PCV Filters - Symptoms of blockage, why they are a problem and how to fix.
 

PCV filters on our car are a bit of a nightmare - when blocked you may experience a bit of smoke on acceleration (or idling, or conversely you may have turbocharger seal failure or ejection of the oil via the dipstick.

If you think yours is blocked, change it rather than risk more damage.

Common symptoms of PCV blockage include:
- Excess smoke on acceleration or when idling (if severely blocked)
- Oil ejection via the dipstick tube
- Oil around the injector area / elsewhere on the cam cover

Why do they cause problems?
BMW used the PCV as a filter to remove oil vapour from crankcase circulation air before it entered the air intake for combustion - unfortunately it was omitted from service schedules and subsequently neglected on most of our cars.
Most agree changing the PCV at around every 30,000 miles is acceptable, however some choose to do it more often (won't do any harm, of course) to prevent issues arising.

Replacing the PCV
There are a few excellent guides on this Forum for information on replacing the PCV - however the basics are as follows:
- Remove engine cover, and air box cover
- Remove leak-off pipes from your injectors - use needle nosed pliers to remove the metal securing clips, and carefully lift each T piece from its injector
- Unbolt the injector wiring loom holder, and move it and the wires it contains out of the way of the PCV housing
- Remove the bolts holding the PCV housing in place
- Remove and change the filter assembly, also remember to replace the rubber seals which reside in the cam cover and seal up against the PCV housing. There are 2, which should be included with your new PCV filter.

I have the PCV filters in stock: http://www.dmgrs.co.uk/collections/a...-kit-llj500010

Mat