Exhaust Bolts In Aluminum Heads

[sierrahi]

New to this site, and I have learned much in a short time. I have a 2000 GMC Sierra with a 5.3L . My fist project will be the knock sensors...lol. But... I have a broken exhaust manifold bolt . To fix this I need to remove the manifold, then extract the stud. What I want to know is: What is the best method to accomplish this. First i have to remove all the other bolts. I am a little concerned with applying oxy-acetylene to heat things up. I have been applying a good penetrating oil to all the studs when the engine is hot. So, to make this easier, here is my question. What is the best procedure to remove steel bolts from aluminum heads.

[youcantkeepup!]

once you get the manifold off if you have enough of the broken bolt sticking out, it will come right out with vice grips, i have taken a few out like this, no heat at all was necessary, the broken bolt isnt in there very tight (its not loose either) but i believe that it breaks the head off due to thermal expansion

[croberts]

I have the same problem on my 04 Sierra, and am gearing up to change the manifolds as the original manifolds are almost surely warped. The bolts have thread locker on them from factory so that can make them a pain to remove, make sure the engine is stone cold as heat can cuase steel fasteners to bind up tight in aluminum. Patience, penetrant, patience, tapping on the bolt as you try to remove it, patience, penetrant.

 

Also consider the steel bolt may have grown onto the hole in the manifold flange, so make sure to shock the lip of the flange with a brass drift or something similiar while you continue to apply penetrant. Do this prior to starting the job and also during the removal process.

[rdnkcpa]

I have the same problem on my 04 Sierra, and am gearing up to change the manifolds as the original manifolds are almost surely warped. The bolts have thread locker on them from factory so that can make them a pain to remove, make sure the engine is stone cold as heat can cuase steel fasteners to bind up tight in aluminum. Patience, penetrant, patience, tapping on the bolt as you try to remove it, patience, penetrant.

 

Also consider the steel bolt may have grown onto the hole in the manifold flange, so make sure to shock the lip of the flange with a brass drift or something similiar while you continue to apply penetrant. Do this prior to starting the job and also during the removal process.

 

I just pulled the exhaust manifolds off of my 04 Silverado with a 5.3L. I was shocked on how easy they came out. They were tight, but came out with no problems. I hit them with som PB Blaster and let them soak for a bit, and they came right out. I thought for sure I'd be drilling some bolts out.

[sierrahi]

Thanks for your replies. I tried to move a couple bolts but they were tighter than I wanted to try at this time. I am not sure when I will be doing this job. When it happens I will post. Thanks again!! p.s. Is there a better manifold gasket I should use, or just stick to a OEM style?

[sierrahi]

When I replace the bolts should I be using a product like copper kote? (hi-heat never seez)

[nickvrebel]

When I replace the bolts should I be using a product like copper kote? (hi-heat never seez)

never seize is a good idea anytime you are putting aluminum and iron together.

 

the stock MLS (multi layer steel) manifold gaskets can be reused unless they are damaged. If damaged a stock replacement is the best option.