Cleaning TDI intake manifold
This how-to will cover cleaning the engine intake on diesel engines with EGR, specifically Volkswagen TDI engines.
Oil from the PCV/CCV or leaky turbo seals mixes with the soot in the exhaust gas from the EGR and makes a sticky mess in the EGR valve and intake effectively clogging it.
Many ways to do this including chemical/hot tank or walnut blasting but not everyone has these at home. Another way to do this at home is burn the oil out and then either use a heated pressure washer or fill with oven cleaner then pressure wash out.
Youtube video of the process at the bottom.
2X6 wood or something to snuff the fire
Fire extinguisher or water hose (incase things get out of hand)
Gloves (oven cleaner causes chemical burns)
Remember throughout this entire process the intakes made of aluminum so don't let it get to hot as it'll turn into a puddle. Using a mini-torch start heating the soot/oil.
The flame will starve for air so this is where the compressed air comes into play. Keep adding air until the intake is too hot or the soot is no longer sticky.
The oil will burn hot and once going it can be tricky to put out, snuff the fire with scrap wood. Avoid water as the sudden temperature change can cause the manifold to crack.
Once cool scrape the soot out as best as possible
I didn't get any pictures of this process as things get messy quick.
A quality heated pressure washer should clean the remainder out. If you don't have one or it didn't clean well enough fill it up with oven cleaner, let sit and then pressure wash out. Oven cleaner can cause burns as well as make a mess when mixed with soot so make sure you have a suitable area.