Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: geoffr70 on 29 August 2010, 23:50:34
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Hello, I finished putting the car back together tonight after replacing my exhaust manifold gasket (drivers side). This job was a nightmare. I never ever want to do it again. Anyway, I fired her up, she wasn't running too well as she'd been stood for a few days, the battery was flat, she was cold, and the fuel was completely drained from the injector assembly.
Pulled down the street, and it was like driving a completely different car. She was lovely and smooth and quiet. Much better to drive, alot torquier and so much more quiet. There was a vac pipe that I must've missed last time so I connected it and the brakes were alot better. The handling was so much better, don't ask me how or why?!?! To sum up it was like a new car. I took her for a 20 min drive then I heard the terrible gas leak sound again. I'm devastated. It took me the best part of 20 hours over 2 days to do this and it's back to square one, only not quite as bad. I used a VX gasket, new nuts and studs, and all torqued up correctly to 20nm. i used a new gasket on downpipe and torqued the nuts to 20nm. All mating faces were cleaned up and there were no cracks in manifold.
Any ideas? Could it just be the downpipe? I hope so. As it happens the old gasket didn't look that bad, or as if it was leaking anyway.
PLease help someone! Thanks
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Hello, I finished putting the car back together tonight after replacing my exhaust manifold gasket (drivers side). This job was a nightmare. I never ever want to do it again. Anyway, I fired her up, she wasn't running too well as she'd been stood for a few days, the battery was flat, she was cold, and the fuel was completely drained from the injector assembly.
Pulled down the street, and it was like driving a completely different car. She was lovely and smooth and quiet. Much better to drive, alot torquier and so much more quiet. There was a vac pipe that I must've missed last time so I connected it and the brakes were alot better. The handling was so much better, don't ask me how or why?!?! To sum up it was like a new car. I took her for a 20 min drive then I heard the terrible gas leak sound again. I'm devastated. It took me the best part of 20 hours over 2 days to do this and it's back to square one, only not quite as bad. I used a VX gasket, new nuts and studs, and all torqued up correctly to 20nm. i used a new gasket on downpipe and torqued the nuts to 20nm. All mating faces were cleaned up and there were no cracks in manifold.
Any ideas? Could it just be the downpipe? I hope so. As it happens the old gasket didn't look that bad, or as if it was leaking anyway.
PLease help someone! Thanks
I hope so too Geoff. You must be pretty down after that.
Is it possible that some vacuum pipe has blown off, some connector has came loose.
Wish I could be of more help. :'( :'( :'(
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I am also gutted for you,geoffr70 especially as it first sounded like you had sorted it out.
Are you sure it is nothing to do with the egr or the flexiy pipe that connects to the manifold on the drivers side.I am trying to think of words of encouragement for you,but I hope a decnt nights sleep and a fresh check may juts turn up a simple fix for you..well lets hope so.
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Thanks Guys, I'm going to check them all again now, I made a few mistakes on the make up as I was in a rush and wanted to get finished, and had to redo them! Hopefully it'll be something daft that I've missed! If not I'll have to do it all again! IMO abs ecu like a walk in the park compared to this! Can anyone tell me why I bought a v6?
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Can anyone tell me why I bought a v6?
Because it has almost the right number of cylinders (it's only missing 2, not 4)? ;)
Sorry.. I know that doesn't help!
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Pulled down the street, and it was like driving a completely different car. She was lovely and smooth and quiet.[/quote]
That's why :y
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Are you sure it is nothing to do with the egr or the flexiy pipe that connects to the manifold on the drivers side.
I do have the memory of a gold fish but I don't remember a flexi joint on the manifold from when I removed the cats from my 3.0?
I'm wondering if 20 n.m. may be the problem, it doesn't seem like very much to me...
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Indeed, that's .. 15lb/ft? That's not even one white knuckle ;)
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After having a nights sleep and thinking logically about this I have found the problem, and know how to solve it quickly and easily! When disassembling secondary air injection I noticed a hole in the hose that bridges two metal pipes next to o/s bank. The hose is about 3 inches long. I didn't think anything of it, but had some hose lying about so cut it and replaced it on reassembly. Once everything was reassembled, there was something burning instantly, and giving off smoke. This stopped after 30 seconds and I assumed it was residue from where I had cleaned coolant. So as stated before, car ok twenty mins then back to normal blowing. On inspection I can see that the new piece of pipe has burnt through, which is the source of the noise. Which is why the original manifold gasket was in good condition - it didn't need replacing! How stupid, and annoyed do I feel now! What I don't understand is how did this pipe burn through instantly, yet it was cool to touch enough to put my hand over it (with engine running) to confirm that was the source of the noise?
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After having a nights sleep and thinking logically about this I have found the problem, and know how to solve it quickly and easily! When disassembling secondary air injection I noticed a hole in the hose that bridges two metal pipes next to o/s bank. The hose is about 3 inches long. I didn't think anything of it, but had some hose lying about so cut it and replaced it on reassembly. Once everything was reassembled, there was something burning instantly, and giving off smoke. This stopped after 30 seconds and I assumed it was residue from where I had cleaned coolant. So as stated before, car ok twenty mins then back to normal blowing. On inspection I can see that the new piece of pipe has burnt through, which is the source of the noise. Which is why the original manifold gasket was in good condition - it didn't need replacing! How stupid, and annoyed do I feel now! What I don't understand is how did this pipe burn through instantly, yet it was cool to touch enough to put my hand over it (with engine running) to confirm that was the source of the noise?
That tells a story....you have either a blocked exhaust or cat as they should not be exposed to hot gases under normal operation.
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After having a nights sleep and thinking logically about this I have found the problem, and know how to solve it quickly and easily! When disassembling secondary air injection I noticed a hole in the hose that bridges two metal pipes next to o/s bank. The hose is about 3 inches long. I didn't think anything of it, but had some hose lying about so cut it and replaced it on reassembly. Once everything was reassembled, there was something burning instantly, and giving off smoke. This stopped after 30 seconds and I assumed it was residue from where I had cleaned coolant. So as stated before, car ok twenty mins then back to normal blowing. On inspection I can see that the new piece of pipe has burnt through, which is the source of the noise. Which is why the original manifold gasket was in good condition - it didn't need replacing! How stupid, and annoyed do I feel now! What I don't understand is how did this pipe burn through instantly, yet it was cool to touch enough to put my hand over it (with engine running) to confirm that was the source of the noise?
That tells a story....you have either a blocked exhaust or cat as they should not be exposed to hot gases under normal operation.
You don't think it is a faulty non return valve in one of the stainless steel pipes then?
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After having a nights sleep and thinking logically about this I have found the problem, and know how to solve it quickly and easily! When disassembling secondary air injection I noticed a hole in the hose that bridges two metal pipes next to o/s bank. The hose is about 3 inches long. I didn't think anything of it, but had some hose lying about so cut it and replaced it on reassembly. Once everything was reassembled, there was something burning instantly, and giving off smoke. This stopped after 30 seconds and I assumed it was residue from where I had cleaned coolant. So as stated before, car ok twenty mins then back to normal blowing. On inspection I can see that the new piece of pipe has burnt through, which is the source of the noise. Which is why the original manifold gasket was in good condition - it didn't need replacing! How stupid, and annoyed do I feel now! What I don't understand is how did this pipe burn through instantly, yet it was cool to touch enough to put my hand over it (with engine running) to confirm that was the source of the noise?
That tells a story....you have either a blocked exhaust or cat as they should not be exposed to hot gases under normal operation.
You don't think it is a faulty non return valve in one of the stainless steel pipes then?
There are no one way valves in the steel pipes, the only one is where the rubber hose to the vac operated valve on the rad connects.
If you get an exhaust blockage then the gas pressure increases and it travels along the steel pipes to the opposite banks manifold exposing the rubber couplings to heat....they then melt and phut phut phut...
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If your Omega has the standard exhaust, it should have separate pipes from engine through to tail pipe.
Check the pressure at each pipe and compare them. They should be as close to equal as possible.
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Glad you have got it sorted out,geoffr70..amazing what a clear head and a nights sleep can solve.
Pity this pipe is not my problem but it is definitaly the nearside manifold gasket..when started from cold and block off the tailpipe you can feel the exhaust escaping from the manifold with your hand.Seems the only sound solution is to have the heads taken off and both gaskets renewed..this is the remedy advised by our resident mechanical wizard.
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Glad you have got it sorted out,geoffr70..amazing what a clear head and a nights sleep can solve.
Pity this pipe is not my problem but it is definitaly the nearside manifold gasket..when started from cold and block off the tailpipe you can feel the exhaust escaping from the manifold with your hand.Seems the only sound solution is to have the heads taken off and both gaskets renewed..this is the remedy advised by our resident mechanical wizard.
You definitely do NOT need to remove the heads! :-/
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The removal of the heads was on the advise of a well respected forum member.
I had read that the nearside gasket could be done ,with difficulty and very limited access,without the head being removed,but the feeling was the potential risk of a stud snapping and then the need to remove head anyway outwayed the quick fix.
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The removal of the heads was on the advise of a well respected forum member.
I had read that the nearside gasket could be done ,with difficulty and very limited access,without the head being removed,but the feeling was the potential risk of a stud snapping and then the need to remove head anyway outwayed the quick fix.
Whilst I dont want to step on anyones toes, why remove the head IF you dont have to. You are just opening up potential for more problems.
The Head is aluminum, the studs are steel. If they snap, a stud extractor can usually be used. If not, remove the head for drilling. I have done a huge amount of research on this subject, as mine needs doing (being done Thursday this week) and nobody, but nobody has suggested removing the heads to do the work unless absolutely necessary. :y
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The removal of the heads was on the advise of a well respected forum member.
I had read that the nearside gasket could be done ,with difficulty and very limited access,without the head being removed,but the feeling was the potential risk of a stud snapping and then the need to remove head anyway outwayed the quick fix.
Whilst I dont want to step on anyones toes, why remove the head IF you dont have to. You are just opening up potential for more problems.
The Head is aluminum, the studs are steel. If they snap, a stud extractor can usually be used. If not, remove the head for drilling. I have done a huge amount of research on this subject, as mine needs doing (being done Thursday this week) and nobody, but nobody has suggested removing the heads to do the work unless absolutely necessary. :y
Agreed.
Not that hard to do nearside, just heavy on the arms and back as it all has to be done from below
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Suppose it was the preference of the mechanic then ?
Now I will have another think over my next step..gasket does need doing and when costing up the parts needed it works out at less than £40=00,compared to much/much more to remove the heads.
I had once thought about having a go at this myself but lots of potential nightmares seem to crop up..although do feel happier when read that the bolts snapping off seems to be the minority of cases.
Assume it is easier on axle stand than ramp ?
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I was expecting some comments about changing the gasket when there was no need to! During disassembly, the hole in the rubber hose on secondary air injection should've been a giveaway - if only I knew what it was for at the time!
Thinking about it, the smoke on initial startup must be unrelated, but the noise appearing after 20 mins must be the amount of time it's taken for the hot gases to finally breach the rubber and make the hole. It has also melted the rubber under the quick connectors connecting to metal pipe, compromising integrity of connection, nevermind the hole!
Right, it has the standard exhaust, except a big twin 'D' shaped stainless steel tipped back box, embossed with Irmscher. I'm assuming this is factory fit, or aftermarket OEM, I didn't ask when I bought the car, but the box doesn't fit exactly 100% right in the cutout in rear bumper. With car running, but not hot, I can feel gases being forced out the secondary air injection pipe, from o/s bank back towards the front of car (this is wrong I take it), although I am able to cover the hole with my finger to stop gases without pressure being to great on my finger.
Is the rubber pipe on secondary air injection a high heat hose, or I take it it must just be able to stand radiated heat from the engine bay? Motorfactors just gave me a scared kid look and didn't know what i was talking about! I've got flexible copper pipe from B and Q that I was going to use to bridge the gap, but from what MDTM says, it sounds like i must need to investigate possibility of exhaust blockage before going down this route. Which comes onto my next question! Is there an easier way, apart from disconnecting an exhaust section at a time to measure pressure to try and locate the blockage? I don't think so but I hope so!
Incidentally, brakes seem worse again with pipe with hole in - might be something to do with vacuum?!? I don't know.
On the plus side i took some photos when doing this so will attempt at making some sort of guide.
Line up if you want to call me a */'"-$!^ for changing exhaust manifold when I didn't need to! I think 20 nm for nuts is what it said in Haynes, although that goes to T mines a W, but can't be much difference?
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I was expecting some comments about changing the gasket when there was no need to!
We are to polite for that. Anyway I think you've suffered enough.
:y
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...Line up if you want to call me a */'"-$!^ for changing exhaust manifold when I didn't need to!...
I doubt there's many of us who've never misdiagnosed a fault and spent time and/or money fixing the wrong thing. :)
Good luck with sorting out the residual problem. Should be much easier than what you've done as a 'warm-up'. :y
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On the plus side I fitted a new HBV in the process, and got a whole load of lovely new coolant. I'm treating her to a oil change, and getting her a sister. A nice 3.0 litre MV6 manual saloon f/l, 2 owner, low miles, in Ferrero Roche colour. I'm spoiling her!
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One option is to simply block the air injection off......its not really required.
Then, sooner or later, the side with the blockage will 'reveal' itself ;D
Do the cats rattle if tapped?
And what state are the two centre silencers in and what noise do they make when thumped?
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I should add, its not high temp hose as it never gets exhaust gases through it under normal operating conditions
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One option is to simply block the air injection off......its not really required.
Then, sooner or later, the side with the blockage will 'reveal' itself ;D
Do the cats rattle if tapped?
And what state are the two centre silencers in and what noise do they make when thumped?
Thanks Marks DTM Calibration! Sorry to be a pest! What is the best method for blocking 2ndary air injection off? Can this be done with pipe still on manifold? Do you have to do it on both banks, or can just one be done?
I'm intrigued how the blockage will reveal itself?!?!
I used to have a rattle on exhaust, I've got some big jubilee clips but haven't fitted them as rattle has gone, and i assumed it was heatshield on downpipe. It seemed to disappear when warm.
Centre silencers and Cats appear OK from observation when under car. i didn't take too much notice, only visual. O/S cat didn't rattle when pulling downpipe off manifold, don't know about n/s.
Thanks
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Any chance of a photo that pinpoints where this pipe is, in case it is my problem......
I bet it isn't though :(
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Hi dad1uk, I took some photo's during the job, and one in particular of the breached hose while still attached to the final SAI pipe before it goes to manifold, but off the car. I'll sort my camera out and have a look at uploading a few pics tomorrow.
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The removal of the heads was on the advise of a well respected forum member.
I had read that the nearside gasket could be done ,with difficulty and very limited access,without the head being removed,but the feeling was the potential risk of a stud snapping and then the need to remove head anyway outwayed the quick fix.
Well I've never done this job but from my ever increasing amount of time spent under car doing various jobs, I would definitely attempt the n/s manifold gasket fom beneath, without removing head.
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Must say I am become more confident about having a go at the n/side gasket myself with what I read as the costs involved for the head removal/refit is considerable even at very competitive rates,especially when it seems possible to diy the job for less than half a tank of fuel.
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get yourself under and weigh up whether or not you think you'll be able to do it. Don't forget that alot of things seem daunting and you think you won't be able to do it, but once you get going there is always a way, no matter how fiddly, it only takes a little more time, that's what I've learnt. Plus you'll get the satisfaction of having done it yourself! Then with the money saved you can treat yourself, or the car! Go for it! :y
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Hi dad1uk, I took some photo's during the job, and one in particular of the breached hose while still attached to the final SAI pipe before it goes to manifold, but off the car. I'll sort my camera out and have a look at uploading a few pics tomorrow.
Thanks Geoff :y
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(http://[IMG]http://i832.photobucket.com/albums/zz249/geoffr70/Car%20pics/PICT0073.jpg)[/img]
(http://[IMG]http://i832.photobucket.com/albums/zz249/geoffr70/Car%20pics/PICT0072.jpg)[/img]
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Hi dad1uk, got these photo's up as requested for your info and anyone else who will find them helpful.
By looking at the picture of the manifold you will be able to work out the orientation. The picture of the SAI pipe is the same orientation. Imagine you're in the V of the engine looking outward towards offside.
You can see the holes in the manifold where the two ends of the SAI pipe connect, and on the SAI pipe you can see the ends that go in. I trust you will be able to get your bearings and know exactly where this is.
The hole in the rubber pipe was actually facing downwards when on the car, so can't immediately be seen if you get your head in engine bay, or unless you put your hand down for a feel. The pipe I put on to repair it went in exactly the same place, so check yours here aswell, and don't make the same mistake I made and change the exhaust gasket when I didn't need to!
If you need anynore help just let me know. :y
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I should add when I stuck my head in engine bay to investigate source of noise (sounded blatantly obvious to be exhaust man gasket), I wasn't drawn to this other fault. There were no other indications, it sounded as if it was the gasket, but as I since found ou :'(t it wasn't.