Exhaust manifold bolts

[dawgn86]

Good morning,

My 2012 Jeep Grand Cherokee / Hemi and 105k miles has a tick on startup that goes away after about 15 seconds. Seems to be alot of debate on the cause from lifters to exhaust leaks. I would like to check for broken exhaust manifold bolts to at least rule it out or if its the problem. My noise is from the passenger bank in the back. No codes.

No problem for me to pull the front right tire and remove the fender lining. From this point I can see / touch the heat shield I know, but do I need to remove it to check for other broken bolts? I dont want to break off any bolts trying to check for other ones.

Any advice / tips would be appreciated.

 

[Astro14]

Tick on startup that goes away after 15 seconds sounds like exhaust manifold leak. A stethoscope will help you isolate the sound even further. It'll be obvious if it's manifold, it gets far louder near the manifold, where lifter ticks don't get much louder as you move around.

Might not be a broken bolt, might have simply loosened.

Heat shield can hide any evidence. If you've got a good mirror, or cheap endoscope, see if you see any carbon tracks - evidence of a leak right at the manifold/head joint. Check all the exhaust ports, top and bottom. Heat shield might need to come off.

If it were mine, I would replace the exhaust manifold gasket. Even if you can't see evidence of a leak.

If you do replace the gasket, Kroil for the nuts/studs. Heat is your friend. A stud extractor can be handy for getting a stud put back in.

 

[SubieRubyRoo]

Astro gives good advice here. Kroil it a couple times a day, and a day or two of heat cycles with a torch should do the trick.

 

[OVERKILL]

You may be able to see carbon witness marks on the head or manifold where it is leaking. Generally, the rule of thumb here is to change out all the studs. They are likely going to break off and require extraction, based on my experience getting our work RAM 1500's done.

 

[StevieC]

Originally Posted by OVERKILL
You may be able to see carbon witness marks on the head or manifold where it is leaking. Generally, the rule of thumb here is to change out all the studs. They are likely going to break off and require extraction, based on my experience getting our work RAM 1500's done.


Good advice. Put some anti-sieze on the new ones going in as well in case by chance you have to change them again at some point. South Main Auto just did a video where he had a heck of a time getting the one stud out of the head.