Broken exhaust manifold bolt

[drakon543]

Yep. Seems to happen to lots of LQ4 and LQ9 engines. The factory bolts are crap. I would go ahead and replace them preemptively before you need to weld them out. Does anyone have a good go-to replacement? If it were me I'd select a stainless steel part.

So I'm surprised you're seeing this on a newer engine?

i used to work in a shop where we were either fixing broken manifold bolts regularly or removing the manifolds for headers. soon as i started and they were comfortable with my ability i was given every job like this because it just usually sucks. i also now work in a production facility dealing with alot of heat and anywhere that has a stainless bolt you end up screwed. hardened bolt with some anti seize is all you need.
anyway ive used these tactics quite a bit for manifold bolt issues but a few years ago i learned a new one. if your plan is to remove the manifold entirely cut the heads of all the manifold bolts off. one of the big things that binds these bolts is the contraction of the manifold. so cut the heads of the bolts off and pry the manifold off which still wont be easy. however once you get it off now you have solid studs a simple stud extractor will remove or a pair kf vice grips.

 

[jsoltren]

Hmm. Good point about stainless potentially being too soft. Perhaps a harder bolt than the GM spec would be advisable? Or perhaps moving to studs?

 

[drakon543]

they have stud kits through various brands but if anyone goes that route i suggest atleast picking a good brand maybe arp or similar. with a stud you have 2 chances for something to safely come out or off incase of a nut. but if you use all studs you could end up fighting a manifold back off if your seal goes. alot of heat goes through there so if anywhere on a vehicle the exhaust manifold is not one of the places to go cheap.

 

[kbuskill]

I just purchased Stage 8 locking bolts for my new headers. I haven't installed them yet and I have no prior experience with them but the reviews are good and I am hopeful to never have any issues.

Stage 8 part # 8900 in case anyone is interested.

 

[1BADI5]

I got ARP hardware when I bought my TSP headers and y pipe on Black Friday