Exhaust Manifold removal and renewal HELP!!!!!

gremlyng

Hi guys,

I've got a 2003 plate 2.2 Ecotec Astra G (sri) the inlet manifold has cracked a few times and a mate who now has vanished has welded it to keep me going for a bit. Unfortunatley the time has come where the cracks have opened again! arghhhh There's no ticking this time around but lots of blowing from under the bonnet! And terrible MPG 225 miles out of £45 of petrol! I just as well be running an M3 at this rate!

I'm fairly handy with a socket set and another mate of mine who is also into working on cars has offered to help replace the manifold with me! What I'm needing to know is how easy it is to do on the side of the road? Is there enough access to get a socket down behind the engine to remove the manifold? I have ramps, socket set, Torque wrench etc...

Do I need to apply sealing compound to the new gasget when fitting the new part? We've also got a torque wrench but I don't know what it should be set at when fitting the new manifold. (I just ordered a Haynes manual off Amazon for £12 delivered so that should give me the torque settings)

I'd really appreciate any help that I can be given on this. Vauxhall are charging me £136 including vat for a new manifold, gasaget, studs & nuts I thought this was fairly reasonable.

cheers

BURT150

Re: Manifold removal and renewal HELP!!!!!

Ive got two inlet manifold sat in my garrage if you interested? no cracks and one has the egr hole blocked up?

JohnnyN

Re: Manifold removal and renewal HELP!!!!!

I'm confused? Are we talking inlet manifold (plastic) or exhaust manifold (cast iron)? Reference to your post regarding welding and blowing?? The inlet is at the front of the engine and the exhaust manifold is at the rear.

BURT150

Re: Manifold removal and renewal HELP!!!!!

I took it as its been plastic welded dunno.. . Im confused too :wtf:

gremlyng

Re: Manifold removal and renewal HELP!!!!!

My mistake, it's the exhaust manifold thats cracked. My confusion in calling it inlet manifold is becuase the guy that welded it up for me said that it might also be sucking in air which will or could be upsetting the air sensor which affects the MPG hence my confusion or lack of knowledge in calling it inlet manifold :oops: Its a 4 branch cast manifold that I'm looking for.

I'd definately be interested in getting hold of one off you BURT150 if we're talking about the same thing! What kind of money are you looking for?

Sorry for the confusion :shifty:

JohnnyN

Re: Manifold removal and renewal HELP!!!!!

Alrighty then!!!!

Exhaust manifolds are available from ebay or our classifieds on a regular basis. Its an easy change for DIY. Quite accessable from the rear and under the car. Its easier to remove the downpipe from the manifold from under. You will ideally need 2 new gaskets. Manifold to head and manifold to downpipe. These will be the new laminated steel variant.

Do not use exhaust paste before the cat. The gaskets will be sufficent.

The price from Vx does sound about right but this is a simple fix and will be much cheaper to do if you source from elsewhere.

cheers..

francav

take a look at this mate if your interested
http://cgi.ebay.co.uk/VAUXHALL-ASTRA-MK ... _500wt_975

gremlyng

Thanks Francav, I'm actually watching that manifold on ebay but I'm concerned that buying a second hand part could be a massive saving and the end of my troubles or on the other hand it could crack as it's from a 2001 car.

Johnny n whats your ebay shop called? I've looked at Courntney sport website and couldn't see anything listed at the minute. Thanks for the heads up on the paste, should I use a torque wrench on the new nuts? or is it not so important, I thought it would be essential as both the engine and manifold heat up so much. dunno..

JohnnyN

I don't have a ebay shop, lol! I was suggesting ebay or 'our' as in forum classified section. ;-)

I think that you have been unlucky with your manifold. A second hand pipe will be fine.

As for Courtenay, they used to stock the Piper 4-1 stainless steel mainfolds but do no longer supply them. Recent reports are coming back now that the Piper manifolds had poor quality welds and a good few have cracked.

Using a torque wrench is always the best option where you can especially on the head.

;-)

francav

no problem mate, good luck with it, fidly job showo..

gremlyng

Sorry Johnny n, I must be loosing it :oops:

I'll keep an eye on the classified section of this site, I'm still watching the one on ebay too, but as I said I'm a bit nervous about buying a 10 year old manifold just incase it becomes false econemy - It could end in me buying a new manifold after trying the cheaper route, then that would of course mean that there's 2 lots of gasgets etc... to buy. I'm wondering for the sake of £136 wether it's worth just buying new, all being well I intend keeping the car for a couple more years so I don't mind spending alittle.

Out of interest, what I was told about MPG dropping because of the crack in the manifold, is that true? I'd love to know what everyone else is getting to the gallon out of their 2.2 ecotec engines?

Cheers
Paul (Gremlyng)

astra22bertoneauto

If you are going to replace your exhaust manifold the invest in either having the precat removed or a 4-1 manifold (and remove precat). Ive had 3 manifolds so far!!! The price you was quoted seems ok from Vx but be warned I had to wait 3 months for mine!.

Id say if you got to replace invest a bit more in a 4-1 and get some power gains in the process!

Does everyone agree?

JohnnyN

4-1 are few and far between since the Piper. Other brands are available but also come with a large price tag. Thorney were supplying manifolds and Chris Tullet were too IIRC. Both excellent manifolds. The dbilas cast manifolds are available from Regal but they are very heavy and the order time is long. Again, these items do appear on eBay from time to time.

adamjmb

Hi mate just letting you know i have a standard exhaust mani, you can have it for £30 collected from me16 or posted for a bit more, comes with downpipe gasket but you still need the gasket between the manifold and engine. all details etc. are in the classified bit.

if you wanted an upgrade you can sight tight and wait for a second hand 4-1 like a piper or something but they really are few and far between.. as for new manifolds, you can get one from http://www.christullettexhausts.com/ for £500 your looking at a 2 week waiting time for them to make one. but they are very very good.

poundy

JohnnyN said:
4-1 are few and far between since the Piper. Other brands are available but also come with a large price tag. Thorney were supplying manifolds and Chris Tullet were too IIRC. Both excellent manifolds. The dbilas cast manifolds are available from Regal but they are very heavy and the order time is long. Again, these items do appear on eBay from time to time.

IVE GOT A STANDARD ONE IF YOU WANT IT??? YOUR WELCOME TO IT IF YOU WANT IT.

SORRY ABOUT CAP LETTERS I COULDNT BE BOTHERED TO TYPE IT ALL OUT AGAIN LOL

JohnnyN

adamjmb said:
Hi mate just letting you know i have a standard exhaust mani, you can have it for £30 collected from me16 or posted for a bit more, comes with downpipe gasket but you still need the gasket between the manifold and engine. all details etc. are in the classified bit.

if you wanted an upgrade you can sight tight and wait for a second hand 4-1 like a piper or something but they really are few and far between.. as for new manifolds, you can get one from http://www.christullettexhausts.com/ for £500 your looking at a 2 week waiting time for them to make one. but they are very very good.

:thumbup:

gremlyng

Wow guys thanks for all the replies and your advice and help etc.... :thumbup:

Ok where do I start lol I'd be happy to buy a standard manifold from anyone willing to part with one, so thank to 'Adamjmb' and 'Poundy' How do I go about this? how much do you want for yours Poundy?

This might sound a bit cheeky, but I wondering which one is in the best condition? I'm based in South Wales but I'd also be happy to pay for postage etc..

I think the idea of a 4-1 manifold sounds really good but I am on a tight budget to be honest. Out of interest does the 4-1 give that much more bhp to warrant spending like £500?

Whats the score with removing the pre-cat? Can this be done using the standard manifold? What would be the gains?

Should I PM you Poundy and Adamjmb?

Cheers
Paul (Gremlyng) :thumbup: :thumbup: :thumbup:

francav

your pre-cat is in top of your down pipe, you need to drill round the edges to get it out, there is a post on here about it, just use the search bar to find it mate.

gremlyng

Thanks Francav, other than the change of exhaust note what are the gains is there Any extra power?

Cheers
Paul

vocky

precat removal power gains can be anything from 2 - 8 bhp depending on other mods etc

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