Cayenne 3.0 V6 TDI Ticking Noise - Injector seal replacement and seat cleaning

[Mirez]

So I've been on a quest recently to see what kind of MPG I can get from the big beast, 42Mpg was reasonably easy on a long run but wanting to get even better I thought I better fix the idle chuffing noise I have coming from the left bank.

The 3.0 V6 in the Cayenne is the VW Group engine that's also fitted to the Q7 and the Touareg along with a host of other models from Audi / VW such as the A6/A7/A8. It's a fairly solid lump with a couple of the weak spots, one of which is the injector seals. Having ordered a replacement set which consists of:

6x 059130519B - Injector Seat, Copper (BOSCH F00VP01009 as they are £12 each from VAG)
6x WHT004923B - Sealing Washer, Rubber
6x WHT000884 - Stretch Bolt



along with a tool set to clean the seat (read the notes below on that!)



I set about stripping the thing down, which is fairly easy. The usual fuel lines out the way, pop off the return lines and then unbolt the injector clamp before withdrawing the injector. Started with Cylinder 3 which went well, Cylinder 2 also good and then found the cause of my chuffing was Cylinder 1 which needed the slide hammer to pull it out it was so gunked. Interestingly VW have put a port into each of the orifices that the injectors sit in so when you get the blow-by it vents out to atmosphere instead of into the cam cover. The downside of that is that the crud comes out all over your engine, or specifically in the case of the Cayenne and Cylinder 1, the starter motor. It's been a little sluggish to start when hot and I now know why!

Cleaning out the seat is a little laborious since you can't use too much in the way of chemicals but this is where is got annoying and two BIG words of caution.

1 - The cleaning kit comes with metal sealing 'plugs' that you insert into the cylinder opening to stop crud going in. On mine, the plug was literally just big enough to fill the hole. Fortunately, before releasing it I tested with a little more force and it could be pushed into the cylinder without effort. For some reason Cylinder 2's opening was a fraction wider and it would have just past through into the block and a world of hurt. I used a spring washer in the end to increase the diameter and make sure that 100% couldn't happen but I think I'd take my chances on compressible carbon falling in then uncompressible metal if I didn't!

2 - Installing and withdrawing the plug means you are passing it through the cam area as the injectors aren't sealed off, make sure you have a good number of threads engaged before moving it through this area else it will fall off and get lodged in a really inconvenient location necessitating the need for cam cover removal, 2 hours extra faffing and a £50 dinner bill for your assistant...



Fun times, although on the plus side with the cam cover removed it is easier to clean our the seat...



Anyway once they are all cleaned, new washers and seals installed its just a case of reinstalling them and torquing up the new stretch bolt to a rather pathetic 6Nm and 90 degrees. I actually had to buy a new torque wrench for that as I didn't have one that went so low!

You don't need to take it off (unless you fall foul of number 2 above) but on a side note the swirl flap motor get's properly covered in EGR gunk so budget another 40 minutes to clean it all up if you go in that far!

 
 
With is all back together the chuffing tick at idle has gone and the idle is much smoother but the MPG has increased by some 4/5 with it getting 46Mpg on the same, cruise controlled, run - about as scientific as you can be in the real world.
Added bonus is that the lazy starter is also getting better now its not being covered in oily shite! Sadly its so squirreled away its impossible to get any cleaning chemicals on it but hopefully it will burn off on the next long motorway run.

[johnnyroper]

Can't beat a coked up injector, I have been fairly lucky that most I do come out without much hassle had a couple where slide hammer was needed. Only problem one I had was no6 on a bmw loads of soaking and slide hammering and it didn't budge,had to call TG Norris out 20 ton with his hydraulic gear finally shifted it.

You should have messaged I have a torque wrench that goes 5-25nm you could have used.

[SirDavidAlhambra]

It sounds like it was quite a complicated job but with a bit of careful planning it was done very nicely.

Look at all that carbon build-up, I bet it was nice scraping all that off.

I bet that Porsche goes really fast too!

[johnnyroper]

Do I also spot a timing chain at rear if engine like the bmw set up meaning engine out job?

[Mirez]

Most popped out without much effort, just cyl 1 that needed the hammer but I'm not sure I'd have wanted to go hydraulic on it lol!

Do I also spot a timing chain at rear if engine like the bmw set up meaning engine out job?

Sadly yes you do! For some weird and wonderful reason there are 4 of them as well but fortunately they are reasonably reliable, the right bank tensioner goes a little lazy but it's only on warm startup you hear it and they don't fail as such, just get weak when not pressurised from the oil.

Look at all that carbon build-up, I bet it was nice scraping all that off.

VERY

[johnnyroper]

Just looked at that set up with 4 chains,it's quite a complex looking design. Given they use it in other vag stuff it must be quite reliable as I haven't seen the horror stories like with the bmw ones. The secondary chain on them is like a bicycle chain sort of thickness,that's the one that 99% of the time fails. Certainly all the ones I have done has been that one anyway.

[KingyMAK]

The rear timing chains remind me of the RS4 B7.
Absolute nightmare of a job.

[Mirez]

You can largely hear the conversation in the design room, "Let's use a chain, they never fail" and nobody will ever need to access it for any reason what-so-ever!

That said its used in the Q5, Q7, Touareg, Cayenne, Panamera, A5, A6, A7 and a couple of Skoda's so any big failures would be well documented by now. It's one of the reasons I went for it over the petrol or V8 diesel as its well regarded and the only engine to use a 'down rated' transfer box, ironically though that box is massively reliable vs the uprated one that dies every 30K miles ish -eek!