What extras are needed to swap exhaust headers?

[stephenkirsh]

Hi all,

I need to swap my track exhaust headers to smog-compliant headers. I've not done something like this before, so I'm wondering what "extras" are needed.

Things I know about:
Manifold gasket x6
O-ring where each header meets the next exhaust piece x2

Anything else?

Also, does anybody have any good DIY videos are articles they could link?

[CTMP4me]

Originally Posted by stephenkirsh

Manifold gasket x6
O-ring where each header meets the next exhaust piece x2

That's probably enough for a West Coast car. For anything that sees winter on East Coast, I'd probably replace some of the fasteners too and get ready to break out the grinder. Practically speaking, I leave header install to pro mechanics because it's hard work and I would just spend double time on it, sweating and swearing. There is a reason why it's 3-4 hours of labor in $ even if it takes 2.

[stephenkirsh]

I'll be quite happy if it takes me 8 hours, since I've never done this before.

The headers were swapped less than 2 years ago, so that combined with it being a FL/CA car, I'm hoping I shouldn't break anything.

[rockstar93]

Overall it's a fairly straight-forward job, although I agree can be quite the pain in the ass depending on how many seized bolts you may have.

Here's a pretty good DIY guide:
https://www.billswebspace.com/BMWZ4M...stallation.htm

You've listed basically everything needed, but I was told I should do the CPV o-ring as it's common to leak and a major pain to get to normally but it's only a 3 minute job if the headers are already out.

[stephenkirsh]

Originally Posted by rockstar93

Overall it's a fairly straight-forward job, although I agree can be quite the pain in the ass depending on how many seized bolts you may have.

Here's a pretty good DIY guide:
https://www.billswebspace.com/BMWZ4M...stallation.htm

You've listed basically everything needed, but I was told I should do the CPV o-ring as it's common to leak and a major pain to get to normally but it's only a 3 minute job if the headers are already out.

This link is perfect, thanks!

What does the CPV do? I'm not familiar with it from my M54 cars. I see in the notes from the PO that it has been changed already.

[rockstar93]

Originally Posted by stephenkirsh

This link is perfect, thanks!

What does the CPV do? I'm not familiar with it from my M54 cars. I see in the notes from the PO that it has been changed already.

I believe it's basically just an oil pressure relief valve. There's a tiny o-ring inside it that tends to harden and leak. There's a bunch of aftermarket viton replacement o-rings that last much longer than OE rubber and they cost <$10. If the PO replaced it with one of those you should be good, although if they replaced it with OE I would maybe swap it again for the peace of mind while you're there.

DIY for that here. You'll see how easy it is with the headers off, but with them on you'll have a fun time.

[XMetal]

Do M54 cars have CPV? I've only heard the problem being on S54 cars

[stephenkirsh]

Originally Posted by XMetal

Do M54 cars have CPV? I've only heard the problem being on S54 cars

I have 2 M54 E46s and I've never seen or heard it mentioned anywhere, but I've seen it about 20 times already since I bought my M Coupe.