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[terry paget]

X84GNB 2000 2.5 petrol manual estate
Have finally got manifold off - thanks to all for help and advice.
I thought manifold was cracked, Chris Gixer thought fault was blown gasket. Either way it was noisy and getting noisier. Pictures follow. I think Chris was right, but I have also found a crack underneath the manifold. It looks as though there was a blow at the top and back of the manifold/gasket. I have bought a good manifold off e-bay. Clearly I need a new head to manifold gasket and a manifold to downpipe gasket. I do not think the head is 'burned'. Should I clean it with steel wool to make sure? The studs came out with the nuts on them. Should I buy new studs and nuts? Have you any more advice for me? I have not done this job before on a V6.

Pictures follow. First two are of manifold and gasket showing where blowing; third shows crack

[img http://"https://www.dropbox.com/s/cxys6v12aia38ob/DSCF2310.jpg"]http://[/img]

[img http://"https://www.dropbox.com/s/e7vrh28lo9ubymu/DSCF2313.jpg"][/img]

[img http://"https://www.dropbox.com/s/dvybgl3z6r8mahd/DSCF2315.jpg"][/img]

[dbug]

Here's your pics mate







HTH

[Marks DTM Calib]

Its cracked and has also been blowing at the rear.

New gaskets.

New studs is dependent on how bad the old ones are, you should ensure the studs are in the head before fitting the manifold and then the nuts screw onto the studs, failure to do this could strip the threads in the alloy head.

[sjc]

^wot he said.  Definitely screw the studs into the head without the nuts on or you risk doing serious damage as Mark has said.

[amba]

All my studs came out either with the nuts attached or by removal after manifold was removed.

I was not in any hurry to do the job again so decided for the cost involved to by new stads and copper helicoiled nuts direct from VX.New genuine GM multilayer gasket and then torqued nuts up in the correct sequence and you should be fine.

I also bought new copper helicoiled nuts for the downpipe studes after giving the treads a good clean up with die set to be sure all would tighten up properly along with correct gasket for downpipe to manifold seal.

Other than that its just a matter of putting it all back together,although refitting is quicker as you now know the sequence and how to get at the bits .

[Gaffers]

I hope you got a replacement manifold too........

[cem_devecioglu]

I have used 2 types of manifold gaskets ..  both gm.. but only one is sheet metal .. which has a longer life..

[chrisgixer]

Would metal 3.2 gaskets be better? Don't know if they would fit..? Or indeed, is it worth fitting 3.2 manifolds? (If 3.0 un available maybe)
I was going to suggest welding the crack, but would the manifold distort in the process?

Defo blowing and cracked though. So we where both right


Sorry Terry. More questions than answers. I've experienced the symptoms, but not done the repair.

Interesting notes on the studs.

[terry paget]

Would metal 3.2 gaskets be better? Don't know if they would fit..? Or indeed, is it worth fitting 3.2 manifolds? (If 3.0 un available maybe)
I was going to suggest welding the crack, but would the manifold distort in the process?

Defo blowing and cracked though. So we where both right


Sorry Terry. More questions than answers. I've experienced the symptoms, but not done the repair.

Interesting notes on the studs.

Thanks for the thoughts Chris. My 3.2 does not has exhaust has recirculation, whereas the 2.5 has, so I presume the manifolds and gaskets are not interchangeable.
 I have had cracks welded up on 2 litre Omegas only to have them crack again at the same places.
Yes, we were both right. That explains why it was so noisy.
AS you may have read on other threads, I have made hard work of this job. Access is so difficult on these V6 engines.I have yet to reassemble it. When I have done so I shall have a celebration.
 

[Marks DTM Calib]

I have used 2 types of manifold gaskets ..  both gm.. but only one is sheet metal .. which has a longer life..

Here the non metal multilayer part was superseeded as a spare in the mid 90's.....although for some stupid reason they kept fitting it at the factory!

[Marks DTM Calib]

Would metal 3.2 gaskets be better? Don't know if they would fit..? Or indeed, is it worth fitting 3.2 manifolds? (If 3.0 un available maybe)
I was going to suggest welding the crack, but would the manifold distort in the process?

Defo blowing and cracked though. So we where both right


Sorry Terry. More questions than answers. I've experienced the symptoms, but not done the repair.

Interesting notes on the studs.

The 2.6/3.2 is a better manifold and should flow better to (it does fit) but the gaskets are not interchangeable.

Welding cast iron is an art form, not easy and you need to drilling the crack ends to stop spreading first (which many dont bother with)

[sjc]

Since you only have one side off, there is no point putting on a 2.6/3.2 manifold because you will have an imbalance of course. You will also need to use a 2.5/3.0 gasket cos you'll have the SAI system.

If you were doing both sides, I'd say go for the 3.2 manifolds and gaskets and bin the SAI system and EGR valve completely.

[omegod]

Got a pair of 3.2/2.6 manifolds here if you decide to bite the bullet , don't envy you though , manifolds are a nightmare! well done for getting this far

[sjc]

Got a pair of 3.2/2.6 manifolds here if you decide to bite the bullet , don't envy you though , manifolds are a nightmare! well done for getting this far

Yeah, not a task I'd like to try with the engine in the car - so glad I did the conversion to 3.2 manifolds before the engine went in!

[Marks DTM Calib]

Drivers side is not hard to do, three-four hour ish job