How to clean the crankcase ventilation system?

[kilou]

Hi,

the Haynes manual of my Volvo S40 recommend to clean the crankcase ventilation system each 45'000km by simply blowing compressed air through the hose that connects to the throttle body on the air intake duct. Is this really sufficient to clean such a system or is it alternative ways (and more efficient ones maybe) to clean that system without having to dismantle everything (I would need to remove the intake manifold to gain access to the oil separator etc...)?

 

[The_Jeff]

I'd imagine a little throttle body cleaner would help. Maybe do that and then follow with the compressed air then run the car to burn off all that oily mess before it redeposits.

 

[moribundman]

I don't think that fast-evaporating carburetor cleaner will deteriorate rubber and plastic as long as the contact is only for a short time. I've cleaned out the breather hoses, valve cover wire mesh filters (solids/fume seperator), and the plastic plenum (intake air silencer) with carburetor cleaner without any ill effects. Another option would be electric contact cleaner, which is usually safe on plastic. I like to use that type cleaner on my idle control valve, which does remain wet with cleaner for a prolonged time. However, I have always removed the components that I was going to clean. You may want to remove the throttle body for a throrough cleaning from both sides, as there is likely plenty varnish around the butterfly valve(s).

 

[kilou]

Does the TB cleaner attacks the rubber of hoses?