my buddy and I just finished the timing chain replacement for my 200k km 04 CTT. the instruction is online and you can find it by searching "cayenne cylinder cover" it is a pdf file and everything is nice and clear.

the reason we did it was the P0016 code. durametric shows the deviation angle for bank 1 is at -15 CA and bank 2 is around -5 CA (crankshaft angle, actual camshaft angle is half of that). acceptable range is -6 to +6. after extensive research, we decided to give it a try. either the chain is stretched or somethine else messed up in there. there are more info reagrding the readings on the boxter forum. apparently they have that problem a lot before the bearing fails.

some thoughts here if anyone wants to try it

• i call it semi DIY since we did it at my buddy's shop. you gonna need a lift and a lot of mechanic tools. so do not try it at home.
• it took us about 30 hours, it is a big job
• parts cost a little over $2000. we changed starter, water pump, water pump pully, theromostat, chain, chain guides(5 total), tensioner, all the o-rings that we could reach, all the gaskets we could see, some broken pipe/line, the screws for the 4 camshafts, the washer for the 4 camshafts($16 each). locktie, silicon, steering oil, coolant, engine oil, transmission oil, A/C R134. each part is not much but there are LOTs of them
• we did it without lifting the engine. instead we removed the bumper and the rad support (rad and all that stuff came with it). it was not that bad.
• my chain did stretched, about 1/4" longer than the new one.
• one of my chain guide has a broken contact surface where the chain slides over. looks pretty scary
• you will need the special timing setting tool (camshaft guide P9678). basically its two pieces of metal and costs $130 but you will need it. do NOT need the locating pin P9595/1 and the socket P9714.
• when setting the timing, make sure rotate the crankshaft before locking it at the cylinder 1 ingnition TDC. this way the chain is tight. we did not do that when we set the timing for the frist time. and the camshaft was way off (i would say around 10 degree at cam) after we set it and rotate and re check. it sucks. a mirror comes in handy here.
• the camshaft guide tool P9678 fits into the slots at the end of the camshafts. very tight there. there was zero movement. one piece for each bank. adjust the timing for both bank at the same time while keeping the crankshaft locked.
• there are NO keys on the timing gear sprockets. I was shocked when I saw that. In another word, if the screw that connects the sprockets and the camshafts is getting loose, the timing will fly all over the place. they stay in place only by the friction. I could not understand why they designed it this way. thats why my deviation for bank 1 was -15 which basically means that the sprocket was not staying with the camshaft
• use thicker 5w40 instead of 0w40 for high mileage cayennes
• clean up as much as you can. it is really gressy and nasty in there.

after this i checked the deviation angles
bank1 +4 CA and bank2 -3 CA. (so thats +2 and -1.5 degree at the camshaft)and the car idles much smoother now. I am really happy with the results.

 

Wow, great write up! I'm hoping that I don't get the p0016 anytime soon! Thanks for the good info. Just curious, the damaged chain guide you had, did you have any idea that it was damaged? Any noises from the front of the engine? And what about keying the camshafts? I wonder if a machinist could key the camshafts and sprockets? Ofcorse it doesn't sound like a common issue, but still. I'm surprised that it would be built like that as well! you happen to take any pictures of the r&r?

 

thanks Scot. I was talking to you before regarding the PCV valve. It was actually damaged. I am glad I replaced that. thanks.
P0016 seems not as common for cayennes. I talked to the parts manager and the technitians of the dealer. He told me they did some chain replacement before. he thought it was not quite common simply because there were not as many CTTs out there hitting 200k km. and when they are at 200k km, people just do not bother to fix it no more especially a big job like this. I am glad I only have to pay the parts. my buddy charge me $150 for the labor LOL.
for the cracked chain guide, if you standing in front of the car and facing the engine, it is the one that is on your right hand side right "after" the crankshaft. this side has higher tension than the one on your left hand considering the directiong of the chain movement. the guide is a two layer construction. bottom is the supporting layer and the top layer is a smooth plastic layer which the chain slides over. I had no idea it was damaged until i saw it. there is a crack about 1/8" big and i checked the fitting between the top layer and the bottom layer, it seems they are still holding in place. so i assume that 1/8" was fallying off. I coud be wrong since the guide is really gressy. all other guides has slight sliding grove on the top layer, but nothing that would extended the chain. a good tensioner would compensate for taht for sure. but i changed all of them since "I was there" and the cracked one concerns me. guides are about $60 each.
there was tapping noise at the front part. after r&r it tuned down quite a bit.
the most significant change was the rough idle. it was pretty bad before even after i flushed it. after rr, it is much smoother. and the gas paddle feels lighter too.
I do not think it is possible to make a key there. only thing between the sprockets and the camshafts are the $16 diamond washer (according to the instruction, and part list call them spacers, they are really really thin, no more than a piece of printer paper, i wonder what kind of "space" they could provide,lol) and on the exhaust side it is the sprocket, and on the intake side it is the vario cam adjuster, there is no space to fit any sort of locking machanism there i think.
I did have some pictures but not as insturctive to become an instruction. like i said the pdf instruction online is nice and clear. there was no tricky part except when setting the timing we did it 3 times. only reason it took so long was the amout of work involved. it took us 3 hours to remove the bumper, and the rad support. labot guide quotes 17 hours for rr the chain only. some part is very tight.
I am glad we did it and the car feels smoother and more powerful now.
only thing is that there is a small oval head screw that we could not put it back. have no idea where it belongs. LOL time will tell i guess

Roy

 

Roy, good info and good to hear your beast is doing better! Mine is getting up there in mileage too so I better start to think of a plan if something like that should happen. Well it sounds like you guys did a good job. Throw some pics up if you get bored.

 

Scot, you can check the readings with Durametric very easy.
camshaft deviation should be in the range of -6 CA to +CA and the readings should be rock solid no change regardless of rpm or temp or whatever. if it jumps around then i assume the sprockets start to move w.r.t the camshafts. i have no idea why the engineers did not design a locking key some sort there.
when idle, actual camshaft angle should be at 0,
at 2000 rpm, actual camshaft angle goes higher reflecting the advancing of timing. around 30 CA more or less.
both banks should have close readings. this way it is "balanced"

 

Ok, I'll have to pick up the Durametric tool soon!

 

You should Scot. Its worth it

 

So if the p0016 code is thrown, is that more than likely meaning the timing chain is needed to be replaced? Or maybe just the sensors? My 05 ctt is now throwing just this code. The engine light comes and goes.

 

It can be a sensor, cam adjuster, oil pressure issue (cam adjusters are hydraulic) or a stretched timing chain. I'd start by ruling out the simple stuff.

 

Any symptoms behind a stretched chain?

 

Aside from physically checking the chain... You might get some rattling. How many miles do you have?

 

There's no rattle. It's at 123,00 miles but I just bought the vehicle this year. No prior history is known.

 

I didn't think timing chains could stretch or get out of loop. Now timing belts tho, I can understand

 

Chains do stretch, and it's possible at 123k that yours has (you're right around the same mileage as the OP), but it is very uncommon to stretch enough to cause this fault. For sure I'd check the other stuff first.

 

I guess it does have a bit of a rattle. I have a video of the sound of the engine. But I do not know how to upload?