Install a Cheap 165/185 Catch Can

** Only really applicable to the 165 and 185. The 205 is fitted with a catch can as standard! **

 

Is there a name for this type of system?

Yes, PCV - Positive Crankcase Ventilation.

Do I need PCV?

Yes. If you were to run with out PCV then the pressure within the head and crank case will be above atmospheric pressure. Sometimes this will be enough pressure to cause the car to burn oil and smoke as oil finds its way past old oil seals etc...

There is also a small performance increase by having the crankcase under a small vacuum...

Why do I want to install one of these?

This will intercept the "oily mist" generated by the engine and prevent the majority from entering into the air intake.

Why do I want to do that?

It'll stop the intake from being soaked in oil. If the intake gets coated in oil then so will your intercooler, thereby reducing its efficiency. This will also help to reduce emissions, help to prevent the car from burning oil and may also help to prevent detonation.

Tools required

Parts Required


Picture of one of the 2 catch can variants
The cheap catch can. The star indicates the drain for the can
Unplug the AFM, loosen the big hose clip and unclip the AFM from the air box. Remove CAREFULLY from the car. These things are a bit sensitive apparently, and easy to damage
  Loosen the clip that holds the metal elbow to the big turbo intake pipe. Unclip and remove the two small bore pipes from the metal elbow and remove the elbow from the car


At this point, I got curious/nosey and decided to remove the big pipe from the side of the turbo intake. In my case this was a good move. The pipe has a couple of cracks in it and will need replacing AND answered my question of where 'all that oil was coming from' - via PCV and out through the crack. I also discovered some 'non-standard' pipe work between turbo and wastegate. My car had previously been fitted with some kind of boost control (as I suspect a lot of owners may find) that had been partially removed before I bought it. All the 'gubbings' had been removed, but a pipe had been left in place that effectively was feeding none of the boost to the wastegate. Fortunately, I've been sensible in the time that I've owned her, otherwise, I suspect a huge, expensive engine rebuild could have resulted! She now has the standard pipe back in place... for the time being! ;-)
Next step is to establish which of the two pipes disconnected from the metal elbow is the PCV pipe. The one on the top goes off to the back of the engine bay and feeds the Idle Speed Control Valve

The one on the side of the elbow goes away under the intercooler to the other side of the cam cover and into it, and by virtue of the oil inside the pipe, this must be the one!

Cut a length of pipe long enough to reach a suitable mounting point for the can and fit, with jubilee clips, between the PCV pipe and the bottom of the catch can. The can should be mounted with the flat end facing downwards as there is a baffle inside this end of the can
Cut the remaining pipe to a length long enough to reach the metal elbow (when fitted to the car). At this point, the cap came off the top of the can. This isn't all bad news, as it enables you to position the top pipe to give a straighter run to the elbow


Glue the lid onto the can, and fit the pipe between the can and elbow.

The remaining pipe fitting on the can is blanked off inside the can, so it is reasonable to leave it alone, but I will be blocking mine just make sure it IS airtight

Refit all the remaining bits and pieces





Finally installed!

Start car and allow to reach full operating temperature and check for oil and air leaks. An air leak should be quite audible and is normally accompanied by a rough idle


Many thanks to Julian Hankinson for supplying this article