Rennlist - Porsche Discussion Forums - 955 Cayenne DIY: Valve Cover Replacement

So I tackled the valve cover gasket replacement this week. It's a major PITA -- on par with doing the dreaded coolant tubes and tees.

I did the gasket replacement because my valve covers were oily/dirty and I was having a burning oil smell and wisps of smoke were seen coming from the exhaust area on the left side of the engine (when viewed from the front).

The Pelican instructions linked above are very good, but I'll add a few extra thoughts here that may help others:

1) Don't even think about starting this job without the following tools:
- Very low profile bit ratchet like this one: https://www.eastwood.com/eastwood-29-piece-ratchet-and-bit-set.html
- You may also want a set of l-shaped torx wrenches (like allen wrenches, but torx ended)
- 12 point spline bit set (for torque arm)
- Torx socket set
- Reverse torx socket set
- Full complement of metric sockets, socket extensions, wobbles, and u-joints to go with your sockets.
- oil resistant gasket maker/sealer (small tube)
- Some self fusing tape (you run a high risk of cracking a vacuum line for the brakes or one of the breather lines)
- You may also want some large sockets in various sized for the cam adjuster seals (more below)

2) When the Pelican instructions say 5 hours, I think that's how much you should budget per side (at least the first time you do this). Plan on taking 2 days. I started with the torque arm side which is slightly harder, but the driver's side (LHD) has it's own challenges. Once you know the drill (and which assortment of tools you need to reach the various bolts), I'm sure it could be done quicker, but it's a lot of awkward fasteners to undo and redo. Note that Pelican rates this job a 5 out of 5 stars for difficulty — it’s tedious work with lots of opportunities to drop a fastener into The Abyss....

3) There are several common repair/replacements that likely should be considered at the same time as the valve cover gaskets:
- Coils and plugs (this is well discussed — search is your friend)
- Camshaft adjuster seals (under the black caps on the top/front of each valve cover). You need 2 of these: https://www.pelicanparts.com/More_Info/94810593400.htm?pn=948-105-934-00
- Torque arm https://www.pelicanparts.com/More_In...375-101-13-INT
- The infamous vacuum/brake booster/pump line with all the check valves, tees, and bends -- if it's not cracked, it will, so might as replace it. https://www.pelicanparts.com/More_In...355-579-51-OEM
- Air filters -- if they're ready for replacement, you may consider it as you'll be removing them anyway

I’ll be going back in to do my torque arm and vacuum brake hose soon.....

4) On the passenger side cover (LHD), the real "beach" is the lower bolt closest to the firewall (and the middle one just above it is also a challenge). Access to both is really tight. This is where you need a low profile bit ratchet — the total height isn’t much more than an inch. The bolts aren't crazy tight (hopefully), which is good, as most wrenches that fit are less than 6" long and you wont get a ton of leverage. Once those rear bolts are cracked, you can usually spin them the rest of the way with your fingers.

5) Once you get the bolts done (and double checked that you did remove them all), you may find that the valve cover is still stuck tight. I put a 1/4 drive extension in each of the bolt holes and gave it a gentle bump in several directions to break the seal to the head. Be gentle -- the valve covers are plastic -- you cant lever them as if they were metal. Eventually the method I described will free them. Then be VERY CAREFUL lifting the valve cover straight up first before sliding it out of the engine bay to avoid bending/breaking the cam shaft fingers that Don references in his warning above.

6) The driver's side valve cover (LHD) has the dreaded wire that goes to the AC compressor. The Pelican instructions are pretty quiet on this, but it's a bear -- and in my opinion there's not much additional room you get from loosening the wire loom along the injector rail. I managed to free up enough slack in the wire to allow the valve cover to slide out by going under the car and unplugging the connector on the AC compressor and fishing the lower part of the connector upwards by pulling gently from the top. This required me to remove all the splash panels, remove the pressure hose between the driver’s side turbo and inter cooler and also remove the wheel liner on the left front for best access. It truly sucked and added a lot of time to the job which is why you’ll find some reports on the forums suggesting that you cut the wire and resolder it. While I’m usually opposed to such hacks, it’s not as awful as it sounds in this case, especially since there’s some chance you’ll damage the wire by pulling it from the top (it’s routed through numerous clips that you can’t easily access so you’ll be really screwed if you do). So yeah, if I did it again, I’d probably cut the wire around where it passes the coil pack — a clean splice could would be hidden and well protected under the beauty covers. That would probably save an hour or two.

7) If you're doing the camshaft adjuster seals (and you should as they are cheap and otherwise inaccessible), you'll need a collection of BIG sockets or similar objects to drive the old seal out from the inside of the valve cover. Be gentle -- it's all plastic. I used a mallet to gently tap them out on a piece of wood. I first used a pick to remove the rubber grommet from the inside — you’ll quickly find there’s a metal ring under the rubber that protrudes through the center — it’s this ring that you need to push through. I used another big socket to lightly drive the new seal back in from the top side. The fresh seal is much easier to move, but remember to be careful.

That's all I can think of for now. I spent the better part of 2 days doing the repair with all the ancillary fixes required along the way.

Good luck.