I have a 71' Cutlass w/ 350 and I need to remove one of the exhaust manifolds because I broke one of the bolts that connects the pipe to the manifold. The question is, what can I do to make this easy? Im concerned about breaking one of the bolts in the block while removing the manifold... I really fear doing that. I have been lubricationg the bolts for the last 2 days with penetrator but becasue the bolts point down I dont think it has been working its way down into the threads. What eles can i do to make sure these bolts are good and loose when i start torqing on them? Also becasue of the awkward angle in which the bolts sit what wrench would you suggest i use to torq them to get the best grip to avoid striping or breakage. I was going to just use a 9/16 ratchet.

 

Use a six point socket so you don't strip the head and go for it.
If they don't turn report back for more instructions.

Mine were on since it was built and they came right off with no problem three years ago.
I've never had any problems with those bolts on any old car I've had, famous last words.

 

Don't forget that if your 9/16 bolts are a little rusty, or rounded then use a metric six point 15mm socket-tap it on gently with a hammer if it is tight...if it is severely rusted use a 14mm socket and a bigger hammer

 

Hopefully you won't have much trouble removing the bolts that hold the manifold to the head. The bolts that always seem to cause the most trouble are the ones holding the exhaust pipe to the manifold. I suggest using PB Blaster as a penetrating oil for at least 2 days before attempting to remove the manifold.

 

Hello Blue Vista d
lassite21 aksed for advise for loosening exhaust bolts , I am looking at removing the exhast manifolds too. Any advise appreciated

"If they don't turn report back for more instructions" ??
Thanks

 

I will put my 2 cents in on this, always heat these nuts & bolts up with a torch to prevent from breaking. [glowing hot] IF you can get a drill on the under side of the bolt that broke off in the manifold I would drill it out to avoid removing the manifold from the head which may open up pandora's box..

 

Fellers this is a 15 year old thread. Not that the info given isn't helpful or anything. I always enjoy a good exhaust manifold thread!

 

Never noticed this, how did this post get re-listed I wonder ??

 

I'd say the recent poster did a search and found a relevant thread, which is cool but this one might be a little too stale.

 

Might have been a deep scroll and auto-loaded a "related thread". It's happened to many, myself included. It's a newer thread, you scroll down and end up posting in a crusty, old thread by mistake.

 

In general, I would use penetrate oil, let it soak for as long as you can stand it. The penetrating oil will wick itself up the threads if it gets in there. Overnight should be fine. I know this sounds counter-intuitive, but try to LOOSEN the bolt ever so slightly. You do not want to tear off the head of the bolt, so take it real slow. Don't gorilla force it. Use a 6 point impact socket on a good, long-handled ratchet if you can fit it in there. If you do feel it move, then re-tighten it, then work it back again. Basically rocking the bolt back and forth to get it moving.

If you need heat, heat the head and manifold area around the bolt. Ensure the spark plug wires or anything else you don't want torched are moved out of the way. No need to heat the bolt itself as you want the hole to expand and break the grip, not the bolt. You can heat the bolt but if you do, it could expand and make itself tighter, but could break any rust bond. Let it cool again and give it another penetrate treatment before trying to move it.

Later Olds heads (smog era) had only the center exhaust hole that was blind. The others were drilled all the way through near the spark plug to help with the penetrate soaking. MUCH easier to deal with.

There's other ways of skinning this cat, but that's how I'd approach it.

 

Olds exhaust manifolds, while being poor flowing hunks of cast iron, have excellent placement compared to other engines and rarely have seized bolts to the head. Not having spark plug boots constantly burning on manifolds and headers is nice. Also not having bolts directly into coolant, is also a nice touch. The only ones I have break off for the most part, is the top center bolt. That one is optional on headers and can be deleted. Heat, soak and repeat to remove.

 

Yeah that center bolt is the only one on my '66 425 that isn't open on the top of the cylinder head. I can see how that would be the problem child. The other four bolts are open so at least you can get some penetrating fluid into the threads.

I tell you what though. On the passenger side, the AC compressor has a bracket that uses one of the manifold bolts to secure it and it is buried. BURIED I say! It is totally in never never land underneath the bracket. I used my fancy borescope to locate it actually as I could not make heads or tails of where that bracket was mounted without removing a bunch of stuff.

 

Also be alert to those bent over bolt head locks. OEM or otherwise. Total PITA.