The exhaust manifold on a 944 turbo consists of four pipes that are welded per pair. The 1 and 2 pipes are the outermost pipes. The 3 and 4 pipes are the middle pipes. Each pair of pipes connect to the crossover pipe. The exhaust manifold can develop cracks or broken welds over time and thus needs to be replaced some times. Removal of the exhaust manifold is also necessary to change the gaskets. This is a step by step procedure to replace the exhaust manifold.

Full procedure

1. Grab your best penetrating oil and blast all the exhaust manifold connections (crossover pipe bolts + head nuts and studs)
2. Remove the skid plates and put the car's front on jackstands.
3. If you have already replaced and rerouted your fuel lines that go above the manifold, great; you just made this job easier! If not, you'll have to uncouple the fuel lines (to do so, remove the DME relay from the fuse box, open the gas tank cap, crank the car a couple times to remove fuel pressure. Now unbolt the fuel line and drain it and put it to the side. Also loosen the other fuel line, and put it to the side after draining.)
4. Disconnect the battery for good measure.
5. Loosen the clamp that holds the powersteering reservoir to its bracket. Move the reservoir out of the way of the manifold.


Move the powersteering reservoir like so. Put some towels around it in case of a leak.

6. Take a turkey baster or a transfer pump, and pump out as much of the coolant reservoir as you can. You can re-use this coolant if you catch it in a suitable container!
7. Important: PUT THE COOLANT CAP BACK on the coolant tank; doing so will greatly reduce the coolant spilled in the next step.
8. Go to the exhaust manifold side of the engine, and you'll see a metal pipe running near the manifold connected to two rubber lines. This is a hard coolant line and you'll have to remove it. Start doing so by unbolting the two 6mm allen head bolts that hold it to the block.
9. With the hard line loose, proceed with undoing the clamp closest to the windshield. Be prepared, some coolant will spill out. So put a large catch tray under the car. Drain the small rubber line completely by holding it up and down a bit.
10. Do the same with the second clamp, closer to the front of the car. Again, some coolant will spill out, but if you've left the cap on the coolant tank, it will be very little. Do not be tempted to remove the cap after this part, you'll regret it (ask me how I know).
11. With the hard line now completely out of the way, move to under the car and undo the 6 bolts holding the crossover pipe to the exhaust manifold. In my case these are 13mm bolts and nuts, but yours may be an original 12 and 13mm. If you haven't removed these bolts for some time, be prepared with plenty of lubricant and cuss words.
12. Note: if you haven't done so already, you may want to upgrade the crossover to exhaust manifold connection with a Lindsey Racing copper gasket. This will help seal the connection.
13. With all 6 bolts removed, you are ready to move on to the exhaust manifold bolts. You should've given these plenty of lubrication already but do so once more.
14. Remove all M8 nuts and washers that are in place on the studs. To do so, you'll need a simple wrench and a tiny socket wrench. A wobble head with a short extension can help sometimes.
15. Once the exhaust manifold is loose, you are ready to remove the studs. Lubricate the studs again, this time you'll be able to put the lubricant closer to the head through the gaps that have been created with the removal of the manifold nuts.
16. You'll want to remove the 3 & 4 pipe first, the middle ones. These are the easiest to remove. Put a nut on the stud with the rounded off side to the head. Twist it on by hand or by wrench until you have just enough room for another nut. Put this second nut on with the rounded off side to you.


Take notice of the position of the nuts.

17. Take two 13mm wrenches and turn the outer nut to the right, and the inner nut to the left. Do this at the same time, and make it nice and tight.
18. Once they are nice and tight, you can put a 13mm wrench on the inner nut and turn it to the left. This will move the stud. Grab a flashlight and shine directly on the stud so you can ensure it is actually moving.
19. If the stud doesn't move, check if your double nuts are tight together. If they are, you may have a stuck stud. You can try to apply more penetrating oil and wait a bit, or use heat (preferably induction heat) to get the stud to break free.
20. Continue the process until all four studs for pipe 3 & 4 are removed. As you remove studs, the old gaskets will fall out. Prepare to catch them. Once the studs are out, lift out the 3 & 4 header.
21. With the 3 & 4 header removed, you'll notice that the crossover pipe is laid bare. Immediately block the pipe with tape, cloth or paper towels. You don't want anything to fall in there!
22. Continue the double nut process for the 1 & 2 header. You'll notice that the 2 header is the most difficult as the right most stud is partly obstructed by the heat shield. You'll need patience and a simple wrench to complete the job.
23. Once all studs are removed, you'll need to extract the 1 & 2 header from the engine bay. This seems more simple than it is. Try turning the number 2 pipe towards the number 1 pipe (rotate the header until it comes free).
24. With the headers removed, all that rests is a good cleaning and the reinstallation. Grab a scotch brite pad and put some elbow grease into those gasket locations.
25. A good while you are in there may be the replacement of the heat shield under the exhaust manifold. See my procedure here.
26. After cleaning, grab your 1 & 2 header, two gaskets and your new studs, washers and bolts. Put the gaskets with the metal side outwards, meaning that the metal side should touch the exhaust header pipes and not the head. Align the gasket and header, and put a stud with the short end into the block. Turn it in by hand until you can't any more. Depending on the type of stud, you'll need to double thread it (this time turn the outermost nut to the right to get the stud into the block) or use an allen key to insert the stud.
27. Torque the M8 nuts to 20 + 2 nm.
28. After the 1 & 2 header is in, put the 3 & 4 header in the same way. Obviously, torque these to the same 20 + 2 nm spec.
29. Don't forget to remove the paper/towel/tape from the crossover. Put in the (optional) Lindsey Racing copper gaskets. Bolt the 6 bolts back in to connect the crossover and exhaust manifold. Use 20 + 2Nm (14 +1.4 ftlb) of torque.
30. Replace the hard coolant line, tigthen the two bolts you removed to 20 Nm (14 ft-lbs).
31. Replace the powersteering reservoir.
32. Refill & vent the coolant system.
33. Replace the skid plates.
34. Put the DME relay back if you removed it.
35. Reconnect the battery.
36. Congratulations! You've replaced the exhaust manifold!