Snapped exhaust stud in head - recommend me a garage in S.E. Wales?

Lum

Thought I'd blown the exhaust manifold gasket, or possibly the turbo gasket on my car (1993 Nissan Cefiro) turns out it's actually snapped 3 of the exhaust studs, which is not exactly rare on these engines after 20+ years.

Bad luck for me, there's 12 of them, two per port, and it's the back two that have snapped leaving one port completely unsecured. The manifold is made of six separate pipes, not a flat plate, so I can't even bodge it with a new gasket and tightening the others. It's going to need drilling out and helicoiling, unless someone can actually get an easy-out to work!

The place I took it to had a go but there just isn't enough room to get in there without taking the head off which I am reluctant to do. They've suggested I ring around and see if there's any places "with an angle drill or something" who can do it.

Does such a thing even exist, and can anyone recommend a place that can do it? Preferably in the Caldicot/Magor/Chepstow area but I don't mind travelling.

Here's what we're working with. The offending studs are accessed down that little hole on the top right of the picture.

mrmechanic

I think you will probably struggle to get in to drill the broken studs out.
Is it possible to remove the manifold out of the way and get someone with a mig welder to weld a blob on whats left of the broken stud, then get a grip with a pair of vice grips.
The heat generated is usually enough to get the broken part moving.

You may have to have a few attempts as quite often the welded blob breaks of, but pacience usually pays of.
Worth a try.

Lum

It may be possible, but is somewhat beyond my capabilities. (I've dabbled a little with oxy/acetylene many years back, probably forgotten how to do it) so comes back to my original question of finding a place.

The lower of the two studs you can't even see without a mirror and a torch, so I'm not sure you could get a welder in. I'm also not sure if the snap is internal or external. The manifold is quite low down, you can only just see the heat shield in that pic (visible a little but just below the J pipe)

If the head does have to come off I'll use it as an excuse to upgrade the head gasket Cometic seem to be the preferred choice for an RB engine?

mrmechanic

Might be worth while phoning around your local garages and asking if they would be willing to remove the manifold and try and get the head of a mig torch into see if its possible to get a blob onto the broken studd.

More than likely be possible once the manifold is of, worse case senario is the manifold will be coming of anyway if they need to remove the head.

Meant to say you won't be able to get near it with oxyacetalene, as to much chance of setting something on fire.

Lum

Oh this is with the manifold and heat shield removed. It's still pretty damn hard to get at.

Still after a specific garage recommendation. This area seems to be mostly dominated by overpriced fast-fit type places with suspiciously clean floors and who will probably be confused by my car not being in any parts database (It comes up as a Primera if you try) and its lack of an OBD port.

spacey2012

Once the bolt head has snapped, the bit holding it in under pressure is gone, use a removal bit in a drill and see if it turns.

Lum

No way you're getting a drill in there unless you have one that can do a 90+ degree bend! It's not something I want to attempt myself even if such a drill does exist.

The exhaust studs are seriously buried on this car.

mgdavid

google 'thread doctor' and your nearest big town/city. There are specialists just like the Mr Dent removers... or just ask around the local garages, they will know who to recommend.

Lum

"thread doctor" gets me forums about Doctor Who and discussion of repairing a 60s-vintage Chrysler Newport!

The local garage I use and trust can't recommend a place and everywhere else is a big chain, hence me coming here and asking if anyone knew anywhere specific, otherwise I'm just plucking random garages (min 30 minutes drive away) from the yellow pages.

colino

Is there any part of the stud proud of the surface? I bought a set of what is called Impact Stud Extractors after using one of the smaller versions on a broken off abs sensor bolt. It isn't really an impact anything, it is more like a drill chuck that you can use a socket on the top of, or a spanner from the side, to grip on to what's left of the stud and then (as has been said above) with the clamping pressure off, it will then turn it out. It really only needs 3-4 millimetres protruding and about 3 inches "head room" to give access.

happybiker

From the sounds of it, you don't need a garage, you need a jobbing engineering shop. I've tackled many such jobs, always with the head on a bench in front of me. You risk wrecking things by trying to cut corners and do it with the head in situ, snapped studs can be time consuming and one needs lots of patience to get them out without damage.

Take the head off.