Typical engine tick became louder after oil change

[CaptKirk]

Well, decided to save myself the cost and do it on my own. I would have been completely done in about 1.5 hours if it wasn't for the broken studs. It's a pretty simple job once you take out the fender liners. The passenger side is a breeze and the firewall bolt on the driver side can be had at if you have a swivel and about 2 feet of extensions.

 

Two studs were broken though, unfortunately the two furthest against the firewall on driver side where I was hearing the ticking from. I was able to get one out with vice grips (they both snapped right at the bolt head so there was some sticking out), but the other twisted off flush when I tried it the same way. That's where the real fun started. My exhaust is super rusty, so wasn't able to separate the cats, or get all the bolts to pull the manifold off completely. Had to wedge bricks against the driveshaft to bend the exhaust enough out of the way, then call my friend over who had a welder. Took us 4 or 5 tries, but finally we got a good weld on it and it backed out pretty easy.

 

I guess we should consider ourselves lucky that the bolts weren't anymore seized and that only 2 broke and 1 came out with vice grips... still. took around 6 or 7 hours because of all that to finally get the truck buttoned up. That was with the help of my friend too. Going to hope it holds, we'll see after a few heat cycles. 18 lbft seems really weak for a torque spec on mani bolts, I set them at 20.

 

Anyway thanks for chiming in everyone and helping diagnose that. Total cost was about 30 bucks with shipping, and half a day.

[Downeast Johnny]

Congratulations on getting the problem fixed.

 

The torque specs are based on aluminum heads and relatively small (diameter) header bolts. I wouldn't second guess the manufacture on that. Also; I believe that the OEM bolts are single use bolts, (Torque spec takes them close to failure) and so I especially wouldn't want to over torque them.

[CaptKirk]

Good point. The replacements that came looked to be pretty stout and the heads were 12mm instead of 10. No wonder they're always snapping off if the torque spec takes them close to failure....Although wouldn't be the first thing that's designed to start falling apart once the warranty expires, that's basically an engineer's job in a lot of industries.

[Downeast Johnny]

Were your replacement bolts OEM or aftermarket?

[CaptKirk]

I used these: http://www.rockauto.com/en/moreinfo.php?pk=5789562&cc=1412042&jsn=10431

[Downeast Johnny]

I went looking for more info on these bolts and found a pretty informative thread about this very common problem, solutions, and bolts.

 

Looks like your good to go for a good while with the Dorman bolts as I assume that they are the upgraded bolt specs, (But if I were you, I would make sure of that).

 

Looks like there's a pretty good argument for replacing the OEM bolts every 50,000 miles or so.

 

http://www.gmc4x4.com/topic/2261-the-broken-exhaust-manifold-bolt-60-ls-plague/

[CaptKirk]

oh wow, surprised I didn't find that in all my googling.

 

I will definitely keep the ARP hardware in mind. Once I have the extra cash I'd like to go in and do CAI, LTs, a real exhaust, and a tune. I'll add the header bolts onto that plan for sure.

 

Thanks for yalls help once again. Hopefully others find this thread worthwhile

[Downeast Johnny]

I've known for a good while that these bolts were problematic but had no idea just how big the problem is that GM has been ignoring.

 

I always hope that other guy's find helpful info in these posts.

 

Keep us posted on what all you do with your truck. (And pics after you take the step's off)