Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Webby the Bear on 13 February 2014, 19:02:11
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Hi guys,
Me and the Mad Mechanic went to do my exhaust a couple of weeks ago and found the downpipe to centre silencer bolts were, as expected, not going to budge.
Tomorrow I have the full use of the workshop to do work on my car 8)
I was going to do it with the acetylene torch to heat up the flange(s) cherry red, then buzz gun the bolt out.
IF not is hacksawing them off and replacing an option? If so can someone baby-step me the procedure?
Thank you.
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Ps, are the exhaust clamps going to give me any grief (the ones that attach the centre silencer to the rear silencer)? Or will I have to saw these off too? ::)
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Use a socket/spanner rather than impact wrench.
If you shear it, you'll have to drill and retap (preferred) or drill and nut and bolt it.
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Thanks TB.... so heat is the way to start then ratchet it off? :)
If they still won't budge is the hacksaw a way to get them off.... or is it just drilling the only option?
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Ps, are the exhaust clamps going to give me any grief (the ones that attach the centre silencer to the rear silencer)? Or will I have to saw these off too? ::)
What are you actually renewing, all or part of the zorst? :-\
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Ps, are the exhaust clamps going to give me any grief (the ones that attach the centre silencer to the rear silencer)? Or will I have to saw these off too? ::)
What are you actually renewing, all or part of the zorst? :-\
I've got a full cat back system kindly donated by NickW. However the other exhaust pipes are actually in good condition so I'm just (for now) going to replace the part that's bad which is the drivers' side centre silencer.... it just so happens that its that side that the fasteners are stuck in ::) the other side came out ok.
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Hi Webby
When I did mine the studs sheared off flush to the flange, did as TB said drilled studs out and replaced with bolts and copper covered nuts
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Am assuming you are fittin a complete system,if so ignore the rear.
1st clean up with wire brush dwn pipe to system bolts.
2 get 12/13mm sockets n spanners ready
3 light the blue spanner
4 heat each bolt till nice n red
5 try to undo said bolts
6 when bolts removed,take whole system off as one piece.
7 drill out dwn pipe flange to 5\16or 8mm
8 fit new system,use some exhaust sealent on flanges,and were tail section joins,line up,and check clearance on rear wishbone then tighten up..
if the bolts snap in the dwn pipe flanges then you will need to drill them out using a 2-3mm drill to start as a pilot then drill out to 5/16-8mm.
use m8x 75 nuts n bolts and washers to refit dwnpipes to system..
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Ps, are the exhaust clamps going to give me any grief (the ones that attach the centre silencer to the rear silencer)? Or will I have to saw these off too? ::)
What are you actually renewing, all or part of the zorst? :-\
I've got a full cat back system kindly donated by NickW. However the other exhaust pipes are actually in good condition so I'm just (for now) going to replace the part that's bad which is the drivers' side centre silencer.... it just so happens that its that side that the fasteners are stuck in ::) the other side came out ok.
If all, then only the front flanges matter as you can get the rest off complete. If part, the middles and rear box grow to love each other and don't take kindly to being seperated. :)
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Thanks guys. Appreciate the help! :y :y :y
I'll let you know how I get on :)
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It's worth persevering with the blowtorch to get the old bolts out, because drilling the bolts out is difficult. Get the flange good and cherry red, let it cool, spray with oil and gingerly turn the bolts with a spanner. If they won't turn with modest force, get them hot again, and try again. When they turn a bit, spray with oil, turn them back and forth to work the oil in,then gradually undo them. When they are out, clean out the threads in the flange, use new stainless steel bolts and copper ease grease on reassembly.
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BG, that's a great explanation, thanks mate. so basically I only need to concern myself with the four bolts then just off the hangers and remove it as a whole unit :y :y :y
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Thanks Terry :y :y :y :y
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Concerning the back box, it will come off. I have just changed mine while changing my clutch. With the system off the car, remove the clamps (unscrew or hacksaw) and discard, then heat the length of overlapped pips with the blowtorch. Then with luck you can hammer the rear box off the pipes. If not, hacksaw the outer pipe in line with the old grooves, spray in oil, and try again. If no joy, heat it again. It will come off eventually. It's better than buying new central sections unnecessarily. It's a job I find very satisfying.
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Your probably end up drilling the bolts on the Downpipe, so for the sake of a few pennies get some Stainless Steel Nuts and Bolts to replace.
Makes it a lot easier next time for you or someone else.
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Tighten the bolts untli they shear, then drop the mid exhaust and smack the bolts out with a big hammer :y
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BG, that's a great explanation, thanks mate. so basically I only need to concern myself with the four bolts then just off the hangers and remove it as a whole unit :y :y :y
yup that's a condensed version,but with the help of your fellow noof'ers be a doodle. :y
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If you have oxyacetylene, then use it FIRST. Get all of each bolt and the nut/flange red hot, and let it cool. Do this at least twice. Then try and undo the bolt while it is still warm. This is much more effective than any penetrating fluid. You may still snap the bolt, but it is much more likely to be flush which makes drilling it easier. An experienced exhaust fitter will reheat the remaining part of the bolt, and then punch it out, but this does require practice!
Don't bother undoing clamps, burn them off and replace them. Angle grinder if a torch isn't handy. New clamps are so cheap it isn't worth messing about.
I hate doing exhausts,
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buy some really good hardened drill bits - you will need them..............
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Well home now.
Had fun ::)
Got the heat to them and they started to move. Great I thought. Pulled the fastener out...... well half of it ::) The other half is left in the downpipe flange. Couldn't get it out for love nor money.
Going to take it to a decent exhaust shop and see if they can get the remaining bits out and fit my new exhaust ::)
Thanks for all your help though boys. Very much appreciated :)
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Webby, are you saying one nut came off ok, but the other came out with the stud? Are we talking down pipe to manifold joint?
If so not a problem :y Simply refit using the old nut and stud (with nut still attached) :y
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Forgive the crude drawing, TA :)
(http://i1226.photobucket.com/albums/ee402/webbybear1/exhast_zpsb38439af.png) (http://s1226.photobucket.com/user/webbybear1/media/exhast_zpsb38439af.png.html)
Those stuck studs will not come out for love nor money. I tried heating them up and removing with molies. No chance :(
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Ah ok :y
Pop it in a vice and bang them out with a hammer :y They're only a push fit, albeit a rather rusty one :y
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Ah ok :y
Pop it in a vice and bang them out with a hammer :y They're only a push fit, albeit a rather rusty one :y
I was going to do that, Al. But the nuts connecting exhaust to manifold have also seized and won't come out so I cant get it out of the car :'(
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Could do it on the car, downpipes in place, just means using a smaller hammer :y
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Ok thanks TA. Will give it a go :)
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Ok thanks TA. Will give it a go :)
Make sure the down pipe is securely bolted to the gearbox bracket before you give it large :y
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Thanks mate. i'll be holding it while I get a willing volunteer to smack ;D
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Brave ;D
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Remove exhaust, get a good hard dot punch. Make sure the old bolts are flush with the flange,heat till very hot, nearly white, then put dot punch on bolt and give good solid whack, should come out. It is a two man job.
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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?
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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.
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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?
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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.
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Mine used to have bolts on it, which I simply knocked out ... hence the suggestion :y
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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?
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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.
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Very true mate. Without the heat though I don't think it's going to work any other way :'(
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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.
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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? :-\
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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 ;)
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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? :)
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Mine used to have bolts on it, which I simply knocked out ... hence the suggestion :y
That is because yours have already had the threads drilled out of the downpipe flanges.
When it left the factory the flanges were threaded.
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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
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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........
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You don't want to replace the downpipes - they contain the cats. They were £600 each side plus VAT TC in 2010. The manifold to downpipe nuts came off easily enough for me after heating.
Good luck.
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You don't want to replace the downpipes - they contain the cats. They were £600 each side plus VAT TC in 2010. The manifold to downpipe nuts came off easily enough for me after heating.
Good luck.
I wouldn't tuch the dealer for this kinda thing ;) Thanks for all ytour input :)
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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........
Thanks Andy. one of the main problems with getting the downpipe off in the first plae was the size of the nuts iirc. they weren't 16 and they weren't an imperial size we could actually get a socket on to :(
oh well.... im going to crack on this arvo while the nice weather is out and see what I get :)
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As I said in reply 33, they are a bit smaller than 16mm across flats. I used a 16mm full hexagon socket to get them off, the corners only sockets tend to round the corners. I think some plug sockets are 16mm hexagons.
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Sorry Terry, must've missed that. Thanbk you :)
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Mine used to have bolts on it, which I simply knocked out ... hence the suggestion :y
That is because yours have already had the threads drilled out of the downpipe flanges.
When it left the factory the flanges were threaded.
Must have been when the cats were replaced by TVP :-\ Genuine ones fitted when I bought it (still fitted) :y
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Yeah to be fair I think this is the original exhaust system! So it's done well. :)
Just checked my tool arsenal..... and can you believe it..... in the set of single hex sockets I bought I don't have a single hex 16mm (FFS). I'll go hellfrauds and get one.... assuming they sell them ::)
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Spark plug socket will fit the downpipe nuts
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Mine used to have bolts on it, which I simply knocked out ... hence the suggestion :y
That is because yours have already had the threads drilled out of the downpipe flanges.
When it left the factory the flanges were threaded.
Must have been when the cats were replaced by TVP :-\ Genuine ones fitted when I bought it (still fitted) :y
police spec and retail spec cats were different...
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Spark plug socket will fit the downpipe nuts
Excellent!!!! And I definitely have 1/2'' to 3/8'' adapters..... so i'll be able to use my breaker bar
Thanks Roberto Simierski! :y
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Don't go mad with the bar, webby use a constant pressure on it, gently gently, lots of squrty,stuff.
Then use nice new m10 nuts,and star washers.
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Don't go mad with the bar, webby use a constant pressure on it, gently gently, lots of squrty,stuff.
Then use nice new m10 nuts,and star washers.
Will do mate, Thanks very much! :)
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so i'll be able to use my breaker bar
Two or three extensions and a ratchet on the end is enough Steve
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so i'll be able to use my breaker bar
Two or three extensions and a ratchet on the end is enough Steve
Thanks Rob :y
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Yeah to be fair I think this is the original exhaust system! So it's done well. :)
Just checked my tool arsenal..... and can you believe it..... in the set of single hex sockets I bought I don't have a single hex 16mm (FFS). I'll go hellfrauds and get one.... assuming they sell them ::)
Umm im sure we had this discussion when doing heads and i showed you the 16mm that isnt listed as 16mm,as said spark plug socket lol......
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Yeah to be fair I think this is the original exhaust system! So it's done well. :)
Just checked my tool arsenal..... and can you believe it..... in the set of single hex sockets I bought I don't have a single hex 16mm (FFS). I'll go hellfrauds and get one.... assuming they sell them ::)
Umm im sure we had this discussion when doing heads and i showed you the 16mm that isnt listed as 16mm,as said spark plug socket lol......
lol u know me mate. stoopid ;D ;D ;D thanks mate :y