Mr K

Active Member
Has anyone fitted a K&N air filter, worth doing?
I see they are approx. £60 so just wanted to see if it's worth it.
ta
 
Try googling k+n air filter oil on maf sensor, put same words into youtube and get reading.
 
I am probably going to regret this but mine as been in over a year and no issues
I think it’s definitely more responsive but it’s also much faster when washed and cleaned inside so who knows
 
Oil mesh filters work much less effectively than a paper one, letting much more junk into the engine.
Paper ones are not as restrictive as you might think and cheaper/simpler to replace
 
Not this old chestnut.
A K&N filter allows more air in compared to a dirty old paper filter, however there's almost no different between a clean paper filter and a K&N filter.
However a K&N doesn't filter anything like as well as a paper filter allowing in too much grit, and as an added bonus covers the hot wire in the MAF with oil deposits, causing the wire to overheat and fail faster than it should.

If you want maximum performance, just replace the paper filter every year, and remove the fluffy cover, leaving just the paper element underneath.
 
I've had a K&N on mine for nine years and 90k miles and am not aware of any issues as a result. However, it's past it's best and I'll shortly be replacing it with a standard filter as I don't want to tempt fate with a new K&N
 
video is sales pitch, don't be fooled, K&N filter for the TD4 not only cost 8 times more than a paper filter, it will eventually damage the MAF, therefore you would get 8yrs worth of paper filters for the price of the K&N .
 
I did that and this was the first thing that came up

Project Farm tested air filters a couple of years back, he found the K&N doesn't actually filter that well. He does completely impartial tests.

Have a watch, if you don't mind being shouted at for 20 minutes.
 
If you look hard there's people on YouTube testing particle retention, dyno results etc
There's no doubt that the K&N allows more air though than a paper filter, but this is at the expense of dirt retention, which is the only reason an air filter is there to start with.

On the Freelander1 TD4 engine, the standard air filter is enormous, easily twice the size that it needs to be for the power output of the engine. For this reason the standard filter is more than up to the job, so there's no reason to compromise filtering ability, in the hope of a couple of extra BHP.
 
Try googling k+n air filter oil on maf sensor, put same words into youtube and get reading.
As a mature boy-racer, lets call me a road-racer, the principle of a K&N filter are right up my streer, however Lynall nailed it by citing the damage filter-oil can do to the MAF sensor. Simply put the old oiled-filter design works great on old carburetted or "flapper" Air Flow Meter set ups, but it has no place on a hotwire / MAF setup. On any modern motor where I do still want a "sports filter", I go for pipercross these days, however, the M47 engine design really doesn't need a sports filter. I'm not just saying that as I'm middleaged now, and could thereforebe perceived as having turned into a fuddy-duddy...

The reason an M47 doesn't need a sports filter is because the purpose of a sports filter is to overcome the inherent flow resistances of a stock airfiler, typically this is done by increasing the surface area of a filter, or by changing the filtration media with a view reducing it's resistance to flow. But if you look at a TD4's air filter, it's already jolly-green-giant scale enormous, like more surface area than the filter on a BMW 3 litre twin turbo diesel, which can be mapped to the guts of 400bhp, or more with supporting mods, on a filter that is smaller, and ergo arguably more restrictive than a freelander's filter.

I'm not meaning to stomp on your enthusiasm, but you'd be better served if you stick to normal filters and take the money saved from not buying the sports filter and, put it towards a "Ronbox" (Synergy 2a), or a better remap, or some of the gucci bits from MuddyMods. Silicone turbo hoses would be my first upgrade, the original rubbers will be old and saffy, and one hose near the front right headlight has a habbit of falling onto a screwhead which rubs through it creating a boost leak.
 
There's a reason the standard setup sucks air from outside the engine bay - heat. Better to get good quality filter that fits the standard housing.
 
There's a reason the standard setup sucks air from outside the engine bay - heat. Better to get good quality filter that fits the standard housing.
I believe the OP was talking about a K&N Filter that drops in in place of the stock filter, rather than one of those universal cone type filters, so it would still suck in colder air from outside the engine bay.
 
I know very little about air filters apart from I have changed thousands of them, but can bore you with a story!
Many years ago my Fil had a argument about changing air filters every 8 weeks, and the extra mpg achieved in them 8 weeks would more than pay for the new air filter, so he set about measuring the trucks mpg daily, (they did the exact same run night after night using the same drivers) and he found he was right.
Moving on 60 years, and we only change the trucks air filters annually with zero effect on mpg, sometimes I swear the things still look good.

I change my D3 filter annually, and again the thing always looks like it has done nothing.
 
I bought a car with a dealer warranty and servicing included once. A few weeks after the service (think it was at 50k miles) i had caused to take the lid off the air filter. Standard paper filter, it was black, literally hanging with gunge and dirt.
I went back and questioned it, 'oh the air filter isn't due until 70k miles so we don't check it' FFS
Needless to say, did it myself
 

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