTR, hand tight plus a little is fine. Always torque in stages to prevent misalignment issues, especially when installing wheels, and don't torque under load.

single use 'bolts' are generally only found in critical areas (prone to high loads and/or vibration, as in the headbolts, crank bolts/flywheel, and a couple of suspension bolts. If you ever see a torque angle specified in the instructions, that needs to be a new bolt**
Typically, the only fasteners that are recommended for regular replacing/one time use are the self-locking nuts (nylock or jetnut)

**not really, but unless you are a material science engineer and willing to run the calculations to determine the new torque angle for a previously stretched/yielded bolt, it's safer to just replace it.

[CmansX]

Thanks for the input. I was able to order some from the local dealer. I freaked at first but thankfully its not going to be that bad.

Is the 21 lbs correct? I read in another post it should be 11 lbs. That seemed to make more sense.

[racingbmwm3]

do like it says in posts #2 and #3.

[TiAgX5]

Intake to head fasteners are to be torqued to 11 ft/lbs.

When torque is that low I always use an in/lb tq wrench, and go slightly below (130 inch/lbs).

[upallnight]

Originally Posted by TiAgX5

Intake to head fasteners are to be torqued to 11 ft/lbs.

When torque is that low I always use an in/lb tq wrench, and go slightly below (130 inch/lbs).

No wonder you're snapping bolts if you are torquing them to 21 ft lb.

Someone must have confused NM with ft.lb. when they posted 21 ft.lb. instead of 20 nm.