Exhaust manifold cracked

Exhaust manifold cracked

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Discussion

ERIKM400

Original Poster:

142 posts

139 months

Sunday 6th March 2016
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Took the car out for a drive last week.
Immediately noticed a ticking sound from the engine bay when accelerating and some pops and bangs from the exhaust when idling.
Having read all the stories about exhaust manifolds made from chocolate or cheese, today I took a good look around the engine bay and, oh yes, the front exhaust manifold has cracked.
The tubes for the outer 2 cilinders are split almost their entire length!

So a couple of questions for the Noble community:
- What are my options: a friend of mine, who is an expert TIG welder suggested welding them up with an extra plate on top. But from the stories on here it seems that most repaired manifolds will just crack again.
- New stainless steel manifolds? I have been quoted 600£ per side, including all nuts, bolts, brackets and gaskets from Leon at Alunox. Does this seem reasonable? (I would love the Inconel ones but simply can not justify the cost, not even with some serious man maths thrown in).
- Should I replace both manifolds together or will the rear one be fine (looks OK as far as I can see)?
- And last but not least: can anyone advise me on how to replace the front manifold? Is this an engine out job or can it be done with the engine in the car? The turbo side of the manifold looks accessible but whaat about the engine side?

Thanks in advance.

kenloen

304 posts

144 months

Sunday 6th March 2016
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Its all down to money.....

My front manifold was welded over a year ago and has remained OK over the past 4k miles. If it goes again I will replace. Rear manifold was OK so wasn't touched. You can get the manifold off with with just the floor off and and the car raised, its a pig of a job though..

Adrian W

14,413 posts

235 months

Sunday 6th March 2016
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i think the Alunox ones are the best, I have seen the others , you can change the front without taking the under tray off, but if it were me curiosity would get the better of me, I would want a good poke about.

Blu3R

2,379 posts

206 months

Sunday 6th March 2016
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As has been said - you can replace it from underneath but it's a real pig of a job. I had my cracked manifolds chamfered, welded and plated and then sprayed with heatproof paint. They lasted approximately 2k miles and now I'm in the same situation again. At the time many owners suggested replacing them instead of welding up but I thought I knew best...
Be aware that if you do repair them and don't clean the insides of any shards or swarf you run the risk of those bits blowing off when hot and being ingested by your turbo. I made sure of mine so I was comfortable I'd be ok, but there is the risk.
The genuine Noble manifolds available these days are far better than the originals and I don't recall anyone having problems with those. As for changing both, the rear is far easier to replace than the front so if it were me and my rear one was ok, I'd wait until it fails. But that's just my opinion.

TuxMan

9,011 posts

245 months

Sunday 6th March 2016
quotequote all
The genuine Noble units are superb now .

Metalman

1,173 posts

225 months

Sunday 6th March 2016
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I'm also thinking of fitting new manifolds, any idea on the price of the noble units tux?

macky17

2,220 posts

196 months

Sunday 6th March 2016
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I believe the standard replacements are the 'Tullet' manifolds. I had my front one replaced for one of these at Bespoke just over a year ago at around £1k fitted. I left the rear alone and so far it's fine.

TuxMan

9,011 posts

245 months

Sunday 6th March 2016
quotequote all
I think they are £500 ish each . Best speak to Jetstream they normally gave them on the shelf .

coolchris

949 posts

209 months

Monday 7th March 2016
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Had a mare with Leon at Alunox plus had to wait 6 weeks to get the manifolds (one was welded wrong twice even though he had my 2 old manifolds to copy from (2.5).One of the manifolds on the 2.5 has an angle where it connects up to the turbo but twice I was supplied a manifold with a flat end(for a 3.0).The manifolds to be fair were spot on cant fault the quality but the service was poor in my opinion I would go to Jetstream.

Driven

56 posts

116 months

Monday 7th March 2016
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I have a pair of M400 manifolds sitting in a shed, waiting for a new owner. They are in good condition... PM me and I'm sure we can work something out.

ERIKM400

Original Poster:

142 posts

139 months

Monday 7th March 2016
quotequote all
Driven said:
I have a pair of M400 manifolds sitting in a shed, waiting for a new owner. They are in good condition... PM me and I'm sure we can work something out.
Just tried but your profile doesn't allow contacting you by mail :-(
Maybe you can PM me a couple of pictures of the manifolds?

Tuscanny

215 posts

133 months

Tuesday 8th March 2016
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If anyone else has manifolds I would be interested thanks.

andygtt

8,345 posts

271 months

Tuesday 8th March 2016
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I have M400 ones on the shelf, but i would still recommend you buy new Noble ones as they are much better quality.