I think I have a small exhaust leak right at the passenger side manifold where it meets the block.

What all do you have to do to change that gasket? Can you leave the manifold attached to the Y-pipe and get it back far enough to slip a new gasket in? What about the EGR and air pipes? Do you have to do it when the bolts are warm?

thanks.

 

In a word yes.
Leave them attached. Undo the 6? bolts. CARFULLY, with LOTS of penetrating fluid, and a soft ratchet.
The manifold has enough give to pop out about an inch or so.
When putting the new ones in, there is a "hook" an open bolt hole. USE IT. You can put a bolt in NOT ALL THE WAY, and let one end of the gasket rest on it. Using the other hand, hold the bottom of the manifold letting the gasket fall into place and rest on your fingers. Start another bolt with your free hand.

Or do it in reverse, where you put a bolt through the hole, then raise the gasket over the manifold put in a bolt and then let it fall onto the bolt.

 

What exhaust manifold gasket? Mt 2.8 never had any. Never leaked either.

 

They never came with exhaust gaskets. The 2.8/3.1 are also NOTORIOUS for snapping exhaust manifold bolts. My RS has 2 broken exhaust bolts that broke inside the head.

BUT, you can buy exhaust manifold gaskets for the 2.8/3.1 even though they never came with them from the factory.

 

Rear most two bolts? Mine too (3.1). I've worked on getting the broken portions out with no luck, no room back there. I figure someday I'll unbolt the engine/trans, remove hood, lift and rotate the combo for access.

As for gaskets, didn't come with them but are available for many engines that didn't have them originally. After a while the stock manifolds warp a little which causes leaks. This is even more critical with the closed loop EFI systems as any leakage affects the O2 sensor reading.

RBob.

 

There is a reason no gaskets were used. Cause they out lawed asbestos. Even in our high tech world there isn't much or many products that can handle the heat and not blow out. Even the best gaskets will seal but the center will blow out eventually. Its just a matter of time.


I think, I think [not sure on who owns it] But I think headmen has a paten design for gasket less headers. They look to have a raised surface or bead of softer metal that is the "gasket".

 

eek, now i am kinda nervous about trying. It would probably seal even worse if that happened I suppose.

What about the EGR and air pipes, you can just leave those as you pull back the manifold?

So is it really worth it? What is the major effect of a leak there ?

 

When i replaced the head gasket on my 2.8 i first tried to remove the exhaust manifold without any pb blaster. I broke the first bolt i tried to get out. So i sprayed every bolt down with pb blaster. Let it sit for a few hours then went back and tried again. All of them came out without a problem. Also i heard of someone heatin the bolts up with map gas before trying to remove them, i would'nt use pb and the map gas though. Also about the egr. I'd remove the egr tube from the plenum, less chance of it breaking there then down near the exaust. But thats just me.

 

What is pb blaster (lubricant of somekind I presume) and where can you get it?

 

any auto or service store.
Yellow can, black top. about 4-5 bucks usually.

 

I've never had PB Blaster work better than Liquid Wrench... whichever of the two is closest is what I usually grab. The key is "time", you can't spray a penetrant on a rusted fastener and expect it to work in a minute. Heck, when I initially loosened my y-pipe-to-manifold-nuts, I was spraying those nuts down for over a week before I tried to loosen 'em- and they came right out. When you re-assemble the parts, coat the threads with some anti-sieze to make life "easier" in the future.

All the snapped exhaust manifold bolt I've ever touched have come out Easy, with a pair of visegrips super-tightened on the remaining stud, and one LIGHT tap with a hammer. When the exhaust manifold get heated up, they warp (like Rbob said), and after a bunch of miles, the manifolds seem to like popping the heads off of the bolts.

Note that I said "remaining stud"! I've been lucky enough not to have one that snapped flush with the head, which would require some drilling and an EZ-out.

So it's possible you could take the exhaust manifold off, and if there's a remnant of the bolt that you can put vise grips on, you're set. The bolt doesn't necessarily rust to the head, so it should be easy to remove. I posted the bolt spec sizes a while ago on here, so if you do a <a href="search.php?s="><img src="images/top_search.gif" alt="Search" border="0"></a> in the "V6 forum" for posts by "TomP" for something like, oh, I dunno, "exhaust manifold bolt", you should find 'em.

I wouldn't use a gasket though, between the head and the exhaust manifold. With the manifold off, lay a straightedge across the manifold's ports and if they all line up, you should just install new bolts and torque TO SPEC, not too tight, and definately not too loose.

I think your biggest worry for snapping something would be if you separate the exhaust manifold from the y-pipe. Those nuts will be hell. When I bored out the donuts between the manifold and y-pipe, I snapped a stud on the driver's side- but I happened to have a spare manifold in the basement! But I still have to replace the stud to make that broken manifold back into a "spare" manifold. And, luckily, camaro_junkie hooked us up with the part # for the y-pipe-to-manifold studs! Find it here: https://www.thirdgen.org/techbb2/sho...20#post1817442