This was a scary one but in the end, turned out okay, but possibly could have been worse.
The short story was that for a couple of weeks now if I drive her hard and do 140kph+, after a short while the dipstick pops out and oil and smoke started coming out of the dipstick.
Initially, I put it down to a faulty dipstick, however a couple of days ago it was pretty bad, I just had the manifold changed, I drove about 5km on the motorway giving it some, and suddenly lost power so had to pull off to the side of the road.
When I opened the bonnet, there was the dipstick out of its slot and oil spraying all over the inside of the engine.
I carefully drove back to my garage, carefully applied degreaser on all the oiled areas, followed by a careful jetwash and cleaned it up and spent the evening trying to troubleshoot the issue.
Root Cause was Faulty PCV Valve on the Touareg R5
After spending some time around on the VW forums and Youtube, everything was pointing towards the PCV valve which sits right on top of the engine.
Basically, the PCV valve regulates the airflow from the compression chamber in the diesel engine so if there is a certain level of pressure in the engine, it’s released through the PCV valve and sent down a pipe to the air filter, then it gets sent to the ECG and out the exhaust system.
€30 Fix in the end!
To change the PCV valve is really simple, you can literally just pull the old one out and pop the new one in and best of all it only costs €30 for an OEM part.