Variocam Chain Wear Pad Replacement on 5 Chain Engine WITHOUT engine removal tips
I just finished replacing my Variocam chain pads on my 2000 Boxster 2.7 WITHOUT taking the engine out of the car and would like to share what I learned. Most of the write-ups, forum posts, and videos assume the engine is out of the car. I wanted to try it with the engine in the car for many reasons: I don't have a lift, I don't have an appropriate lift table to lower the engine, and I have no place to work on the engine once it is out and the car is disabled. Also I thought it may be faster to not bother with removing the engine and liked the challenge implied by forum posts about how difficult it was. I am a moderately skilled hobby mechanic and this was the biggest job I had ever considered - and happy to report it is done and went well with lots of little challenges along the way.
My intent with this DIY is to add little tips to get past these challenges. I am not going to reiterate the basic procedures that are very well documented online and in print. I can refer you to the Pelican DIY which is on their website and depicted in the "101 Projects" book, both excellent. My favorite video is "Don't neglect wear pads! How to fix camshaft deviation | Porsche 996/986 w/5-CHAIN ENGINES ONLY!" with Jake Raby, published by Porsche Club of America on YouTube. It depicts a 996 engine but the steps of the heart of the job are the same. Also "Porsche CAM TIMING CHAIN GUIDE RAIL Replacement/Install" by 'Help me DIY" on YouTube. He does the unthinkable, does the job with the engine in the car and films the entire thing, unedited, maybe 12 hours of footage complete with the struggles we all know but few people show in their videos. I also had the Porsche repair manual, downloaded and printed.
First off parts:
996-105-253-00 Porsche Guide Rail Set For Camshaft Adjuster x 2 (cam pads, the thing we are going after!)
999-701-647-40 green O-rings for chain pads x 2
996-105-170-54 Timing Chain - Cam to Cam / Single Row X 2
900-123-147-30 Tensioner crush washer silver x 2
996-104-215-54 Camshaft Head Plug (Green camshaft End Plug) X 6
999-707-554-40 O-Ring for Engine Oil scavenger Pumps 95 X 2.5 mm (Secondary Pumps) X 2
996-105-223-52 Camshaft actuator solenoid flange with oil seal Cover Piece/Flange on Valve Cover (2 Per Car) X 2
PAF-008-124 cam sprockets bolts 14 Nm
996-111-107-55 exhaust manifold gasket x 2
996-113-113-00 triangle exhaust manifold to second cat pipe gasket x 2
999-084-052-02 M8x1.25 nuts x 4 nut triangle exhaust joint
900-074-287-02 M8x1.25 bolt x 2 triangle exhaust joint
From eBay/Amazon/etc:
M6-1.0 x 45mm Flat Head Hex Socket Cap Screws for cam holding bar across cams when cam cover is off, these have big head, also called furniture bolts, very handy also to create 'shelf' by screwing in to head when replacing cams onto the head, they hold the cams roughly in place while you fiddle with getting the actuator in place. They are not included in the tool kit.
M8-1.25 x 30mm bolts to hold jig at the end of the cams, also the bolts that go into the ends of the cams were too short, these worked great. They are not included in the tool kit.
M5 Fully Threaded Rod, 250mm Length, 0.8mm Thread Pitch, Left Hand Threads, I cut this rod in half, only needed about 125mm, used to compress the variocam piston, very handy. Older cars had a different way to compress the actuator
M5 x0.8 left hand thread nuts for the rod
32mm Socket for Ecotec,TDI,VW,Audi,BMW,Polaris,GM,Volkswagen,Ponti ac Chevrolet,Saturn,Pontiac,Saab,Chevy, Oil Filter Socket for Oil Change, this worked perfectly for the tensioner removal/replacement
CAMSHAFT ALIGNMENT Engine Timing Tool Kit For Porsche 911/Boxster 996/997/987CAMSHAFT ALIGNMENT Engine Timing Tool Kit For Porsche 911/Boxster 996/997/987 - this seems to be the same tool kit available in a many places, shown with a molded blue case, the only parts I was able to use were the crossbars to hold the cams in, and the jig that holds the ends of the cams in - I had to use the M8-1.25 30mm bolts(above) as they did not include the center bolt and the two bolts for the end were too short
RV Scissor Jack Kit, 5,000 lbs. 24" Extended. This is used to hold the front of the engine as it is released from the motor mounts. These jacks are used to level camper trailers and have a metal platform at the top,I screwed a 2x4 block about 10" long to the platform.
Engine oil, filter
Loctite 1158514 Head Bolt and Water Jacket Sealant under the heads of the cam cover bolts to prevent leakage out the bolt holes
Loctite 4741 primer/activator for cam cover flanges, helps Loctite 518 cure
Loctite 518 Red Gasket Eliminator flange sealant
Disposable Glue Brushes 1/4" to spread flange sealant
Get started:
jack up, jack stands at 20 inches on jack/lift pads x 4, this was a good height for my longish arms, very comfortable. Leave room on the rear two jack stands to access 15mm bolt for the diagonal brace which must be removed
Drop engine:
I started the job without dropping the engine and it was maddeningly difficult to get to the green cam caps and bolts on the top of bank 1 cam cover, mirror to see them, super tight to get a ratchet and socket on them so I ended up dropping the engine 2-1/2" in the front, 3/4" at the rear and it all opened up to the point I could visualize and reach all of the bolts and get them off without too much trouble. It also made replacing the cam cover without mucking up the sealant on the flange much easier.
The challenge is dropping the engine is not breaking any of the 20 or so lines/wires/hoses that course from the engine to the body. Here's what I did:
Loosen clips and brackets that hold the PS lines and vacuum lines that travel along the bulkhead, driver side front bottom of engine compartment. These are right near the oil pump for Bank 2. This was easy to do and lets the lines come down with the engine nicely.
Remove air intake snorkel from TB and air box, 8mm, may not be needed, not sure, I did it.
Remove headers, this disconnects the engine from the muffler and allows the engine to move freely, also the headers and cat block the cam covers and make the job much easier:
Remove center plastic under-body trays/covers for water pump area and the long cover in front of that to expose coolant pipes
Loosen brackets x 2 that hold coolant hoses and pipes so they can lower with the engine
Place RV Scissor Jack at the front of the engine, I like the bosses where the cases are joined along with the front lip of the oil pan
15mm remove 4 nuts that hold the front motor mount to the car, leave the mount attached to the engine
15mm remove diagonal braces and stiffener plate
Floor jack under transmission
15mm remove bolts holding transmission mount wings to transmission, no need to completely remove these mounts
Place 1/4" thick by 10" board on frame crossmember to cushion transmission, lower transmission until it rests on the frame crossmember
Go back to the scissor jack and slowly lower the front of the engine, watch the hoses and lines and listen for things breaking.
I ended up with 2-1/2" drop at the front, maximum in rear was 3/4" as the transmission hits the frame crossmember
Once the engine is down a bit:
Remove top of PS reservoir to allow access to A/C bolt. Getting this little guy out is way easier with the engine lowered.
Loosen A/C compressor, one bolt between intake manifold runners, two bolts up front angled toward driver side, to allow access to the bank 2 tensioner. I ended up lifting the compressor up about 2 inches and putting wooden blocks in to keep it there so I could get at the bank 2 tensioner.
Remove plastic green cam cover caps x 6. This was very difficult and frustrating. Given the proximity of the car frame I couldn't get a good angle on the caps with any tool. Also it turns out these caps are only 'puncture-able' in the very center, on the back of them is a metal reinforcing washer with an open center. I accidentally pushed one into the engine, luckily I was on my way in there so it later fell out. My best tool was a screwdriver that had a partially broken tip so it had a sharp diagonal tip and I could puncture and pry the caps out. Still not easy, about a 10 inch thin but strong awl would be best.
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