GM LS Broken Exhaust Manifold Bolt Fix (step by step with pics)"

[GASoline71]

A lot of you already know the thread I had earlier about a busted exhaust manifold bolt on the 6.0L in my 2006 Chevy K2500HD. After more research and finding that this is a very common problem with not only the 6.0L, but all 3rd gen LS based engines in trucks.

So I decided to start a thread that detailed how I fixed this broken bolt. Of course it was the rear bolt by the firewall on the drivers side. Hard to get to. But after some discussion with people here, and my brother in law (mechanic), I went for it.

I have a welder and could have went straight for that option. But since most cats don't have access to a welder, I decided to try drilling the bolt and then using an "EZ-out" type extractor. However... in the end, the welder was what I used. You'll see why. There is very little room to maneuver, so this fix did take me all day long.

Anyways... here goes...

Pic #1, The culprit. Pic taken from underneath the truck.

Pic #2, Collector nuts. These were a Biotch. I soaked them with penetrating oil for 2 days. They were still tough to get off. An impact didn't even budge them. So I next used a breaker bar on them, and I was pulling so hard, I was actually bending the breaker bar! They finally came loose. I got lucky and didn't bust a stud. You'll need a 15mm 6 point deep socket.

Pic #3, Remove the wheel and tire to get more room, and remove inner fender.

Pics #4 and #5, The clips that hold the inner fender. There are 8 clips you pry the center section out with a flat screwdriver. Then there are 2 clips that pull straight out. The clips that pull straight out I used a pair of straight nip thingy-ma-dealios. Just grab behind the flat part to the shank of the clip and pull. Then the inner fender falls right out.

[GASoline71]

Pic #1, Manifold still in. With spark plugs and wires removed.

Pic #2, Manifold out. Pretty straight forward removal. It will come out through the top. Be very careful not to bang the manifold on the coil packs as you wiggle it out of there. The posts that the wires slip on hang a little in the way... so use caution.

Pic #3, Looking through when the inner fender as still on.

Pic #4, Pic looking through with inner fender out.

Pic #5, Close up of the broken bolt in the hole.

[GASoline71]

Pic #1, The extractors I used.

Pic #2, The extractors have a cutter on one end. I actually used a left hand drill bit before this, but forgot to take pics. I had to cut the drill bit down to get enough room to drill. Then used the cutter to make the hole big enough for the extractor.

Pic #3, Hole drilled.

Pic #4, the extractor in the hole, and starting to attempt to turn it out.

Pic #5, End result...lots of cussing.

[GASoline71]

Pic #1, Break out the Lincoln 140C

Pic #2, There is a perfect spot on the block right below the head to put the welder ground on. I used a small angle grinder to take off the rust. Remember to unhook the negative terminal on your battery before starting to weld.

Pic #3, Thick washer that was a tad smaller than the hole, and a nut. I penetrated the washer perfect on the first try. However, I used 3 different nuts because due to the angle you have to weld at, it was hard to get penetration on the inside the nut. So I finally used a bit bigger nut and gave a good hot tack on the outside of the nut to the washer. Also the first 2 nuts, I didn't have the heat up enough. The bigger nut, I turned he heat up all the way, and had the wire speed on 5. In hindsight... the wire speed could have went to 6.

Pic #4, Washer held on with duct tape. No rom to hold it with a gloved hand. Be quick to blow out any burning tape. It WILL catch fire... trust me. But it's not a huge fire. Just be aware that you have to blow out the fire. I had a compressed air hose at hand with a nozzle.

Pic #5, First attempt at welding the nut. Held nut with tape too. This nut spun off when I put a socket on it.

[GASoline71]

Pic #1, This was the 3rd attempt, and the one I got to stick. I had to grind off a little of the weld on the outside of the nut to get the socket on.

Pic #2, SUCCESS!!! Since these bolts are "glued in" (prolly Loc-tite) from the factory... the heat from the weld loosened it up, and it came out EZPZ!

Pic #3, The hole with no busted bolt in it!

No need to show putting things back together with new bolts and gaskets. If you got this far... I'm sure you can get it all back together.

Hope this helps anybody that has to do this fix. It's a PITA, but doable. Bottom line is... use a welder on the first attempt. You WILL break off an easy out in the broken bolt, since they are glued in from the factory.

Good luck!

Gary

[GASoline71]

I forgot to mention, and have no pics of it. There is a small heat shield low on the firewall, that is held on by three nuts on studs. Remove the nuts, and remove the shield. It will gain you another inch or more of space by the bolt hole. Trust me... you need all the room you can gain!

The wire I happened to have in the welder is Lincoln .025 solid wire. I also have 25/75 shielding gas. Not sure how this would have worked with a cheaper no-gas welder using flux core wire. With my welder, and the gas... there were virtually no sparks, and no slag. Just wanted to make note of that.

Gary

[prostreetC-10]

We often use heat to loosen up stuck bolts/things. What's nice about using the welder is that it not only attaches the nut but also super heats the broken stud so it's easier to get out. I stripped the allen drain plugs that were in my block. I welded a smaller bolt on to each one and they backed right how.

Nice job Gary. I'd almost swear you must live in Oregon after a move like that! lol

[GASoline71]

Thanks fellers...

Us Rust-heads up here could show you Oregon boys a trick or 2!

Gary

[rfmaster]

Nice write-up GAS! Sounds like another good reason to get MIG/TIG

//RF

[GASoline71]

A follow up... I pulled my 30ft 5th wheel over to Eastern WA an back over the weekend. It pulled 2 mountain passes in 90 degree heat and did just fine. I hope the new bolts and gaskets hold up for at least anothe 100,000 miles.

Funnly thing though... a lot of Chevy/GMC trucks of the same generation in the RV park we were in with 6.0L engines... most of them with exhaust ticks just like I had when started up cold iron. Once the engine would warm up and everything would swell... tick goes away.

Gary

[Russell]

Almost every single LS powered truck I've encountered has this issue. Definitely a design flaw on GM's part... I need to fix the manifolds in my 03 Tahoe sometime as well. Same issue.

Welding a nut onto the broken bolt is definitely the best way to get these out. Well done!

[storm9c1]

Originally Posted by GASoline71

A follow up... I pulled my 30ft 5th wheel over to Eastern WA an back over the weekend. It pulled 2 mountain passes in 90 degree heat and did just fine. I hope the new bolts and gaskets hold up for at least anothe 100,000 miles.

Funnly thing though... a lot of Chevy/GMC trucks of the same generation in the RV park we were in with 6.0L engines... most of them with exhaust ticks just like I had when started up cold iron. Once the engine would warm up and everything would swell... tick goes away.

Gary

Every single LT1 car that I've ever owned (esp iron head for some reason) did the same thing. Rear bolt would always stretch or break, and sometimes the next bolt in would too. The symptoms were the same, engine has an exhaust tick when cold, goes away once it heats up and expands. Back 15 years ago when LT1 B-Body cars were all over the place, I can't remember how many posts people had on forums about a valve tick when cold that actually turned out to be an exhaust leak.

If I was lucky to get a LT1 without a broken rear bolt, I would immediately replace the rear bolts with grade 8 and never had a problem. I recommend the same for LS engines.

So this GM problem isn't limited to the LS series. Pre-LS Vortec-era engines were a little better, but not much. Seems to be GM's bane.

Good writeup on the bolt extraction. We've all had to play the same games on some GM head or exhaust manifold. I've even had to do this on a Mopar when dumbarse me overtightened a stud nut...and snap! That one required me to pull the head after just installing it to replace leaky freeze plugs, new head gasket and all the labor, and then had to do it all over again. Luckily Mopar big block heads are a cinch to pull. The valve train is about as simple as it gets and needs no rocker adjustments.

[ReRod]

I wonder how something like this would work for that issue. Looks like it might be quite a bit easier and less time consuming... http://www.kralautoparts.com/index.html

[GASoline71]

Originally Posted by ReRod

I wonder how something like this would work for that issue. Looks like it might be quite a bit easier and less time consuming... http://www.kralautoparts.com/index.html

It's funny you posted that link...

When I was underneath the truck I noticed an empty bolt hole on the rear of the head. I wondered how hard it would be to fab up a bracket to use that hole to fix the leak. I guess these cats beat me to it.

Not sure how he would last long term... but the thought did cross my mind.

Gary

[biohazardbill]

Found this thread as I was looking at possible issues I may have when doing this same fix. A friend has told me about updated bolts GM has, however from what I have readt that changed in 04 from a 10mm head to a 13mm. My truck is an 04 and has the 13mm heads. What bolts did you end up using to replace the broken ones? I don't want to have to do this again if I don't have to.

[storm9c1]

I just use grade-8 bolts of the correct length and thread these days. I've had good success with both hardware store (zinc coated) and automotive grade flanged bolts. No need to overcomplicate it. In most cases, you can use studs with nuts too. Studs especially help on aluminum heads since the stud can/will seize in aluminum but the nuts can be more easily removed. Studs also help lining things up during reassembly. I think the last set I used were ARP (expensive, but I had them in stock left over from another project). Studs also help hold the gasket and help guide the manifold on. But be careful though, some vehicles are so tight that adding studs prevents the manifolds from being slid into place. It can either help or hurt you.

On some engines with iron heads, I've used stainless steel bolts. They aren't as strong but are easier to drill out (than grade-8) if they do happen to break. Harder to weld to SS as well, so choose carefully. Needless to say, you have many options.

[GASoline71]

Sorry for late reply... but that's what I got. Grade 8 bolts from the local auto store. I don't remember the size offhand, but I took one of the stock bolts in and told them I needed a dozen of them in the same size, but grade 8. They had a big ol' box of them.

Gary

[appyacres]

That's it! I ordered the Kral kit for both rear bolts. I was able to remove 2 broken studs with the welding a nut method. They were the 2nd and 3rd from the rear.
The driver side rear had a protruding stud and I was able to get a nut welded on. Even with light pressure using a battery powered Dewalt impact driver, the damm stud broke off below flush. I AM NOT A WELDER, apparently. After 20 plus tries trying to get a good weld on the driver rear, I quit.

The passenger side rear was broke off below the surface. I was able to drill a 1/8" hole nearly on center followed by 10 plus attempts to weld a washer/nut combination. Could not get a weld to stick in the recessed hole for the life of me...

Since there is a ton of room on the passenger side compared to the driver side, I thought it would be worth the attempt to drill it out and try extractor. Quit before it broke off in the hole.

Further drilling I was able to get it close to the 8mm drill size to attempt a tap but the bolt material is so F'n hard that the tap would get hung up. Too afraid of breaking something off in the hole.

My patience has worn thin being on a serious regime of cancer meds at this time. Only good for about 3 hours of this type of work.

While waiting for the parts to arrive I can better utilize my limited energy with a buffer and polishing compound removing all the tree branch scratches incurred while hunting this year.

For those that have succeeded in this adventure, hats off to you...

[lowrodderchev]

Great write up im doing something wrong though my welds hold to the nut and washer but not the bolt lol

[cg285]

Originally Posted by lowrodderchev

Great write up im doing something wrong though my welds hold to the nut and washer but not the bolt lol

welding a nut is always the best option. i see no point in a washer. sometimes it is nec to drain the coolant if the broken stud is by a water jacket (broken stud won't get hot enough). second thing is to crank up the heat. pretend your mig is an edm. the more penetration you get on the stud the better. get it super heated so it will shrink when cooled

[storm9c1]

Did you try taking a metal pick and scratching up the flat surface of the broken bolt in the hole? Weld won't stick to rust, carbon or other contamination. Scratch it up good. Maybe even get a Dremel in there if you can. Then blow it out with compressed air. And try again. You have to be a pretty good welder. Or have lots of patience. Or both. It's still a crap shoot even when you do this job right. I've ended up having to pull heads and drill/tap in a few cases. Some of these broken bolts really put up a fight.

[GASoline71]

Agreed... crank up the amps on your MIG. If I remember correctly I set mine one tick below the "hottest" setting. That way it will grab that stud along with the nut and washer. Not to mention the heat will break loose the thread locker used at the factory.

I just did this again for a buddy that had 2 of them broken off in the head of his '07 Ram with a Hemi. Had the MIG set just below the "hottest" setting.

Gary

[Tom68Lawson]

Thanks Gas for all the info in this Post! I bought a salvage 5.3 LS Motor that had three broken exhaust bolts. The first one took me five or six tries to get it out. I'm a nube at welding and wasn't making good connection on the stud. I kept turning up the heat and speed and finally was successful on 5 heat setting and 6 wire speed. On the second and third bolts I was successful on the second try.

[GASoline71]

Way cool! Glad it was of some help to you!

Gary

[Curbdog17]

Thanks for the tip. You just helped me out a ton.