3.0 TDI Valley Coolant Leak [VAG 3L V6 Diesel Gen2] 2013 Porsche Cayenne 958, Audi Q7, VW Touareg

3.0 TDI Valley Coolant Leak [VAG 3L V6 Diesel Gen2] 2013 Porsche Cayenne 958, Audi Q7, VW Touareg
I investigated an antifreeze leak on my 3L TDI V6 Porsche Cayenne Diesel and discovered the very common V6 engine valley coolant leak.
Here are the tools I used in this video:
Torx Sockets (you'll use the T30 a lot): ebay.us/xmnJdi
Long Torx Bits: ebay.us/TJ9C3I
Torx Screwdrivers: ebay.us/3gTd4B
Spline Drive Sockets (triple square): ebay.us/jGRBND
Allen Keys (you'll need the 5mm): ebay.us/896VDZ
Wet/Dry Shop Vac: ebay.us/k8YHyV
Mechanics Mirror: ebay.us/XQRbqI
27mm Deep Socket (for the fuel pressure sensor): ebay.us/i5YJ4F
And here are the parts you need to do this job:
EGR Cooler Intermediate Flange: ebay.us/pcd4SN
Oil Cooler Gasket Upper: ebay.us/q08wxp
Oil Cooler Gasket Lower: ebay.us/B94hkI
Intake Manifold Gasket Set: ebay.us/E5elGN
Intake Throttle Pipe Gasket: ebay.us/2hQafQ
Throttle Body Seal: ebay.us/EVzpki
Intake Manifold Gasket: ebay.us/tU2LAO
These Porsche Cayenne diesels feature VAG group engines, this was one of my main reasons for selecting a Cayenne V6 TDI, knowing parts would be easily cross-referenced from VW or Audi as opposed to paying Porsche dealer prices. After all this Porsche is pretty much an Audi Q7 or a VW Touareg in a business suit.
Also, with these diesel motors being used in so many different cars, I figured there would also be plenty of aftermarket support and a wealth of knowledge published online.
These V6 diesel engines are known to be very reliable and rack up huge miles without issue. But unfortunately they are not completely without problems, the coolant system is one of the weak points thanks to the use of cheap plastic parts and positioning them in the valley of the engine where there are extreme heat cycles. These parts become brittle over time and they leak.
When I first noticed my Cayenne was losing coolant without any evidence of a leak on the drive, I feared the worst and that it might be a blown head gasket. However, I then read up about how common these engine valley coolant leaks were and opted to investigate that further.
As my car is a 2013, it's over 10 years old, and has 130k miles on the clock, I should have expected this type of issue any moment, it's not a case of if they will leak, only when. At this age and mileage, it's been on borrowed time for a while, and my long road trip to Germany with the family must've been the turning point.
With the way these modern diesel engines are packaged, it's a very daunting task to work on them versus older cars. They are overly complex thanks to their emissions systems, and these are sadly their Achilles heel.
Start by removing the engine cover and vanity covers. Then remove the intake tube between the two throttle bodies, into which the EGR flows. You will use T30 Torx almost exclusively, with the occasional 5mm Allen head.
At this point I noticed how unbelievably dirty my intake was with oil and soot, clearly it has not been cleaned in 130k miles so I added that to the list, when cleaned it will likely increase performance.
With that removed, start to remove the wiring which is secured to the top of the intake manifold. With that out of the way, remove high-pressure fuel line that bridges between the two heads, at the rear of the manifold.
With that out of the way, remove the 12 torx screws holding the intake manifold to the head. And remove the fuel pressure regulator from the fuel rail with a deep 27mm socket (I didn't have one so I took the fuel rail bolts out and levered it).
Once this is done wrestle the manifold out of its home. With that done, you will be able to get a clear view into the engine valley to see the coolant swimming pool.
I then sucked out all of the coolant with a wet vac and proceeded to remove the EGR cooler, the EGR coolant valve, the oil cooler, and the oil cooler base plate. which caused another swimming pool, this time with oil.
Having done that, I identified the plastic intermediate flange which feeds between the engine block and the EGR cooler as broken, this is very common and hopefully the source of my problems as its a very cheap part.
If you are unlucky, it can be the plastic cover/pipe which is screwed the the rear of the front plate of the engine. If you need to change this, you have to remove the front plate and they pulleys etc which doubles the job at least.
For more helpful how-to guides and restoration project logs, visit our blog: www.spannerras...
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#porschecayenne #cayenne958 #3.0tdi #vag #coolant #coolantleak

[@Solder-Flowz]

What a great channel. I've just subscribed after watching your struggle with starting up the E30. I have replaced the engine on my E38 (M52B28TU) and I'll be starting it soon, hopefully with smoother results 😅 And then I look at your newest video and you're fixing coolant leak on VAG 3.0tdi, which I had in my daily driver A5 a year ago. I fixed mine with Liqui Moly stop leak 😂

[@morseoneuk]

Brilliant! I was nervously sweating just watching you..

[@SPANNERRASH]

Haha cheers! It felt like a heck of a job taking the thing apart. Whoever designed it was not planning to ever work on it... I've not had to actually take my shoes off and get into an engine bay before. 🤣 Doesn't help that the Cayenne is massive either.

[@philw4053]

I don't have the car but still found the video really interesting. If it had been me doing it one of the bolts would have snapped off in the block😊. Well done (hopefully)! Looking forward to seeing if that fixed it.

[@SPANNERRASH]

Thanks Phil, I hope it was entertaining for you. This Cayenne is not as fun to work on as an old BMW or a bike. Thankfully no snapped bolts this time though.

[@davidbailey6262]

Brilliant video! I have the same car.

[@SPANNERRASH]

Awesome, really hope it comes in useful for you David. Lovely cars to drive these, but maybe not that lovely to work on. 😆

[@geoffreysummers1229]

I recently has a German specialist mechanic centre do that Job for me. I'm in Australia (Gold Coast). They Quoted me only 8 hours labour so I jumped at it. They changed the reg valve in there and every seal they said may fail. Still their hourly rate was a little high at about 100 pounds an hour ($200AUD). I am happy. Job also include oil and coolant change. They quoted Parts at Porsche prices.

[@SPANNERRASH]

Sounds like you got a pretty solid deal there to be fair. On the FB groups people talk about getting quoted 5k or even more to do this type of job. Maybe because they aren't sure what they will find within.

[@geoffreysummers1229]

@@SPANNERRASH Total cost was AUD$2600.00 including parts and oil change using Mobile 1 oil . That’s what they said they used. The place was called German Dynamics.

[@4RingsRetro]

Great job buddy, that was well worth investigating the other potential issue areas whilst you were in there. Thorough wrenching that. Is the engine vibration what's causing the flange to snap? Is there an upgrade available? What a car though! Looking forward to more content on it.

[@SPANNERRASH]

Thanks pal, glad you enjoyed the vid. This VAG 3L TDI is far too intricately put together for its own good, no wonder they get valley leaks with the number of plastic parts and rubber seals... It might well be the vibrations causing the intermediate flange to snap actually. Mine definitely looks like it's been broken and leaking for a while. Really hoping that's the whole problem, it seems likely right now. I've seen billet replacements for them, but they seem to be only compatible with EGR deletes, and I've decided not to go down that route as I don't think it's allowed. 😅 I am planning to replace with another plastic one and hope it goes for another 130k miles!

[@4RingsRetro]

@@SPANNERRASH There's a good chance there's been an amendment to the design, maybe a wider neck? Yes, EGR deletes are not allowed, which is a shame as the whole EGR system has added a whole bunch of issues to diesel engines. You can get them mapped out, and then you can blank them off. Good luck, hope the new part sorts it. It seems very likely it's the only source of the leak. Love the channel dude, absolutely no pretentiousness. 👍🏻