Air filter

[Gold 'N' Brown]

I have no direct experience of oiled filters, but have read about them fouling up MAFs on plenty of forums over recent years. I do wonder though how much of this is just internet hearsay where people have experienced problems after RE-OILING and putting too much on.

Given that pre-oiling their product increases the production cost, there must be a tangible good reason for companies like K&N to do so. From a common sense perspective I can also see why it is needed. Now I appreciate that sometimes companies get it wrong, but if MAF fouling is a proven risk, wouldn't a big company like K&N acknowledge and act on that? One would certainly hope so, but I know it's not always the case.

So trying to take a balanced view on it, I'd be weighing up the risk of increased internal wear due to lessened filtration (from removing the oil) Vs the risk of MAF damage and cost of more regularly having to swap the part. Given it may take 10s of thousands of miles for increased engine wear to take place (and how would one even determine that it was actually increased compared to if you'd had an oiled, or even OE filter over that mileage?) I would probably take the path of having the un-oiled filter.

[Gold 'N' Brown]

I have run my Merc C320 petrol with twin properly oiled K & N filters for over 60000 miles with no MAF problems whatsoever.
Also my old Vectra and my E30 BMW and others in the past.

How far is the MAF from the filter on those cars?

[hillmangt]

The maf on the merc is straight after the airbox after a ninety degree turn, about 25 cms possibly.
I have two filters in the standard airbox which sits above the engine with a box on each side. Its a V6.
The E30 had a cone filter in a cool box and again about 20/25 cm distance.
I clean them about every 20000mls as they are normally filthy by then.

[MistralS60]

Jamesy, which one (3 ? 5 ?) of those girls you posted on the 'not safe for work' bit is it ? Any spare ?

[jamesy12345]

Jamesy, which one (3 ? 5 ?) of those girls you posted on the 'not safe for work' bit is it ? Any spare ?

I'm not choosy mate, any of them will do the job

[LeeT5]

I have run my Merc C320 petrol with twin properly oiled K & N filters for over 60000 miles with no MAF problems whatsoever.
Also my old Vectra and my E30 BMW and others in the past.

You can't compare a Merc to a Volvo. The MAFs are different as is the air flow to it from the filter. Some cars are prone to it, others clearly aren't. Also, the MAF tolerances will be different too - in the mapping.