RESOLVED - Stripped out the cylinder head bolt hole while replacing valve cover, what now?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

bdbull

Full Access Member
Joined
Dec 27, 2016
Posts
163
Reaction score
109
Murphy's law strikes again.

Was out doing the valve cover replacement on my 2010 Avalanche. Job is a breeze. Putting the new valve cover on and the two middle bolts literally stripped the threads out of the cylinder head. WTF?!?! How in the world does that happen? When I took the cover back off, both bolts had the threads on the bolt. I had to unscrew the threads from the freaking bolt.

So, WTF am I supposed to do now? I figure I have two options.
A. Put the valve cover on with the two outside bolts and whatever threads the middle bolts will grab. Drive the truck down to my local shop (about 4 miles) and let them sort it out.

B. Order a helicoil kit and try to fix it myself.

I'm leaning towards A just because I'm so pissed that this happened, and I just don't want to deal with it. There's no telling what else I might destroy while I'm in there.

Anybody ever done something like this or am I the only idiot that the universe has decided to shit on this way?
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
21,296
Reaction score
30,248
Location
Treasure Coast, Florida
Murphy's law strikes again.

Was out doing the valve cover replacement on my 2010 Avalanche. Job is a breeze. Putting the new valve cover on and the two middle bolts literally stripped the threads out of the cylinder head. WTF?!?! How in the world does that happen? When I took the cover back off, both bolts had the threads on the bolt. I had to unscrew the threads from the freaking bolt.

So, WTF am I supposed to do now? I figure I have two options.
A. Put the valve cover on with the two outside bolts and whatever threads the middle bolts will grab. Drive the truck down to my local shop (about 4 miles) and let them sort it out.

B. Order a helicoil kit and try to fix it myself.

I'm leaning towards A just because I'm so pissed that this happened, and I just don't want to deal with it. There's no telling what else I might destroy while I'm in there.

Anybody ever done something like this or am I the only idiot that the universe has decided to shit on this way?
Let them put heli coils in it if they are competent or do it yourself after you take a break!

Haven't stripped a valve cover thread but have messed up plenty of other things, used to have a whole set of heli coils! LOL
 
OP
OP
bdbull

bdbull

Full Access Member
Joined
Dec 27, 2016
Posts
163
Reaction score
109
Well, I just took it up to the shop. I'll drop by there tomorrow morning after I drop my son off at school (in his car) and tell them what happened. I'm hoping it will be something simple for them to do.

I've never done a heli coil before, and at this point I just don't feel like learning something new...and possibly screwing that up too. Maybe another day. In fact, I need to change the oil in my wife's Tahoe but I'm gonna wait until I get my truck back just in case I find a way to screw up an oil change.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
21,296
Reaction score
30,248
Location
Treasure Coast, Florida
Well, I just took it up to the shop. I'll drop by there tomorrow morning after I drop my son off at school (in his car) and tell them what happened. I'm hoping it will be something simple for them to do.

I've never done a heli coil before, and at this point I just don't feel like learning something new...and possibly screwing that up too. Maybe another day. In fact, I need to change the oil in my wife's Tahoe but I'm gonna wait until I get my truck back just in case I find a way to screw up an oil change.
Good call, I've had days like that too.
 

George B

¯\_(ツ)_/¯
Joined
Feb 5, 2020
Posts
7,882
Reaction score
18,994
Location
Oconomowoc, Wisconsin 53066
This is the kind of crap that happens to me a simple job gies sideways. Ugh!

I realize the truck is i. To have this fixed but for the sake of conversation I have a thought.

Sometimes In situations like this I got lucky and there were threads remaining further down the hole that a longer bolt would grab.

Good luck with putting coils in. I know that is a solid fix in this case.
 
Last edited:

Fless

Staff member
Moderator
Joined
Apr 2, 2017
Posts
16,319
Reaction score
33,746
Location
People's Republic of Colorado
You guys who have done multiple helicoils -- are you in the habit of using (red?) loctite on them when you install them, or something else, or leave them dry? I did one on a lawn mower exhaust bolt thread, so not a helicoil virgin, but not an expert...
 

George B

¯\_(ツ)_/¯
Joined
Feb 5, 2020
Posts
7,882
Reaction score
18,994
Location
Oconomowoc, Wisconsin 53066
You guys who have done multiple helicoils -- are you in the habit of using (red?) loctite on them when you install them, or something else, or leave them dry? I did one on a lawn mower exhaust bolt thread, so not a helicoil virgin, but not an expert...
Here is some info I found.
 

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
7,845
Reaction score
20,403
Location
Richmond, VA
You guys who have done multiple helicoils -- are you in the habit of using (red?) loctite on them when you install them, or something else, or leave them dry? I did one on a lawn mower exhaust bolt thread, so not a helicoil virgin, but not an expert...
I use blue Loctite on anything I may need to remove, including bolts installed into helicoil threads.

Super important to use a torque wrench when working with aluminum especially. I have to relearn the lesson every few years the hard way. The good news is I’ve gotten really good at doing helicoils. @bdbull once you do one you’ll wonder why you ever felt intimidated by it. I did and I was the first tIke.
 
OP
OP
bdbull

bdbull

Full Access Member
Joined
Dec 27, 2016
Posts
163
Reaction score
109
I use blue Loctite on anything I may need to remove, including bolts installed into helicoil threads.

Super important to use a torque wrench when working with aluminum especially. I have to relearn the lesson every few years the hard way. The good news is I’ve gotten really good at doing helicoils. @bdbull once you do one you’ll wonder why you ever felt intimidated by it. I did and I was the first tIke.
I think that's why I was so damn mad. I was using the torque wrench and sat there thinking, "good grief, is this every gonna torque down?" Then I realized something was wrong.

I kinda wish I would have at least attempted the heli coil, but having to drill out the hole just scared the hell out of me. Hopefully they'll be able to get it done without too much trouble, otherwise I will be giving it a go. :)
 

tom3

Full Access Member
Joined
Jul 15, 2019
Posts
1,411
Reaction score
2,467
I've had some luck over the years with using a stud instead of a bolt. Bottom out the stud in whatever threads are left, then put a nut on it. A stud is a whole lot better as it is not turning while being torqued.
 
OP
OP
bdbull

bdbull

Full Access Member
Joined
Dec 27, 2016
Posts
163
Reaction score
109
Got my truck back yesterday. Cost me $300 for them to do the heli coil kit and an oil change bc they got metal shavings in it when drilling it out. I'll probably run it for a few hundred miles and then change the oil again just to be safe and get it back to what I like to run on it.

I probably could have done it myself, but whatever, it's done. As my dad used to say, "it's just money, i'll make more tomorrow."
 

drakon543

Full Access Member
Joined
Feb 15, 2016
Posts
2,473
Reaction score
1,722
most helicoil kits are designed to have a bite after they are actually inserted. there's a few different versions from a typical spring style look to a full thread insert. i have never used any type of loctite on a helicoil as the normal type has a chance of the loctite getting on the inside and causing you an issue reinstalling the bolt. the thread insert style has tabs you use thier special tool or a hammer and a punch to push into the metal to lock them in place. drilling in a sensitive area as inside the head like that should be drilled slow with a second person with a shopvac sucking the drillings up as the come off. you can also use a clear cup of some kind and drill through cup into the piece to contain the shavings if your by yourself. if your drilling steel in a sensitive spot i use the same thing with magnets glued inside the plastic cup. working facyory maintenance for a while now myself and you have to be the shop and come up with some nifty home made accessories.
 

thompsoj22

Full Access Member
Joined
Jul 21, 2018
Posts
689
Reaction score
718
Location
california native "REPUBLICAN" high desert
I think that's why I was so damn mad. I was using the torque wrench and sat there thinking, "good grief, is this every gonna torque down?" Then I realized something was wrong.

I kinda wish I would have at least attempted the heli coil, but having to drill out the hole just scared the hell out of me. Hopefully they'll be able to get it done without too much trouble, otherwise I will be giving it a go. :)
quite likely the mech before you? they knew the next guy was hosed and your up! helicoil is simple, youll be driving for less than a Benjamin!
 

Just Fishing

Can't fix stupid
Joined
Aug 30, 2020
Posts
4,499
Reaction score
10,114
Location
Utah
You guys who have done multiple helicoils -- are you in the habit of using (red?) loctite on them when you install them, or something else, or leave them dry? I did one on a lawn mower exhaust bolt thread, so not a helicoil virgin, but not an expert...

I took a crash course with helicoils in my vette.
I suppose the rear ends cover either had never been off before, or the last time it was off the threads were damaged.

Either way, no matter how hard and how careful i was, the threads would not allow me to torque to the proper spec, and i had never ending leaks.

Compounded by the fact that the diff cover is a structural part of the suspension.
It also serves as the transmission mount... lol

I ended up having to go with helicoils to fix it.

The helicoils have a little part at the rear that bites into the aluminum once fully installed.

But i did use red loctite for the install.
Careful to not get that red loctite on the inside of the coils.
I did not want any chance of those coils backing out for any reason.

After 24hrs, i installed the rear cover with blue loctite.

They are not too hard, but doing it again i would suggest to do it on a test piece first.
After two of them, the install made more sense to me.
 

petethepug

Michael
Joined
May 4, 2016
Posts
3,788
Reaction score
4,356
Location
SoCal
Nope, you did the right thing. Once you get the damage done and you’ve got that feeling of “can’t undo this”, it’s a good idea to call in a pro. What if you really did run into someone else’s f up timed to go off when you touched it. Handing it off to a pro made have saved you from an advanced level fix beyond the norm.

I had to rebuild the same motor three times because my pop overlooked the cylinder taper wear. He lost $400 on new pistons. Next we got a reman block that had a stripped head bolt discovered AFTER the block was installed.

After doing it again we got another reman block that had a camouflaged repair on the same head bolt. The company broke the corner of the block off and used brazing rod to build it back up and some how tap threads to spec. The corner of the block fell off when torquing it down. The piece that broke off was all brazing half the size of a slice of bread.

My pop was cheap but with good intentions. People often pulled the wool over his eyes. He wasn’t upset I had done the job three times at 17 years of age, he was embarrassed and angry he got swindled. The Reman company installed the 3rd motor at no charge.

My pop lost weeks of time, I paid time to gain experience. If you haven’t done a job that requires a fix to an overhaul job gone sideways, team up w/ a pro or let the job out. Kudos to you for doing the smart thing. Who knows what else the shop ran into on the repair. If it fails again this year, guess who’s NOT doing it over again.
 
OP
OP
bdbull

bdbull

Full Access Member
Joined
Dec 27, 2016
Posts
163
Reaction score
109
Doing some more work and one of the other bolt holes stripped out so I guess I'll get my chance to learn now to do it. I've been doing some research and people seem to like Timeserts or Keenserts more than Helicoils.
 

Forum statistics

Threads
137,745
Posts
1,991,110
Members
102,735
Latest member
Jumpshot12
Back
Top