Broken Valve cover bolt

[YukonGold12]

Welp, a two hour job just got longer. I noticed my valve covers were leaking oil on the 202k 07 Yukon. Figured I would replace them.

Got everything in and good but the last bolt feels like it snapped on me.. I was using the torque wrench too..

Video below of what it looks like now. I think I’m going to need to take it to a shop, is this drivable or is it better to tow? The closest shop is about 25 miles away.

 

[alvocado]

Pull the bolt. You'll know when you back the bolt out if it broke or if you have a stripped hole. Assuming it broke, pull the cover and see if there's a bolt stud that can be extracted. You might have enough sticking out to grab with a vice grip.

 

[Joseph Garcia]

^^^^^x2^^^^^ You may get lucky and be able to extract the bolt yourself.

 

[YukonGold12]

I pulled the bolt this morning. It’s not broken, but stripped. The bolt is intact

 

[YukonGold12]

Bolt image

 

[Joseph Garcia]

Bolt image

I recommend that you get a tap thread chaser for the specific bolt thread and carefully clean out the socket hole, WITHOUT allowing any shavings to fall into the motor. This will ensure that your replacement bolt screws in cleanly. You don't HAVE to do this, but I would.

 

[mikez71]

Sounds like helicoil time.
It must have been previously stripped...

 

[alvocado]

Agree with chasing the bolt hole and trying a new bolt.

You should pull the cover to chase the hole and use a chase, not a tap. You can probably find a single chase in the right size if you don't have or want to buy a full set but t hey are worth every penny if you make the investment.

 

[j91z28d1]

that bolt looks like it bottomed out or something.

did you happen to torque them to ftlb instead of in lb? it's happened before.

 

[Doubeleive]

I would just drop a new bolt in there, torque to spec and send it, there is no way any minute shred of anything is going to work it's way out of a threaded bolt hole and into the engine, if for some reason that thread hole goes all the way thru the head then any shred of metal has already dropped in, in that case change the oil and pray.

 

[Dustin Jackson]

Confession time: 3 years ago when I did the AFM delete on my Tahoe I stripped one of the valve cover bolts out. I just moved on to the next one and never looked back. 30K miles no problems, not saying this is good advice but you get to set your own risk tolerance.

 

[YukonGold12]

that bolt looks like it bottomed out or something.

did you happen to torque them to ftlb instead of in lb? it's happened before.

Nope, it was in/lbs. I was using my small torque wrench that only does in/lbs.

 

[YukonGold12]

I would just drop a new bolt in there, torque to spec and send it, there is no way any minute shred of anything is going to work it's way out of a threaded bolt hole and into the engine, if for some reason that thread hole goes all the way thru the head then any shred of metal has already dropped in, in that case change the oil and pray.

So you don’t think I should chase it? Just pickup a new bolt and try it?

 

[Doubeleive]

So you don’t think I should chase it? Just pickup a new bolt and try it?

Try it before you put the cover back on

 

[Geotrash]

So you don’t think I should chase it? Just pickup a new bolt and try it?

That's what I would do also, but keep in mind that the threads are cut into aluminum and that's a steel bolt so the threads in the hole are already compromised. I give it one chance in 5 of holding enough torque to seal the valve cover. A helicoil will take you 20 minutes to drill, cut the threads for it, and set the helicoil itself in place. Easy peasy - so much so I don't even think about it anymore if I come across stripped threads. I just go ahead and put one in. I have a whole set for any metric sizes and thread pitches I'm likely to run into.

 

[YukonGold12]

Ok here is what I’ve done so far.

I pulled it apart and chose a different bolt from a different hole. I hand tightened then turned not even a quarter turn to snug. It’s not loose at all.

I ran a chaser through the hole just to check and there was no resistance.

I then put back the original bolt without the cover on and it’s also tight… so now I’m wondering what even happened..

New bolts get here tomorrow.

 

[alvocado]

Any chance the bolt was slightly misaligned when assembling and it missed the hole? It looked like it wasn't catching any threads the way it was spinning in your first video.

Regardless, take the win and be relieved you aren't looking at a bigger repair. Sometimes you get lucky!

 

[Doubeleive]

The "stipping" would be at upper end of the bolt (making it just spin), this bolt if it had fully entered the hole would have held perfectly fine
unless there was something at the bottom of the hole it would have just stopped and not been fully seated, maybe a burr or some other foreign material.
so @YukonGold12 was it just spinning loose or was it not able to be tightened anymore?
looks to me like the tip got messed up, maybe it was sitting angled on the outside of the thread hole? if this was the case there may have been some evidence around the thread hole tower.

 

[YukonGold12]

unless there was something at the bottom of the hole it would have just stopped and not been fully seated, maybe a burr or some other foreign material.

Great question, I had checked the hole when I took the cover off, and it looked clear. My theory is the same as yours that it just missed the hole.

It wasn't spinning loose entirely, I could feel resistance, but it gave way when I was tightening it, which made me believe I stripped it.

 

[j91z28d1]

did you happen to get a pic of the threads in the hole?