Timing Chain Help
 

Hi, I currently have a 2004 996 carrera cabriolet. I was just wondering what steps i would have to go through to put the timing chain back on?
Sheng

is it off?
did you take it off?

It is currently off, and I didn't take it off. The person I know who took it off just wanted to make sure if they're doing it right at the moment. Also the cams are off too if that makes a difference.

Sheng

Go here:

http://www.cannell.co.uk/Manuals.htm

and scroll down to Porsche 996 and 996 Workshop Manual - Engine Part 2 and download PDF file.

It has directions for assembling cams and setting timing. You still need to know what you are doing though.

Sincerely,

Macster.

Thanks a bunch, this is exactly what I'm looking for.

Sheng

Just wondering if anyone can give me the answers quickly to this.

What is the torque sequence of the cylinder head bolts.
Also what is the timing for the timing chain bank 4-6.

Sheng

This has to be the most confusing post I have seen in a while!!! I have some questions for you.
*How far down do you, your buddy, whoever have the engine torn down? Are the cases split? What are you doing? Why are the cams out? I assume the engine is out of the car correct??? Do you have any special tools? :confused::confused::confused: WTF!!!

Engine is out for the correct car. There was an initial problem with the car losing power on fourth gear onward. Porsche said to replace the whole engine, so we ended up tearing down bank 4-6 to find there was something wrong with the valve. Now that bank 4-6 are opened up we have to put it all back together.

Sheng

OK. I am not at work to look at the Workshop Manual right now, but I can give some pointers until tomorrow AM. Cylinder head torque sequence is on page 19 in the PDF link provided above. :surr:BUTT:surr: that is all that manual is good for!!!!!!!!!!!!! That manual is for the 3.4L engine.:eek: The cam timing procedure is COMPLETELY DIFFERENT for your 2004 3.6L VARIO CAM PLUS engine.

Are you a independent workshop, our just some guys building this engine at your house? You are going to need special tools to set cam timing and torque the cam sprocket bolts!!!!!!! The intake cam can be a little tricky to intstall correctly!!!!

Ah... makes sense, I was talking to my buddy and he said the diagram isn't all the same as the engine we currently have out. The car itself is for an uncle of mine. Other than that thanks for the help you're providing.

Sheng

Do you guys have much engine building experience? Porsche experience? Do you have all the parts you need to complete the job? What did you find wrong with the valve (intake or exhaust)?

Personally I'm not sure, as I have limited knowledge, my buddy rebuilt a 944 engine pretty much from scratch before. As well as other engine. The 996 this is our first one, that's why I'm trying to accumulate as much information as possible. Yes we have all the parts we need to complete the job.

Sheng

Do you have a porsche dealer or qualified indy close to your location? Because I can tell you step by step how to install the cams and set camshaft timing, but you are going to need special tools to do this!!!!!! There is no way around this!!!!! Trust me, you do not want to F-this thing up. It can get very expensive very quick.

I have a Porsche dealer nearby, but don't really trust them since they wanted to put in a re-manufactured engine right away. Unless you mean just to get the special tools? Other than that if you can let me know how to do it step by step that will be a huge bonus.

Sheng

When you are just timing one bank, you must, I repeat MUST know for sure that the other bank (bank 1 in this case) is on TDC compression when you install the bank 2 cams in on overlap!! Cams are installed on OVERLAP (intake is just opening and exhaust is closing) For cyl#4 the camshaft lobes should point away from eachother when on overlap. (FYI, cams are installed on overlap because they are relaxed, no valves open, no pressure on cams for that bank), All you need to do is pull the cam plugs, (little green plugs, at the end of the cam cover) to see how the cams are allocated. When you pull out your green cam plugs, opposite end of camshaft sprockets. So for Bank 1 they will be on the front of the engine, below the alternator etc... for bank 2 they will be on the back of the engine (flywheel side). Once you have the plugs removed, you will see the ends of the camshafts. Rotate engine to TDC , the crank pully is marked "OT" and there will be a notch in the pully that lines up with a casting mark in the engine case the reads " OT Zyl 1". Fix the pully with pin, through hole marked "OT". You are now on either TDC compression #1 or overlap #1. This is why you must pull the green cam plugs. With the crank fixed @TDC, look at the ends of your camshafts for bank 1, If the smaller circular cutouts are pointing away from the engine then it can be said that cylinder #1 is on TDC overlap and cylinder #4 is on TDC compression. If the smaller circualr cutouts are pointing inward toward engine, then it can now be said that cyl #4 is on TDC overlap and cyl #1 is on TDC compression. Ok this is were it gets a little confusing. The camshafts must be installed with the crank 60 deg before TDC. If you look at the crankshaft pully, you will see the hole marked U6, you need to pin the crank threw this hole, so the crank is 60 deg before TDC "overlap" #4.

Prior to installing the camshafts, you should have installed all lifters with asseymbly lube or motor oil. The intake cam is very easy to screw up. The aluminum collar that covers the vario cam vane adjuster oil control rings, must be indexed to the cylinder head. You will see a pin in the center of bearing saddle, and then you must locate the blind hole in the aluminum collar on the intake camshaft. This blind hole (all the other holes are oil passages!!) must be fitted onto the pin. If you screw this up, you will have camshaft adjustment faults!!! Once the intake cam is installed on overlap, install the exhaust cam in on overlap (the lobes for cyl #4 should point away from eachother. Loosely fit the bearing caps, they cannot be mixed up, they must be re-installed from were they were removed!!! Fit the vario cam vane adjuster(sprocket), fit the exhaust cam gear (with the holes half coverd).DO NOT tighten Intake cam sprocket bolt at this time!!! Fit the chain guide rail between the sprockets, fit the chain tensioner. Remove pin from U6, Rotate the crank to TDC, hole OT and pin it.(this is how they remove slack from timing chain). The exhaust cam bolt holes should now come into view, install the special tool into to back of cams, tool #9686. Torque bearing sadles. Perform inital torque on the cams, 37 ftlbs on the intake and 10.5 on the exhasut. Remove cam timing tool from back of cams, (if you fail to do this, you run the risk of snapping the intake camshaft upon performing final torque.):icon501: Install special tool that looks like a old school telephone(9685), torque (new) intake cam bolt by additional 110 deg and you are done. Rotate crank 360 deg to check bank 1 with special tool 9686, rotate 360 re-check bank 2.

Like I said, I will look at the Workshop manual tomorrow and provide more info (special tool #s and torque specs) and maybe some pics. Good Luck........:corn::corn::corn: