Exhaust Manifold Studs Removal

[larryt]

Hi Guys!

 

Im having some issues removing a few of the nuts and studs from the exhaust manifold. i was noticing some smoke from the manifold and some of the nuts were very loose, these came out with little issue. however i am left with a few which are rusty/cheesy/rounded nuts.. all of the studs so far that have come out have come out with the nut rusted on.. i have managed to angle grind one of them off, but the bottom rear one i do not have access to whilst the steering box is it place, i also cannot remove the steering box because.. the manifold is in the way. never ending story with this flippping car!!! starting to regret ever starting a rebuild :'(

[2002Scoob]

PB Blaster is your best friend here. A set of good vice-grips too.

 

When I disassembled my motor, I had some stubborn exhaust studs/nuts as well. some ended up pulling the studs out completely with the nuts still attached.

 

The best thing to do is just plan on replacing your studs/nuts with new studs, and new copper nuts so you don't have to worry about it in the future.

 

Once you get the manifold off, just thread on two good nuts, lock them together, and back out your exhaust studs. Clean out the holes thuroughly with brake cleaner or your choice of degreaser so they're bone-dry, and install new studs with threadlocker/thread sealer (most of the upper studs are open to oil on their back-sides, and will weap oil and cause smoking if they're not sealed properly.) This will also make sure the next time you pull the manifold, you're removing the nuts and not the studs with them.

 

Good luck!

 

 

[wegweiser]

I just did this operation on a cylinder head. I was lucky enough to have it off the car, however. An Oxy/Acet torch and quick use of a 12mm wrench did the job. The key is not stripping the nut in the process. It took me about an hour to do all 8. 

Edited May 4, 2017 by wegweiser

[Simeon]

The RHD manifold is a bastid. That rearmost lower nut is basically in a hole between the two exhaust runners. If that is rounded it's going to be very tricky to get it out. Not even sure you can see it from underneath. 

 

Not planning on taking the head off are you?

 

[larryt]

3 hours ago, Simeon said:

The RHD manifold is a bastid. That rearmost lower nut is basically in a hole between the two exhaust runners. If that is rounded it's going to be very tricky to get it out. Not even sure you can see it from underneath. 

 

Not planning on taking the head off are you?

 

 

 

i can see it from underneath as the car is up on stands, i can lay underthere and i can get to it, but its very very tight in there.. i have purchased a set of vice grips and a new blowtorch.. this will be my first port of call. 

 

otherwise i may have to drop the engine out through the bottom of the car whilst its on stands... not ideal but probably easier that removing that b*strd rear stud

[Healey3000]

Yikes!  I thought the LHD cars were bad enough but this is just diabolical.

 

Pulling the head sounds like less work than dropping the engine.  Plus, you get to put the whole mess on a bench to work on.  I completely feel your pain.

[laundromatt]

Following along....  I plan to do this too.  Not looking forward to it.  

[flagoworld]

So you have them removed from the head but cannot get them out of the manifold due to the nuts being stuck? Go under the car and separate the down pipe from the resonator. It's a simple tri bolt clamp i think. Pull the manifold and down pipe up through the engine bay. Remove the nuts as suggested above. Drop it back down in.

 

(That's what I did... to be fair I did it with the engine out, but I believe there is still enough room to pull the manifold and down pipe up and out)

[Simeon]

Your can get a socket on it with some fiddling from up top. Maybe if you can get one of those ezy out type sockets that much into rounded nuts as you tighten them?

[larryt]

10 hours ago, Simeon said:

Your can get a socket on it with some fiddling from up top. Maybe if you can get one of those ezy out type sockets that much into rounded nuts as you tighten them?

 

there doesnt seem to be enough space to get anything onto the nut. im potentially thinking of using a large chizle and a hammer and just trying to take the head off the stud. 

 

at the moment im left with three still in, 1 is round 1 is out of reach (bottom rear) and the other cant come out because i cant get the other 7 out to pull the manifold off and unscrew the stud.. never thought changing the manifold would be so difficult! should have just filled the edges with liquid gasket! hahah

 

will update after tomorrow when i will be trying to get them out again

[2002Scoob]

Vice grips no work?? I thought they fixed everything... 

 

Destroys anything you're clamping em' to, but they grip like a bear trap.

[2002Scoob]

Other possibility, like you mentioned it to try and chisel the nut in half, or perhaps get up in there with a dremel with a cut-off wheel or hack-saw to try and cut it?

 

Edit---maybe the chisel idea is a bad one thou... you do have a steel stud threaded into soft aluminum, you don't want to deform the holes. 

 

I'd personally stick with PB blaster, vice-grips, or trying to cut and split the bolt with a dremel, if there's room. 

Edited May 5, 2017 by 2002Scoob

[larryt]

54 minutes ago, 2002Scoob said:

Other possibility, like you mentioned it to try and chisel the nut in half, or perhaps get up in there with a dremel with a cut-off wheel or hack-saw to try and cut it?

 

Edit---maybe the chisel idea is a bad one thou... you do have a steel stud threaded into soft aluminum, you don't want to deform the holes. 

 

I'd personally stick with PB blaster, vice-grips, or trying to cut and split the bolt with a dremel, if there's room. 

 

good thought about the chisel, its a bad idea and may damage the block. i think im going to try an old school hacksaw and just work slowly on it! im sure itll eventually come off hahaha 

 

first job tomorrow, pb blaster and mole grips, second job 4hrs of hacksawing in a tiny space and smashing my knuckles on everything 

[2002Scoob]

If you can saw diagonally or perpendicularly through the bolt at least part way, then you could attack it with the chisel and try to crack it, or at least break the corrosion that's locking the two together enough to un-thread it. I've had to do this a few times in my automotive life. 

[TobyB]

Oh, oh, I know this one-- air body saw.  If there's room to get it into place...

 

It's a pmeumatic hacksaw like no other.  Buy lots of blades- if they don't break, you burn the teeth off 'em  (go as slowly as you can)

On this side of the pond, you can find them for $25- $30 at the large import tool emporia...

 

t

 

Edited May 5, 2017 by TobyB