Omega Owners Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Search the maintenance guides for answers to 99.999% of Omega questions

Pages: 1 2 [All]   Go Down

Author Topic: Exhaust removal back section what usually gives grief?  (Read 818 times)

0 Members and 1 Guest are viewing this topic.

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Exhaust removal back section what usually gives grief?
« on: 17 January 2018, 07:30:05 »

Going to be changing rear centre sections and back box, just wondering what surprises i'm likely to experience when removing. Obviously not caring about join between back box and centre sections just when it gets to join to front of exhaust. Is the next part of exhaust the cats and studs likey to break?

Cheers

Andrew
Logged

BazaJT

  • Omega Baron
  • ******
  • Offline Offline
  • Gender: Male
  • SLady bitshorpe N.Lincs.
  • Posts: 4314
    • Omega 3 litre Elite
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #1 on: 17 January 2018, 08:00:07 »

When I did mine recently one of the centre pipes had rotted through just before the back box so when that was out of the way I hacksawed through the other one.The cat bolts needed lots of heat but even then one still sheared off and needed drilling out I  replaced them all with nuts/bolts.
Logged

Nick W

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 5767
    • 3.0l Elite estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #2 on: 17 January 2018, 08:02:05 »

The issue is whether the centre section to cat bolts undo. If you have to drill them out, that can take some time. If they've been replaced before then you can just cut them off.
Then it's a quick slice through the rubbers and gravity drops everything to the floor.
5 minutes maximum if it goes well.
Logged

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #3 on: 17 January 2018, 10:47:04 »

Cool thanks for advice, will check cat to centre section bolts for rot and give some penetrating fluid. Got a loan of a ramp to do job so want to make sure i dont end up with a problem while doing it.
Logged

ajsphead

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • North Somerset
  • Posts: 367
    • Omega 2.2 DTi estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #4 on: 18 January 2018, 07:32:57 »

Getting the exhaust apart is one thing. the rust on the floor pan above the back box that you'll discover may be something else.
Logged

steve6367

  • Omega Knight
  • *****
  • Online Online
  • Gender: Male
  • Posts: 1596
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #5 on: 18 January 2018, 07:41:59 »

Ir you have GM rubbers on there, don't slice them - remove and reuse - much better than those that come with the cheap replacement exhausts (which are otherwise excellent) and crack in short order.
Logged
2.2 CDX Estate (broken), 2.5 CD Salon, 2.5 CD Estate LPG

DrAndyB

  • Senior Member
  • ****
  • Offline Offline
  • Gender: Male
  • Cheshire
  • Posts: 617
    • 2.5 V6 CDX Manual (MFL)
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #6 on: 20 January 2018, 11:46:12 »

Make sure you have a couple of drill bits ready  ;)

I was going to do mine, but local garage offers 15 to fit my new one  :y  Glad I snatched their arm off took them up on their offer as one out the two on each pipe by cat was seized.

If you have a ramp, then all should be OK, but yes as already mentioned try to use the existing rubbers if GM originals.

I got an ETS 3.0 V6 system and love it. 
Logged

mantaray

  • Junior Member
  • **
  • Offline Offline
  • Gender: Male
  • Coventry
  • Posts: 202
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #7 on: 20 January 2018, 20:40:52 »

As said above, bolts can be a pain, but not a hard job, just give yourself plenty of time.
Logged
2.6 CDX Auto Estate,
71 Opel Manta A Series 2.5 V6,  92 Kawasaki ZZR 600

TheBoy

  • Administrator
  • *********
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 95287
  • Millennium Man
    • Jaaaaaaaag
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #8 on: 21 January 2018, 11:45:14 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.
Logged
I don't tolerate bickering, and I'm always grumpy.
And Lizzie Zoom says I'm a heartless bastid...and she's absolutely correct!

terry paget

  • Omega Baron
  • ******
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 2981
    • 6 omegas all petrol & man
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #9 on: 21 January 2018, 12:06:59 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.
I have similarly made hard work of drilling out the old bolts. There clearly is a good way of doing it, garages do it with confidence, forum threads say' just drill them out'. Please advise.
Logged

Nick W

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 5767
    • 3.0l Elite estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #10 on: 21 January 2018, 15:36:29 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.
I have similarly made hard work of drilling out the old bolts. There clearly is a good way of doing it, garages do it with confidence, forum threads say' just drill them out'. Please advise.


Use good quality drill bits.
If the surface you're starting with isn't flat, make it so.
Make a heavy centre punch mark in the middle of the bolt.
Start with a 4mm bit, at the correct speed, with plenty of cutting fluid. Use oil if that's all you have.
Drill straight!
You should then be able to use an 8.5mm bit to remove what's left of the bolt.


Cheap bits, overheated or broken are the usual problem. Sometimes exhaust bolts can be really hard, which leads to trying to cut corners.
Logged

terry paget

  • Omega Baron
  • ******
  • Offline Offline
  • Gender: Male
  • Midsomer Norton Somerset
  • Posts: 2981
    • 6 omegas all petrol & man
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #11 on: 21 January 2018, 16:55:14 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.
I have similarly made hard work of drilling out the old bolts. There clearly is a good way of doing it, garages do it with confidence, forum threads say' just drill them out'. Please advise.


Use good quality drill bits.
If the surface you're starting with isn't flat, make it so.
Make a heavy centre punch mark in the middle of the bolt.
Start with a 4mm bit, at the correct speed, with plenty of cutting fluid. Use oil if that's all you have.
Drill straight!
You should then be able to use an 8.5mm bit to remove what's left of the bolt.


Cheap bits, overheated or broken are the usual problem. Sometimes exhaust bolts can be really hard, which leads to trying to cut corners.
Thanks. I used smaller starting bits, which used to break. I presume the correct speed is quite slow. I shall try it next time the need arises.
Logged

Andy B

  • Get A Life!!
  • **********
  • Offline Offline
  • Gender: Male
  • Bury Lancs
  • Posts: 35165
    • R320 TDM850 SmartRoadster
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #12 on: 21 January 2018, 19:06:09 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.

Did they come from Poundland?  ???
Logged

Nick W

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 5767
    • 3.0l Elite estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #13 on: 21 January 2018, 20:01:16 »

Thanks. I used smaller starting bits, which used to break. I presume the correct speed is quite slow. I shall try it next time the need arises.


Not really; a quick look at the required speeds suggests over 2000rpm for a 4mm bit, and about 1000 for the 8. Those are about what a 2 speed cordless drill manage. Which is handy :y
Logged

Doctor Gollum

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • In a colds and darks puddleses
  • Posts: 7918
  • If you can't eat them, join them...
    • Feetses.
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #14 on: 21 January 2018, 20:45:02 »

Alternatively, tighten the nut until it shears off, then hammer the bolt out...

Failing this, notch the flange, then knock the bolt out...

Just be mindful that using an angle grinder in a confined space under the car might result in impromptu face removal surgery :-X
« Last Edit: 21 January 2018, 20:47:14 by Doctor Gollum »
Logged
Onanists always think outside the box.

Andy B

  • Get A Life!!
  • **********
  • Offline Offline
  • Gender: Male
  • Bury Lancs
  • Posts: 35165
    • R320 TDM850 SmartRoadster
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #15 on: 21 January 2018, 21:35:32 »

Alternatively, tighten the nut until it shears off, then hammer the bolt out...

Failing this, notch the flange, then knock the bolt out...

Just be mindful that using an angle grinder in a confined space under the car might result in impromptu face removal surgery :-X

The down pipe flange is threaded &  bolts through the exhaust flange are screwed into it ..... there's nothing to hammer out, unless someone has been there before & drilled a clearance hole through both flanges & bolted them together.
« Last Edit: 21 January 2018, 21:38:05 by Andy B »
Logged

ronnyd

  • Omega Baron
  • ******
  • Offline Offline
  • Gender: Male
  • Bury St Edmunds Suffolk
  • Posts: 3547
    • 51 CDX 2.2 saloon gold
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #16 on: 21 January 2018, 22:50:53 »

Cobalt drill bits are the better ones to use, TiN coated if possible. Solid carbide are very brittle and best used on a pillar drill. bit dodgy using with a pistol drill.


Logged

johnnydog

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • East Lancashire
  • Posts: 433
    • 2.6 & 3.2 sal, 3.2 est
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #17 on: 22 January 2018, 22:47:52 »

When I last renewed the two centre pipes and back box on my 2.6, one had previously been replaced by a VX piece; the other was the original from new. The bolts came out of the original with no problem, but the bolts in the previously replaced section sheared off, leaving about 1/2" protruding.
This was the push I needed to buy a 'dogs 'dangle berries'' Rothenberger blow torch, which have great reviews, and it got the edge of the flange and sheared bolt not far from 'red'. With a bit of effort with some mole grips, and few cycles of heat, the sheared bolts came out.
It appeared that the bolts in the previous replacement may have been over tightened or 'stretched', and then sheared trying to remove them, whereas the original correctly torqued bolts came out without too much of an issue.
I replaced the bolts with original VX bolts - those on the replacement pieces I fitted were tightened sufficiently to support the exhaust and to provide a gas tight seal, but not excessively so; possibly most are probably unnecessarily over tightened on refitting which causes subsequent removal problems.
Just my experience with this particular car, and thoughts - the original fitting bolts don't need to be excessively tight; on other cars, I have drilled the sheared bolts out which is relatively difficult due to problems correctly aligning the drill itself with available space relative to the underside of the car. It was easier using heat.
Every time I am under the car, I usually just give the flange bolts a turn and then re-tighten, one at a time, just to keep them as free as possible to aid future removal.
Time will tell.
Logged
2002 3.2 Elite saloon, 2003 3.2 Elite estate, 2003 2.6 Elite saloon

TheBoy

  • Administrator
  • *********
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 95287
  • Millennium Man
    • Jaaaaaaaag
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #18 on: 23 January 2018, 17:38:50 »

Make sure you have a couple of drill bits ready  ;)
Chrisgixer and I got through 23 drill bits changing the exhaust on TBE last year.

Did they come from Poundland?  ???
Nope, reasonable quality. Most went on one bolt, that had turned to something harder than diamond ;D
Logged
I don't tolerate bickering, and I'm always grumpy.
And Lizzie Zoom says I'm a heartless bastid...and she's absolutely correct!

TheBoy

  • Administrator
  • *********
  • Offline Offline
  • Gender: Male
  • Brackley, Northants
  • Posts: 95287
  • Millennium Man
    • Jaaaaaaaag
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #19 on: 23 January 2018, 17:40:55 »

Alternatively, tighten the nut until it shears off, then hammer the bolt out...
Nope, wont work, unless its been previously drilled out

Failing this, notch the flange, then knock the bolt out...
Due to weakness of flange, you will always struggle to do it up without distorting if you do this.
Logged
I don't tolerate bickering, and I'm always grumpy.
And Lizzie Zoom says I'm a heartless bastid...and she's absolutely correct!

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #20 on: 24 January 2018, 22:32:54 »

What size/length of nuts/bolts we looking at if i need them, and is that 3 per side, 6 in total?
Logged

Nick W

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 5767
    • 3.0l Elite estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #21 on: 24 January 2018, 22:50:18 »

They're M8. About 25mm long should be enough to go through both flanges and washers. Plain nuts are good enough.


You need 2 per side.


That's about 1 worth of hardware if you buy it individually.
Logged

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #22 on: 25 January 2018, 07:54:39 »

They're M8. About 25mm long should be enough to go through both flanges and washers. Plain nuts are good enough.


You need 2 per side.


That's about 1 worth of hardware if you buy it individually.

Thanks, think i've a pile of new ones lying in my garage. what other nut should i be using, nut and washer not suitable?
Logged

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #23 on: 06 February 2018, 22:44:38 »

So tonight I got under the car with the aid of my trusty drive on ramps (reverse on this time) and without much effort pulled the backbox off and the join was dust so never had to undo the clamps. Might try and salvage the clamps, but if not will try kwik fix for a fix!

Pulled both pipes from the middle section silencer as weakened by rust. Then decided to go for the meat and potatoes bit, the 2 bolts on each middle section to cat. With a little hindsight I think I should not have been so hasty because I just put a 13mm spanner and extended it with the closed end of another and all the nut heads sheared off.

Now got to get the studs out 4 of them boo hoo!

All that is left is the rubbers holding up the middle section, and there is a double clamp thing between the two pipes, the nuts look "weathered" so will be another cut off job I think or hammer a smaller socket on and heat.
Logged

robson

  • Omega Knight
  • *****
  • Offline Offline
  • Gender: Male
  • Nr Ashford Kent
  • Posts: 1494
    • 2.6 facelift 2003
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #24 on: 07 February 2018, 09:28:58 »

When I replaced mine I purchased system from eternal and got my local garage to fit it. Fitting cost was minimal and a lot of agro saved  :y
Logged

Nick W

  • Omega Lord
  • *******
  • Offline Offline
  • Gender: Male
  • Chatham, Kent
  • Posts: 5767
    • 3.0l Elite estate
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #25 on: 07 February 2018, 10:05:33 »

You're making a meal out if it; if you remove the bolts holding it to the cat, and unhook the rubber hangers the entire system will fall to the floor.


You then fit the new parts, starting at the cats, hanging it as you go. If the cat bolts aren't an issue it's a 45 minute job, working solo in the street.
Logged

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #26 on: 07 February 2018, 10:43:58 »

You're making a meal out if it; if you remove the bolts holding it to the cat, and unhook the rubber hangers the entire system will fall to the floor.


You then fit the new parts, starting at the cats, hanging it as you go. If the cat bolts aren't an issue it's a 45 minute job, working solo in the street.

Yep i usually do that with exhausts but i will put jack on it and undo rubbers and then drop it
Logged

grifter

  • Intermediate Member
  • ***
  • Offline Offline
  • Gender: Male
  • Paisley, Scotland
  • Posts: 391
  • Omega 2.6 owner
    • Omega 2.6
    • View Profile
Re: Exhaust removal back section what usually gives grief?
« Reply #27 on: 11 February 2018, 17:44:28 »

As I suspected I had to drill out the 2 bolts on both sides. Started out with a pack of silverline cobolt drills and used smallest to start a pilot hole. One of the holes was a bit offset, due to not getting the pilot started exactly in the middle, so the hole was getting bigger towards the pipe to flange section, and it would have worked out that the bolt head would have been resting on the flange to pipe weld join when I started tightening, so, after making a big ding in the remaining bit of thread with a chisel, had to drill the remaining thread with drill pointing up towards floor then grind it away with the side of the drill. Eventually got to a point where the bolt head is sitting flat on the flange face not jammed on to the weld join.

Everything looks like it's about ready to be assembled up; I just need another 54mm clamp for back box, and another 48mm clamp for the long bracket that holds the 2 centre sections in check.

Logged
Pages: 1 2 [All]   Go Up
 

Page created in 0.106 seconds with 18 queries.