Hi all, I could do with a little advice, I really want to remove my exhaust manifolds as i want to replace the gaskets.
Trouble is, the studs/nuts are pretty gone and im worried that i would never get them to move, also, will i need to drill the remainders out in the heads
Tom

Good Luck......You'll need it.

yars. I know but, would be good to get them off.

Go steady with them and you should be ok. Get onto ECAS 2CV parts (other suppliers are available, but frankly, they're not as good ) before you start and get hold of four new exhaust manifold studs, four new brass manifold nuts and eight new star washers. You'll need a single hex socket and lots of WD40 to shift the exhaust bolts, inlet ones are usually easier to remove since that end is less hot. Obviously.
Once you've got the manifold off, lock two of your new nuts up against each other on the exhaust studs and wind them out. Put your new ones in being careful not to strip the aluminium thread, which is very easily done. (This also goes for refitting the inlet manifold bolts.) Clean up the mating faces on the heads and the manifold, checking to see if the manifold face has been eaten away by leaking exhaust gases. Stick your new gaskets on with a light smear of copper grease on either side, put the manifold back on (which can be a bit of a struggle, but it goes on eventually), tighten everything back up (DON'T use the torque settings in the Haynes manual) and that's that.
You might have to drill out a manifold stud if you can't undo it with the "two nut" technique. (Or, of course, your manifold studs might be in good condition and not require replacing at all, but in my experience it's worth having new studs and nuts when you do this job since they cost sod-all and the old ones are generally knackered.) If you do have to do this, just be extremely careful not to knacker the thread up, or at least make sure you buy an M7 helicoil kit before you start drilling. Good luck!

If the nuts are very rusty, which is normally the case, I find it's safer to split them with a small, sharp chisel than trying to undo them as it's easy to shear a stud.

Personal preference, but I put the exhaust gaskets in 'dry' and use ordinary grease to hold the inlet gaskets in place.
Once it's up and running again, don't forget to check the torque on the exhaust manifold nuts after 500 miles use and once more at about 1500 miles as they do settle in.

ken

Got the very rusty studs off Dudleys original engine with Mole Grips and about 1/2 a can of butane in my blowtorch - get them red hot and then carefully apply turning force..

If the exhaust nuts feel like they don't want to move, DO NOT keep applying more torque until the stud breaks, it will be your free pass to a whole world of pain.

Much better to destroy the nut getting it off, either splitting it with a chisel as Ken said, cutting one side off with a grinder or hacksaw, or drilling into it to weaken it before knocking it off with a chisel.

Even when it looks realy crusty from the outside, the thread under the nut is usually quite serviceable, so don't try and get the studs out unless they come out on their own. Minor damage to the thread isn't too much to worry about, it can be cleaned up afterwards with a die nut.

DO NOT BREAK THE STUD!

Have to agree with the caution. On my spare engine, I managed to get the nuts off by smashing an old 10mm socket onto the nuts. With a good soaking in penetrating oil (proper stuff, not just WD40) the nuts came off with no hassle.

Later tried removing a stud on another head and it sheared very easily.

do not try to remove a stud unless you have to

the bottom of it is exposed and so will be corroded into the alloy, they always drag half the alloy thread out with them.

sean

As a penetrating fluid, one of the most effective is Eucalyptus Oil (it smells good, too!). Even more effective than the Aussie cricket team.