Following a issue that I had (See http://www.alfaowner.com/Forum/alfa-...-pictures.html
Post #16 for the picture, I needed and decided to remove my manifold...mainly due to:
1. Problem with a welded flange - Can't replace the rotten downpipe
2. Blowing from the exhaust manifold.
This guide does not involve removing the engine (which I want to do but need the car MOT'd first) or tilting the engine (Like in some GTA posts)
This guide will go through both options of replacing the rear manifold gasket and removal of the manifold. Please be aware that I am not am mechanic and what I have done has worked for me on a 1999 GTV V6 CF2. Do not attempt this if you feel you cannot do it. DO THIS AT YOUR OWN RISK.
I would rate this as 3 out of 5 for difficulty. I did use a breaker bar a few times, especially due to the tight nuts holding the subframe.
REMOVAL FOR MANIFOLD GASKET REPLACEMENT.
1. Disconnect the battery
2. Safely jack up the car, chocks at the rear of the car, I like to use the front wishbones where it joins the subframe and place axle stands under the points under the car.
3. Under the car, remove the short downpipe from the cat (and if you can) from the manifold itself.
4. Using a socket set, from over the plenum, undo the manifold nuts. you may lower the manifold to replace the old gasket for new ones. Be careful of the sensor and cable, it will be fragile. You can see the state of the manifold ports via a mirror. clean and replace the gasket...then everything in reverse to put back....around 25NM (check the manual)
IF YOU WANT TO REMOVE THE MANIFOLD FULLY....
5. Temporarily put the manifold back and fasten a nut to the stud to hold the manifold in place.
6. Disconnect the sensor from the long pipe and remove the long pipe from the manifold and from the cat.
7. Support the gearbox and remove the rear support bracket completely.
8. Drop the subframe by removing the necessary bolts. I tried to remove the manifold without dropping the subframe but undoing the steering rack...not enough room, the subframe has to be lowered.
9. Remove the holding nut from the manifold and from underneath, carefully maneuver the manifold out...be mindful of the delicate sensor.
10. To put back, the reverse. If you have to remove the tie rod end (I didn't) you will need to mark off where the track rod end sits before removal....or get your wheels realigned.
And that is it..it worked for me. One problem I do have is that I cant seem to completely remove the front subframe, seems to be getting caught on the front axles - I wanted to give it a quick clean and a paint...