Exhaust Manifold removal (USA) 1978 S2

[fxTrader]

Any tricks to make it easy to remove and replace the exhuast manifold on my S2?

I have a spare manifold in perfect shape.

The one on the vehicle now has several hairline cracks and is leaking bad and it also sounds like crap.

Do I really have to remove the engine to swap the manifolds ?

I was hoping and planning on enjoying the car for one year (summer 2007) before any major work.

Thanks.

[USAndretti42]

I've taken the exhaust fanimold off my S2 several times without too much trouble but it's not a quick process.

I always start by removing the air-injection rail. This involves undoing the nylon pipe clip by using pliers to slide one half of the clip sideways off the other half and then puling the pipe off the one-way valve. Chances are the nylon clip will break as it has become brittle because of the heat. Well I broke mine anyway.

I loosen slightly the cam cover bolts that hold the air-injection rail and undo the screws that go through these and into the ends of the rail. A 13 mm open-ended spanner will do the job of releasing the rail connections to the head, two per port. To aid access to these, I jack up the car and remove the driver's side rear wheel. You can then get to all the air-injection connections and manifold nuts from below.

After the air-injection is out of the way, undo the downpipe from the silencer and from the manifold to give some more fighting room. I think it's 8 or 6 mm spanner that you need to undo the little nuts and bolts to release the heat shield over the engine mount. You should be able to wiggle it out of the way. If not, you will have to loosen the engine mount by removing the three bolts holding it to the block, 13 mm spanner again, and jack up the engine to get more space for manouvering the heat shield out. You need to do this at some stage anyway to get the manifold out. Undo the screws holding the mount to the chassis and remove it.

Undoing the manifold nuts us a tedious business as you can turn them about half a flat at a time. I didn't have a problem with seized nuts although a couple brought the studs out with them. Some other studs were missing completely which made life easier, Others, particularly turbo owners I think, have to use Dremels with cutting blades to cut through the nuts to get them off. Once all the nuts are off you pull the manifold off the studs and find it hits the chassis. Now you jack up the engine until the manifold clears and you can slide it off the studs. Now, I couldn't get the manifold out of the engine bay so I undid the chassis diagonal tube by removing the bolt at the front and loosening the one at its rear and pulled the manifold out of the ensuing gap.

I got replacements for the missing studs from JAE and Jeff advised using the turbo's parts as they are better quality. These were slightly longer than the old ones and the nuts that came with them were 12 mm across flats.

Re-assembly is a reverse of the above. Note that the gaskets will try to fall off the studs because of the angle of the head face so be careful to not damage them when you slide the manifold back onto its studs. I get all the nuts started on the studs before tightening any of them because a couple of them will not go onto the stud when the manifold is up against the head. The ends of the studs are too near bulges in the manifold to get the nuts through the gap. I do the same with the engine mount bolts fitting them all loosely. I also use a liberal amount of Copaslip on the manifold nuts and the air-injection connections. You can get Copaslip from JAE.

To answer your original question, you do not have to remove the engine to remove the exhaust manifold.