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[Webby the Bear]

Thanks guys. I don't have access to the heat until a couple of weeks time. Will I be able to knock them out without heat?

[terry paget]

Hi Webby. I am confused. There are two downpipes, joined to two central pipes, on the V6. You say you have successfully undone one of the screws, but broken one off. Right? How about the other downpipe?
If you have broken a screw off, you will have to drill it out. Only alternative is to remove the downpipe from the manifold and take it to a nice engineering shop, who will get out the remains of the screw for you. He will employ a trick; he will weld a rod to the remains of the screw, then unscrew it - the electric welding heat frees the rusted thread a treat.

To remove the downpipe you will have to heat up the downpipe studs and the nuts on it to release them from the rust. I did this prior to my clutch change. The nuts are a funny size, a bit smaller than 16mm across flats, so best to use a full hexagon socket, not a conrners only socket.

I cannot see how hitting it with a hammer will achieve anything. It is not a stud stuck in a hole, it is a screw stuck in a thread.

[Webby the Bear]

Hi Webby. I am confused. There are two downpipes, joined to two central pipes, on the V6. You say you have successfully undone one of the screws, but broken one off. Right? How about the other downpipe?
If you have broken a screw off, you will have to drill it out. Only alternative is to remove the downpipe from the manifold and take it to a nice engineering shop, who will get out the remains of the screw for you. He will employ a trick; he will weld a rod to the remains of the screw, then unscrew it - the electric welding heat frees the rusted thread a treat.

To remove the downpipe you will have to heat up the downpipe studs and the nuts on it to release them from the rust. I did this prior to my clutch change. The nuts are a funny size, a bit smaller than 16mm across flats, so best to use a full hexagon socket, not a conrners only socket.

I cannot see how hitting it with a hammer will achieve anything. It is not a stud stuck in a hole, it is a screw stuck in a thread.

That's what I though mate.... but it can apparently be knocked through as per previous comments?

[biggriffin]

Mr bear.
 did the flanges have nuts and bolts or just bolts.
if just bolts then the downpipe flanges are threaded and the tap out with a dot punch when hot should work,will not work cold..
if they are nuts and bolts then they have already been drilled are probably just corred in the flange,they should knock out with a punch..

if you have to remove dwn-pipes, selction of 16mm and 15mm, sockets, lots of release type spray,and undo forwards n backwards lots of spray.

[05omegav6]

Mine used to have bolts on it, which I simply knocked out ... hence the suggestion

[Webby the Bear]

theyre just bolts

as I no longer have access to the heat im thinking drilling (if the hammering doesn't work cold) is the only option?

[biggriffin]

Easiest way to drill is dwn-pipes off.can be done on car,but its a pain.
 as when removed can be put in a vice,and get at remains of bolt easier.

[Webby the Bear]

Very true mate. Without the heat though I don't think it's going to work any other way 

[terry paget]

I've drilled them out with the pipe on the car. My technique is to use new drill bits, and not to rush it. Centre punch the centre of the bolt, and start with your smallest drill (1.5mm?)  They come in packs of three, When you get in 5mm or so, use a 2mm drill to enlarge the hole, then a 3mm. Then revert to the 1.5 and proceed  slowly and carefully. What you want to avoid is breaking off a drill in the bolt. When you break through with the 1.5, withdraw carefully, then put through the 2mm, and so on up to the bolt size.

I have a pit, which makes it easier. Once I broke off a bit in the bolt, and took it to a garage who drilled it out all right, with the car on a lift. It cost me £5 cash.

That's why it's worth striving to get the old bolts out, using lots of heat and patience.

As said before, if i remove the pipe and take it to Mr. Leat, local engineer, he will get them out for me using the welding rod trick, charging £10-20, depending on number of bolts to be removed.

[Webby the Bear]

Thanks Terry.

As said I'm going to try and get the nuts off securing downpipe to manifold so I can remove it from the car and try and drill these broken fasteners out.

I like to have plans of attack. SO. When I get the downpipe off I may choose to replace it as well. My reasoning for this is that I had to cake the centre silencer to downpipe in so much exhaust paste I think I've probably ruined the tapered gasket.

If I was to replace both downpipes as well (preventative as I've also got a hole in the passenger downpipe) am I right in thinking that i'll need a total of 4 new gaskets..... 2 of the tapered ones for downpipes to centre silencer...... and 2 of the thin ''ring'' gaskets between manifold and downpipe???

If so where do you get these from... ECP don't have any.... is it dealer time? 

[biggriffin]

There is only 2 gaskets on whole system. Downpipe to manifold the round flat one, re-use and put a smear of paste on both sides before refitting. On the other joints use paste aswell.

wont say how i do them as all the purist, and you must do it this way guards, get up set and start shouting

[Webby the Bear]

Got ya! When I removed the centre silencer to downpipe bolts (well half of them  ) there felt to be a thick gasket attached to the downpipe flange.... I'm presuming this wasn't a gasket and was actually part of the pipe?

[Andy H]

Mine used to have bolts on it, which I simply knocked out ... hence the suggestion

That is because yours have already had the threads drilled out of the downpipe flanges.

When it left the factory the flanges were threaded.

[Webby the Bear]

So basically I'm trying to drill these out in situ. if I cant do that then ill need to get the downpipe off and try and drill them out off the car. if all else fails ill have to replace the downpipe (if I cant get the broken studs out).

so it all rests on the nuts coming loose to the downpipe to manifold connection...... if that doesn't happen then im buggered lol

[Andy H]

So basically I'm trying to drill these out in situ. if I cant do that then ill need to get the downpipe off and try and drill them out off the car. if all else fails ill have to replace the downpipe (if I cant get the broken studs out).

so it all rests on the nuts coming loose to the downpipe to manifold connection...... if that doesn't happen then im buggered lol

Drilling the snapped bolts out is a pain but perfectly achievable.

When I changed my exhaust 4 years ago I snapped 3 bolts. I carefully drilled each bolt out using a tapping size drill and then picked out the bits of bolt thread, finally cleaning up the threads with an 8mm tap. Took me all day.

When I changed the exhaust again 3 months ago I only snapped one but I was fed up with cleaning up old threads so I drilled them all out.

The stainless flange is very tough so you need good sharp drill bits. I resharpened mine a couple of times that day.

I wouldn't bother removing the down pipes, before you know it you will be removing the manifolds to change the studs in them too........