Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: hawke113a on 15 August 2011, 18:58:10
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i have a v6 2.5 and the exhaust is blowing from the manifold.i have consulted the haynes manual and it says to remove the manifold on the drivers side,i have to remove the engine or take off the head.is there any possible way to do it without been so drastic. :-/ :'(
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Copied from a post made in 2008
Re: Drivers side exhaust manifold
Reply #25 - 17. Dec 2008 at 13:16 Here are the notes I collated before I did the job on mine:
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Post 98 models should have the non-seize manifold nuts fitted
Drop the front pipe off of the manifold (two bolts accessed from under the car)
Remove the plenum and intake assembly.
Remove the scuttle cover.
Drain the coolant.
Disconnect the main stainless steel coolant pipe that runs around the drivers side head at the rear of the block (two bolts, you need to lean over the engine to reach) and remove it.
Removing the coolant pipe from the block isn't that easy - you need a long E10 socket to get past the oil pipes (and a lot of patience).
Remove the manifold heat shields. There is an extra e10 bolt on the inside of the manifold at the rear – you may find that these will shear off!!!
You also need to remove the heat shield from the exhaust manifold. The lower heat shield usually comes off with ease (only 2 or 3 E10's)
Unbolt the manifold.
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Manifold nuts are locking nuts - when new they are oval at the ends - if you get new ones make sure they give you 13mm nuts - 2.6 & 3.2 went to 10mm nuts not as good.
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Part no. Price
Exhaust downpipe nuts M10 x 2 90570845 approx £1.50 each (have helicoil insert)
Manifold gasket 24416110 £5.91
Manifold nuts x 7 11082413 £0.26 each
Manifold studs x 7 90106924 £0.45 each
Coolant pipe O-ring 9128362 £1.46
Front pipe gasket 90499289 £4.55 each (rip off)
Secondary Air Injection gaskets x 2 90467427 £0.40 each
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By MarkDTM
My approach to this job is.
Drain the coolant
Jack the car up and remove the two front pipe to manifold nuts (should be easy on yours as it uses the later helicoiled nuts) and remove the bolt that secures the front pipe to the gearbox bracket. Pop the front pipe of the manifold studs (takes a bit of wiggling and sometimes requires a foot on the centre section silencer to get it off) and then tie the front pipe to th gearbox to give it some support before putting the car back on the floor.
Strip the inlet manifolds off and place to one side, no need to remove the lower manifold for this job (which saves th pain or removing 12 thread locked bolts!).
Now disconnect the pipes to the heater matrix assembly (fast fit conenctors, press the tabs and slide the collar back, twist the connectors a few time to free them off), disconnect the vaccum pipe that goes to the bypass valve and disconnect the pipes that attach to the coolant bridge and main coolant pipe. Now remove the bypass valve and all its associated pipe work.
This gives a nice amount of space to work in.
Removal of the header tank (again easy) gives more room to work in.
Disconnect the main radiator to coolant pipe hose at the front left of the engine and disconnect the air injection rubber coupling on the left side of the engine.
Remove the bolt on the 1-3-5 bank lifting eye that secures the coolant pipe to the negin and then remove the lifting eye (single bolt again)
Now, using a short extension on a ratchet, remove the two torx bolts (think there e12 but could be wrong) that secure the coolant pipe to the back of the block, for the right hand one you might have to ease the oil cooler pipes out the way a little.
The coolant pipe should now come out (honestly, it does, takes a bit of manouvering!).
Now spray all the heatshield bolts with penetrating fluid and go and have a cuppa.
Now remove the heat shields starting with the upper one, then the air injection pipe and finaly the lower one remembering that there is a securing bolt right at the rear of the manifold to the right of the downpipe connection.
Now pop the manifold off, again shouldn't be an issue given the age of the engine as again it has the later studs.
Clean the head face well and check the manifold carefuly for cracks (it seems to be only the Police that manage to crack them from my experience) before cleaning the face of it and checking its flat, I use a belt sander to flatten them off a bit (makes cleaning easier to). I also use a tap and die to clean all the threads up.
Then re-assembly is reverse of removal, I use a small wipe of silicon (cam cover sealent or similar) on the rubber O ring for the coolant pipe just to hold it safely in place when re-fiting.
You also want to clean the rear block mating surface before re-fitting the pipe....
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are the head gaskets changed before ?
looking your cars age, from my experience I passed those stages (both manifold gaskets changed ) and then head gaskets give up.. so it would be very economical to call oof mobile mechanics and have all gaskets changed at a time..or at least having a check.. because its not an easy job..
and one more point, those metal sheet layer gaskets must be used as the others are not reliable.. they are sold seperately..
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I've done quite a few now and you don't have to remove the engine ;)
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sounds like a bugger of a job will have to wait for some sunny weather(yeah right) cheers guys
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btw its a r reg elite(98) dont know if this makes a difference
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Passenger side is a total mare and you will require the engine off its mounts and tipped to one side.
Drivers side ,whilst it is still not simple it is just a matter of unbolting lots of bits and then replacing them as with most work on the V6. The tricky and fiddley bit is getting at the coolant transfer pipe where it meets the block at the back fof the engine.You need to take off quite a few bits to get access to the securing bolts and nimble fingers.
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I've done quite a few now and you don't have to remove the engine ;)
We also dont move the heads but after experiencing those jobs, I'll better move the heads and do all (including head gaskets) at a time.. much simpler , easier and cost effective.. otherwise it will require another 2 different jobs sooner or later.. :-/
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how much would it be to have it all done????any ideas
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how much would it be to have it all done????any ideas
pm mobile mechanics.. you can find their names in genchat.. :y
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Can you please give me the TIGHTENING SEQUENCE for the 7 nuts ?
(http://i1088.photobucket.com/albums/i324/porosz23/Exhaustmanifoldgasket.jpg)
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Don,t think there is a specific sequence but I would imagine starting at F then E,B,C,G,D,A as that would then be working from the middle outwards.
Remember they only require 20nm torque but access with a torque wrench could be a challenge.
Did you have much grief getting it all apart or did you remove the heads ?
Some pictures would be usefull for others if you are able to.
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HI i worked at the plant - there is a tightening sequence - your start at B on your diagram then E & F then A & C then D & G then back to B all at 28 NM
the problem with the 13mm nuts fitted to the original engines where they pulled the manifold studs out when removed - even though they were loctited in - the later 10 mm nuts don't
i have just rebuilt a 3.2 v6 and not one stud came out - amazing !!!!!
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Grief :
Well, cylinder heads were removed, so those rusty things attached to them were crying : - Remove us too, remove us....
With the cylinder heads out, it wasn't a hard task at all.
Sequence : That sequence(i.e.B>E>F>A>C>D>G ) seems logical, though I think 28Nm is too much. Haynes says 20Nm.
As far as I know this procedure should consist of 3 stages :
1st stage : 14Nm(or so)
2nd stage : 20Nm
3rd stage : 20Nm again, just in order to double-check torque values
Studs :
I thought I'd best create studs myself, using stainless steel material. Was it a bad idea ?
Pics:
I don't think I could post here VALUABLE photographs.
A cylinder head....so what ? :O)
All right...if you insist... here you are :
(http://i1088.photobucket.com/albums/i324/porosz23/Cylhead1-1.jpg)
(http://i1088.photobucket.com/albums/i324/porosz23/Cylhead2.jpg)
Closed end cap nut (used for tightening the stud,then removed, comes off easily as the stud is tightened a bit)
(http://i1088.photobucket.com/albums/i324/porosz23/Closedendcapnut.jpg)
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Didn,t realise you had the heads all removed and cleaned,so yes..thanks for pictures but well yes ..they are 2 heads.
Can,t offer any advise about S/S tappings but understand the logic in torque sequence and values.
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28 NM is the torque that was used in the factory and as i worked for QA in the plant for 13 years i can reassure you that is the correct torque!