Crankcase Breather and Oil Separator in OE Supplier

An emissions part: the PCV, which when it fails gives oil consumption, a rough idle, a whistle and a set of lean codes, and which is a tenth of the price of the piston job people are sold instead.

We are an independent parts supplier. We are not Volkswagen, Audi, Seat or Skoda, and we are not appointed by any of them. Those are their trademarks and what we sell are parts that fit their cars. The useful thing about this group is that four badges share platforms and share parts, so the same component fits a Golf, an A3, a Leon and an Octavia and costs four different amounts at four different counters. We list it once, at one price, and tell you which platform it belongs to.

Specification and fitment

• Fits: Golf Mk5 Mk6 Mk7 Mk8, Passat B6 B7 B8, A3 8P 8V 8Y, A4 B8 B9, Leon 1P 5F KL, Octavia 1Z 5E NX, and the other group cars on the same platforms with a diesel engine unless the part says otherwise
• Platform: chosen above. This part is shared across the group. The Volkswagen, the Audi, the Seat and the Skoda all take it, it is the same component in four different boxes, and the price here is the same whichever badge is on your car. Choose your badge above for your records, not because it changes anything.
• Engine: 1.6 and 2.0 TDI, EA189 and EA288, plus the TSI engines on the breather parts. This group changes specification mid production and does it on a platform basis rather than a model year basis, so two cars registered the same week can take different parts. Send us the VIN with the order and we check the part against the build data before anything is dispatched. It takes two minutes and it is the difference between a part that fits and a return.
• Production dates: 2008 to 2022 depending on platform
• Quality: made by the firm that supplies the group, in that firm's own box rather than a dealer box. Same casting, same line, and on a group that shares parts across four brands this is where the saving actually is
• Part number: cross referenced to the group part number for your VIN and confirmed before dispatch. We do not print one number against a listing that covers several supersessions, because on this group the supersessions are the whole point
• The failure this addresses: A blocked particulate filter is almost never the filter's fault. It is short cold journeys, a failing differential pressure sensor, a leaking injector, a faulty EGR or a regeneration that keeps being interrupted. Replace the filter without finding the cause and you will have the same problem and a far lighter wallet.
• Labour time: one to five hours depending on the part
• Coding: a basic setting or adaptation is required after fitting, which is a five minute job with a proper diagnostic system and is not possible with a generic code reader. A new particulate filter needs its ash mass counter reset or the car keeps calculating from the old filter's history
• Also needed: gaskets, clamps, coolant where the EGR cooler is disturbed, and a low ash oil to the correct specification
• Torque: exhaust clamps to the figure and evenly. An uneven clamp warps the flange and the leak will stop regenerations happening
• Interval: not scheduled, but the oil is, and a diesel with a particulate filter needs a low ash oil. The group's long life servicing regime stretches the oil interval on the basis of how the car has been driven. It suits a motorway car and it is actively bad for a car doing short cold journeys, which is most cars. A great many tired engines in this group are tired because they were serviced to the long life schedule in town. Switching to the fixed schedule costs one extra oil change every two years and it is the cheapest thing you can do for one of these engines.
• Weight: approximately 1.2 kilograms
• Warranty: two years or 24,000 miles, whichever comes first
• Find the cause: A blocked particulate filter is almost never the filter's fault. It is short cold journeys, a failing differential pressure sensor, a leaking injector, a faulty EGR or a regeneration that keeps being interrupted. Replace the filter without finding the cause and you will have the same problem and a far lighter wallet.
• What we will not sell: We do not sell particulate filter deletes, EGR blanking plates, AdBlue emulators or emissions defeat software. They are illegal on a road car in the UK, they are an MOT failure and they invalidate insurance. Everything on the emissions pages here exists to make the system work, not to switch it off.
• Cleaning against replacing: a filter blocked with soot and ash but not cracked can be cleaned off the car for about a third of the price of a new one, and the cleaning service is on this page
• Cleaning an EGR valve: worth an afternoon on a valve that is just sooty, and a waste of one on a valve whose spindle has worn. The difference is whether there is any side play in the shaft

What arrives

• the part as described
• gaskets, clamps and bolts disturbed by the job
• copper grease where the fasteners will come off again
• instructions with torque figures and the reset procedure

Fitting

One to five hours. On a new particulate filter, reset the ash mass counter afterwards, or the car keeps calculating regeneration timing from the old filter's history and regenerates far too often.

Which version to buy

We do not sell particulate filter deletes, EGR blanking plates, AdBlue emulators or emissions defeat software. They are illegal on a road car in the UK, they are an MOT failure and they invalidate insurance. Everything on the emissions pages here exists to make the system work, not to switch it off. Given that, two questions save real money. Does the filter actually need replacing, or can it be cleaned off the car for a third of the price. And what blocked it, because a filter fitted without finding the cause blocks again within a year. A blocked particulate filter is almost never the filter's fault. It is short cold journeys, a failing differential pressure sensor, a leaking injector, a faulty EGR or a regeneration that keeps being interrupted. Replace the filter without finding the cause and you will have the same problem and a far lighter wallet.