Another question related to the manifold nut/studs. I have the original cast manifold on the Renault engine. There is one lower nut which is really difficult turn with the manifold being too close to the stud. In fact it looks so tight that the nut cannot turn. Is there meant to be some kind of shoulder nut here?
If it's one of the two bottom middle studs (Pic 1), I can see why you're having problems. As far as I can see, you can't fit a socket to fit over the nut, the closeness of the manifold runners prevents proper fit (Pic 2). If you look at the parts manual for the S2, I believe there should be a long spacer for those two studs. This is the service manual quote on removing the exhaust manifold.
"If the exhaust manifold gasket is to be replaced at the same time -
Remove the manifold.
Undo the four nuts and washers and the two socket bolts and washers, retaining the manifold to the cylinder head. Carefully remove the manifold and the gasket"
I don't see how anyone can tighten the exhaust nut without an extension spacer for those two bottom studs. FYI, on 65/2501, the manifold is secured by a long threaded spacer nut for an internal allen head tool on those two positions.
Sorry on not giving you a solution on the problem.
Joji Tokumoto
Fallbrook, CA