Exhaust manifold bolts - to remove or not to remove ...

[thefrey]

There are some exhaust manifold bolts on my 6.2 that fell out or the head of the bolt fell off. To fix the ones that the heads fell off, I would need to take the manifold off so while I'm there replace the manifold gasket. Is this a bad idea? I don't know if I want to touch any bolts that aren't broken or loose. I do not have access to a welder so I am not sure if these bolts break commonly when backing them out.

Edit: Manifolds are in decent shape but the bolts are pretty rusty.

 

[Dustin Jackson]

I didn’t have any exhaust manifold bolts break on me but there is no rust where I live. If a bolt is going to break on you it’s going to be one of these.

If you are missing exhaust bolts I would say they are broken off inside already but only way to know is to take the manifolds off.

 

[thefrey]

I didn’t have any exhaust manifold bolts break on me but there is no rust where I live. If a bolt is going to break on you it’s going to be one of these.

If you are missing exhaust bolts I would say they are broken off inside already but only way to know is to take the manifolds off.

From what I could see, I had one bolt that had halfway backed itself out and then another one that I could see the shaft of the bolt with no head. There was 2 other ones that I couldn't tell where it had broken off. But yeah, from Ohio so decent amount of rust

 

[CMoore711]

It is very common for the heads of the manifold bolts to break off, leaving the threaded bolt shaft still in the head. I currently have (2) manifold bolts in this condition on my '13 Escalade ESV (I'm also located in Ohio btw). Just my luck they're the far back ones located closest to the firewall with the least amount space to access and work on... I haven't done anything about them yet.

It's so common there are kits like these made and offered to assist with the process:

GM LS & LT: 2014-2020: 5.3L, 6.0L, 6.2L Exhaust Manifold Broken Bolt Repair Kit - Michele

New kit for on-the-truck hassle-free time-saving repairs. Exhaust manifold repair doesn’t mean a disaster and robbing the shop of productivity, FAST – REAL FAST

promaxxtool.com

 

[Joseph Garcia]

The kit above or kits made by Dorman are popular fixes for broken exhaust bolts. They will do just fine in the short run, and if you ever need to remove the exhaust manifolds in the future, you can replace the bolts at that time. Then, make sure that your replacement bolts are ARP bolts, and you won't have any future breakage.

 

[j91z28d1]

honestly not worth the risk for the average diy guy at home over one bolt head popping off. throw the clamp on it till the afm goes out and you gotta pull the heads anyways.

that's what I'm doing anyways haha.

 

[petethepug]

2013 YXL Denali. Use the clamps until the trans comes out for its 100k major service. The exh comes off when the trans comes out. That’s when you want to do the job.

When the trans is out you also do the motor mounts because with AWD it makes them 100% accessible. Also do the front diff dog bone mounts. I assume you’ve got AWD. Oh yea trans out also means replace the oil press sensor with OEM only because of accessibility.

 

[wjburken]

2013 YXL Denali. Use the clamps until the trans comes out for its 100k major service. The exh comes off when the trans comes out. That’s when you want to do the job.

When the trans is out you also do the motor mounts because with AWD it makes them 100% accessible. Also do the front diff dog bone mounts. I assume you’ve got AWD. Oh yea trans out also means replace the oil press sensor with OEM only because of accessibility.

Don’t forget about the rear main seal while you’re at it.

 

[alvocado]

I'm in OH and have had this issue on two Yukons. If you can see the stud and confirm it's not broken below the head surface, this is an easy repair using a vice grip to extract the stud. I found the other bolts with heads intact came out with no issue provided you use a ratchet and break loose slowly. Replace with ARP bolts. My 2011 Yukon has 220k miles as a reference and I did this a few months ago.

If you can't confirm how low the stud break is, I would agree that it's best left until later and you or a tech has the tools to extract it. Most aren't bad to remove with a left handed drill bit unless it's cylinder 7 or 8 up against the firewall. There's no room and a welder to tack a nut is the only option aside from pulling the head.

 

[j91z28d1]

incase we haven't explained the clamps. they are a work around.. lucky for use the gaskets used are a good multi layer steel. so they dint usually need changed. the clamp bolts to existing holes in the head, and then had a bolt that pushed in the exhaust manifold sealing it up. taking place of the broken bolt.

on mine it worked perfectly, no exhaust leak and it's basically a permanent fix. if I pull the heads I'll replace all the bolts with studs, but until then. these are fine. they have them for the outer most bolts and they have a different style for the inner bolts. I wanna say mine was 30$?

fhey can be a little hard to reach the rear ones to install. you end up laying across the engine haha. unless you have a top side creeper