Exhaust manifold

Taz's Master · 06-04-2003, 09:22 AM

I have a crack (or possibly a few cracks) in my exhaust manifold. Is the manifold to head gasket reusable, or will it need replaced? Same with the gasket between the bottom and top halves of the manifold. Should I expect to take the top half through the top and the bottom from below, or both out from underneath? Will I need to remove the hard coolant line above the manifold (thus introducing me to the wonderful world of bleeding the cooling system), or if everything comes out the bottom can I leave it attached?

Porsche944 · 06-04-2003, 10:22 AM

You can leave the cooling line attached.

Before you start, get new header to head and header to CAT gaskets, new bolts/nuts/washers, new exhaust studs/nuts/washers, and a can of PB Blast or Liquid Wrench.

I heard that Saturn exhaust studs will work, and they have a neat Torqx head for easy installation.

You should be able to pull the headers out through the top.

AFJuvat · 06-04-2003, 11:19 AM

Spend the extra bucks and get new gaskets. The mylar "donuts" between the pipes can be reused if they aren't cracked.

All the above is true - penetrating oil is your friend here - broken studs are bad things.

If you are just doing headers, they can come out the top - be careful not to bend\break anything.

Anti-sieze the nuts and studs when you put everything back together.

AFJuvat

TCMdocs944 · 06-04-2003, 12:49 PM

That bastard manifold almost killed me.

studs - tedious but easy

bolt from man to cat - @#@$$%%^& @#$%%^& #$%^&&^ #$%

One bolt still remains and my Dremel will be having a meeting with it this friday.

Porsche944 · 06-04-2003, 02:41 PM

BTDT, burned the t-shirt.

Eturbo924 · 06-05-2003, 08:32 AM

Did you get a new manifold or header? I might have a nice unused one soon.

Eric

Taz's Master · 06-09-2003, 03:17 PM

I have another question. Did 944's come stock with tube manifolds, or are they cast? The manifold on my '86 is bent tubing, my replacement is from an '87 924s and is cast iron. The cast manifold (and this kills me to say it because I love headers) has to be a better flowing design. I am disapointed with the welds and the splicing. If this is an aftermarket design, it is crap, and I understand why highboost 951 said that headers are worth 1hp. If this is OEM, Porsche did a much better job with the cast manifolds.

By the way, the bolts on my tube manifolds were much easier than the ones on the cast manifolds (header to cat pipe), I can better understand your pain.

Kirby2 · 06-09-2003, 05:45 PM

I think early models came with cast, but most used 944 seem to have the tube upgrades.
I pulled mine from below(took a little wiggling) but not that bad.
I just had the muftler shop weld up the broken welds ($25). Remember to have him clamp the manifold to a base verry well to prevent warpage!!