My 2007 Mk2 has the flat air filter and the air inlet is from below, which looks different from the photos here of the Mk2.5 - would I need to buy a new air box to allow me to fit a conical or cylindrical filter?
To answer your question mate,
Yes you would need to change your induction box and possibly the rubber induction feed to fit the new air box that takes the cyndrical style induction filter.
However you can purchase a panel filter from Green Cotton Induction to fit your existing air box,
There's no difference in performance between the panel filter and cylindrical type in fact my new project car runs 160bhp from the factory and its fitted with a panel filter induction box. What I'm trying to say is; the panel filter style induction box's don't harness loss in power compared to the cylindrical type so I personally wouldnt bother changing it.
Also, I have oil seeping at the hose joints between the air box and turbo, and a bit of staining on the filter itself, but not too bad. I've been told that this shouldn't really happen but a small bit of oil like this isn't a problem. What are your thoughts on this? Logically, I would have thought that the air flow from filter towards the turbo shouldn't let this happen, but it clearly is. It has been like this since the first time I openned the bonnet about 80,000 miles ago and I tend to clean it with a rag whenever I do an oil change. I guess I should change the air filter more often than normal to keep up performance and air flow. Should I be worried?
That hose that is between your air box and turbo is called "oil breather pipe"
It basically runs from the crank case to your induction pipe,
Its purpose is to dump excess oil out of the engine and in to your induction where it will be incinerated as part of the combustion.
Now that's how it works but its not ideal to be honest.
Diesel induction systems are designed to suck in clean DRY air only.
And when I say dry; I mean oil free aswell as moisture free,
I recommend you purchase an oil catch tank from ebay,
take the car off the road for 24 hours
Carefully remove the induction system including rubber hose feeding to the turbo,
Consult your local motor factors for some sort of cleanng agen that removes oil but doesnt damage rubber.
WD-40 perhaps but it turs your rubber a smoky white.
Clean the whole induction system then store it in the house until its bone dry,
Followed by refitting to your car.
Now ill explain what the oil catch tank does and how to fit,
Th oil catch tank has a two pipes on the top
It also comes with some hose,
The hose coming from the engine goes to the inlet port on the catch tank,
Then the outlet connects to the existing hose on your induction hose.
The induction system will then remain clean because any oil from the crank case will drop in to he oil catch tank instead of contmnating your induction system casing harm to your turbo and eventually leading to turbo failure if not treated.
You may wish to consult your motorfactors for a diesel turb cleaner,
Generally an aerosol spray,
It will clean the fins on the induction turbine this will also help your engnes throttle response because it will suck better after the oil has been cleaned.
To complete the clensing,
I recommend you purchase a can of wynne's engine flush fr diesel engines.
It costs less than 8euro a can in halfords,
It helps break down the carbon lumps inside your engine oil,
Put it in 20 minutes before drainng the oil,
It will clean the turbo oil feed vain helping to prolong its life aswell.
Thanks for reading and im glad you got in touch to address these issues mate,
Its early days so we can treat the small issue before it grows to somthing more serious.
Also see my guide on EGR blanking the 1.6TDCi that will also prolong your turbo's life
See here: http://www.fordowner...-16tdci-engine/