Rusted Manifold Connection

911gh · 21 Oct 2017

Hi all, upon opening pandora's box and looking under my car for the first time I can see that the connection between the block and the two manifolds are rusted and corroded. This includes everything from the bolts to the mounting brackets that are around that area as well.

I'm aware that I'm going to need to replace both manifolds and that it's going to be a fairly costly procedure due to the bolts likely snapping. No garages will give me a firm quote as they don't know how much trouble the bolts will give them. Has anyone had experience doing this, if so how much did it end up costing?

Is there anything else worth replacing during this procedure? I'm pretty happy with the sound of the car for now, I've got PSE and 1.25" gundo hack but if there is anything else in that area that could be swapped out at the same time I'd love to know! It seems as though swapping the whole exhaust system out for a stainless system might not be too much more expensive (I could be vastly wrong).

Thanks!

Alex · 21 Oct 2017

Don't mess with the manifolds unless they're leaking. Budget around £500 - £1k to have them removed and new bolts fitted.

Worst job ever!!!

Phil 997 · 21 Oct 2017

Who ever you use make sure they can rebore the broken bolts , its a bitch of a job and in most cases some if not all break , there are bolts on here for sale in titanium ,I would be doing that while they are off ,also considering the cost of a set of stainless equal length headers it would make sense to do that , it will improve the note slightly but means in the future should you decide to change the cats and boxes to stainless its a much easier job. :thumb:

TonyC911 · 21 Oct 2017

After my 111 point inspection at my local OPC, they reported;

Exhaust - triangle fixings corroded - Requires removing with heat new gaskets, nuts and bolts

Is this the same problem you have?

Alex · 21 Oct 2017

No. What you have is this:

481544d1287296607-the-joy-of-removing-a-rusted-exhaust-img_4248-800.jpg

What's being discussed is this:

TonyC911 · 21 Oct 2017

Thanks Alex, that makes sense. I wondered why the repair was relatively cheap, clearly the headers would require more intricate work!

Ishay · 21 Oct 2017

This is one of those times when a highly relevant thread pops up. My turbo's sat at OPC Silverstone with a leaky manifold gasket failing the MOT. Waiting to hear how bad the bolts will be. Agreed a price for that and the 'works' of a 4 year overhaul anyway though

Scholester · 22 Oct 2017

I did this job myself as a preventative measusure and thankfully none of the bolts snapped!
Yes, it is a pig of a job and it could have ended up with me having to trailor the car to have have engineering work carried out if I had not been so lucky.
I think lower miles helped me but I am not sure I would want to do it again in all honesty.

maldren · 22 Oct 2017

As Alex says and the standard repair is to heat then up with Oxy Acetylene and knock them out with a hammer then replace with stainless. Not really a DIY job, use an OPC/Indy that has done it before.

911gh · 22 Oct 2017

Ok thanks a lot for all replies info.

It seems as though it's going to need full new manifolds/headers as it's not just the bolts that are rusted but the flat metal connection that the bolts are attached to. The rest of the manifold is absolutely fine, just the rusted plate but as they are attached, I assume the whole part has to go.

I'm fairly local to Design911 who have worked on the car before and seem fairly well versed on this operation.

I'm now deciding on the stainless manifold as a replacement. Two aftermarket headers seem to be made by DesignTek or Eurocup GT - is there any discernible difference between the two brands? The Eurocup version seems to be about £250 cheaper.

Thanks again for the help.

Alex · 22 Oct 2017

From what you've described, that's perfectly normal and will stay in that state for at least another 5 years. I did mine on my 996 as the gasket between them and the blocks were blowing. I thought to ease the blow, I'll buy some brand new stainless ones off eBay. They were £120 and 3 years later are still fine.

Save your money and leave well alone........unless you're thinking of keeping it another 10 years, but no doubt you'll need a rebuild before then, at which point, they'll do the job as part of the rebuild.

Alex · 22 Oct 2017

These from Germany:

http://www.gm-carsolution.de/PORSCHE/Faecherkruemmer-387/Faecherkruemmer-Porsche-996-997-911.html

or similar and cheaper from eBay:

http://www.ebay.co.uk/itm/STAINLESS...7511150?fits=Plat_Gen:996&hash=item5d398d29ee

seeforez · 22 Oct 2017

i did this as preventative maintenance and i still have the bits of metal in my eyes to remind me not to try any preventative maintenance again....can be a **** of a job especially on axle stands

wasz · 23 Oct 2017

Run away leave well alone and try to put it out of your mind.

My manifold does not leak after 132k miles, 18 years and the car is used throughout the year.

The manifold bolts look like amorphous rusted blobs but there are no leaks.

I am however, saving up for some new drill bits and will hopefully be able to borrow a jig when the time comes if it ever does in my ownership.

Scholester · 31 Dec 2017

I used the Ebay headers (Turbo version) that Alex posted the link to and the fit is excellent.
Just make sure that you consign the bolts/nuts they supply to the bin. I used titanium at the block and stainless at the Turbo.

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