As you can see in the pic I have two broken studs at the very right hand end on the exhaust manifold (number 1 cylinder I believe). Essentially there's nothing holding the manifold to the head at this end. I have now idea how this happened, perhaps they were overtightened at some time? Anyway, I'm hoping that if I fix this the engine will run a little smoother and quieter and that I wont get any more whiffs of exhaust gas like I do now.

Obviously to fix this I have to take off the manifold, pull out the studs, find and fit new ones and bolt it all up again. I have the following questions:

How hard do you reckon it will be to get the studs out? Any tips?

Will the manifold have to be unbolted from the exhaust pipe just below the O2 sensor? If so will I need a gasket there? (the Haynes manual doesn't mention it).

Should replacements be easy to get from a parts place or should I got to Mitsubishi first? Places I have asked want me to bring the stud in to match it up.

If I have to take the O2 sensor out (so I can get the heathshield off to get some room to work), will that be hard to do? I hear these things can get stuck in very tight. Also are they easy to damage?


http://www.uq.edu.au/~zziwilki/manifold.jpg


I do realise that I ask for a lot of help on this forum and I really appreciate the assistance I have received from everyone. My car runs heaps better now (even if I now realise that the ECU is shot) and my confidence at fixing things is growing fast. I hope my questions help someone else in time.

Obviously to fix this I have to take off the manifold, pull out the studs, find and fit new ones and bolt it all up again. I have the following questions:

How hard do you reckon it will be to get the studs out? Any tips?

for the broken studs, i guess you'll have to grab them with some big multigrips and get them out (i'm assuming the studs have snapped - mine did this you see, so you can grab a little bit of it and undo them - if not, you'll need to drill them out and retap or something). as for the other studs, just lock two nuts together using two spanners, then use one spanner to get them out of the head. if that makes sense?... also, dont jsut replace the 1-2 that are broken, do the lot... if one is broken, chances are the others are weak.



Will the manifold have to be unbolted from the exhaust pipe just below the O2 sensor? If so will I need a gasket there? (the Haynes manual doesn't mention it).

if you take off the manifold from the head, you should be able to move it off the studs in the head. the flex pipe under the car allows you to do this without having to take the whole maniofld off. you'll just need the exhaust manifold gasket to the head only. support the manifold so all the weight doesn't ruin your flex pipe though.



Should replacements be easy to get from a parts place or should I got to Mitsubishi first? Places I have asked want me to bring the stud in to match it up.

take one of your existing studs somewhere. mitsu might still sell them, but also try a place like autopro, repco or sprint auto parts (basically, a decent place that actually knows what your talking about, unlike supercheap auto :doubt:), astrons were a common motor, i dont think you'll have trouble finding studs :p



If I have to take the O2 sensor out (so I can get the heathshield off to get some room to work), will that be hard to do? I hear these things can get stuck in very tight. Also are they easy to damage?

shouldn't have to take it out... see my earlier point about the manifold being attached to the car.



I do realise that I ask for a lot of help on this forum and I really appreciate the assistance I have received from everyone. My car runs heaps better now (even if I now realise that the ECU is shot) and my confidence at fixing things is growing fast. I hope my questions help someone else in time.

tis cool, any time. that's what a forum is about, helping other out and getting questions answered. :)

feel free to ask more questions if you dont understand something, it's what it's all about :)

You shouldn't have to remove the Oxy sensor to remove the exhaust manifold. If you follow the wire from the sensor there should be a large white plastic plug that is in a clip connected to the chassis, near the radiator. Just pull the plug from the clip and you should be able to see that it can be unplugged. I'll post some pics in the morning if I have time.

Don't worry about asking questions, as you have always done some work before hand and have eliminated some possible causes. I've learned more about cars from this forum, my dad and doing work on my car, than I've leared from my mechanical engineering degree so far. It's when someone wants to be spoonfed answers without doing any work themselves that people get pissed:doubt:. The stupidest question is the one that was never asked.

Prior to trying to remove the studs apply lots of CRC or WD40 and allow to soak, preferably overnight. If possible apply several times.

Rob

the easyest way to get the stud out is, buy a new very sharp high speed drill bit and a extractor bit (reverse thread drill bit). now u carefully drill the centre of the stud but don't go to deep. then take ur extrator bit put it in the hole and turn anti-clock wise untill the stud is out. i had a bolt snap off my tranny and thas what i had to do.

Thnaks for all the help and info everyone.

Magnabuff, are you saying that you don't think I'll be able to get the manifold clear enough to let me get at the studs to use a spanner or pliers, or to get a centrepunch and drill in there? I was not going to use the drill and extractor bit method myself - it's too hard to line up.

The manifold isn't cracked, that's just a compression artefact in the picture. Here's a detail:
http://www.uq.edu.au/~zziwilki/manifoldetail.jpg

I had intended to see if they would come out with a sharp rap with a hammer, lots of WD 40 and a big pair of multis. If that didn't work I'd try some stilsons, and if that didn't work I was going to grind and file two flats on each stud and use a spanner/shifter.

Maybe I'd be better off going to an exhaust shop? Might not be an expensive repair?

Hey same thing happened to me when i was replacing my manifold.

I had to take the manifold off again so more of the stud was exposed. Luckily for me they came out with pliers :D

Take the broken ones down to an auto store ( i went to auto one ) and get some new studs. Make sure you take an original nut so they can see if it would go on.

Also, they have to be high tensile.

EDIT: It depends, if they have to remove the manifold they are going to charge you for the labour + new gaskets (Manifold + flange gasket)

Thnaks for all the help and info everyone.

Magnabuff, are you saying that you don't think I'll be able to get the manifold clear enough to let me get at the studs to use a spanner or pliers, or to get a centrepunch and drill in there? I was not going to use the drill and extractor bit method myself - it's too hard to line up.

The manifold isn't cracked, that's just a compression artefact in the picture. Here's a detail:
http://www.uq.edu.au/~zziwilki/manifoldetail.jpg

I had intended to see if they would come out with a sharp rap with a hammer, lots of WD 40 and a big pair of multis. If that didn't work I'd try some stilsons, and if that didn't work I was going to grind and file two flats on each stud and use a spanner/shifter.

Maybe I'd be better off going to an exhaust shop? Might not be an expensive repair?

to get those out, you'll need to take the manifold off and then just grab them with big multigrips and undo them.

dont waste your time trying to drill them out, etc etc...

chances are the gasket will need replacing anyways cos of the leak that is there.

It was always my intention to unbolt the manifold and pull it away from the head. I have already bought a new gasket.

That crack is sooooo damn common. I have one in mine at the moment:redface:, I have no money for extractors and it's only a hairline fracture when cold. I went to look in a pull it yourself wreakers and every single manifold that was left had the same crack:doubt:. About 10-12 in total.