Yesterday a minute after starting the car, it started to stutter and vibrate as if running on 3 cylinders, engine malfunction light came on and textual warnings. Car entered limp mode and rev were limited to 3k.
Solution: full clean, wash and re oil the K& N air filter .
Engine then sounded running fine and no shaking any more.
Reset warnings with Carista, taken for a sound and all was good ! Phew !!
Donât over oil that filter. K&N panel filters should only need reoiling every 100k, cone filters every 50k, unless you live in a desert etc.
I suspect that over oiling the filter is the reason why mass air sensor failures are associated with K&N filters.
These sorts of devices are often found fitted on the big corporate fleets in the US, and I think at one time GM in the US was fitting similar devices to some vehicles/
There are a few studies that show that not only blocked air filters will restrict performance, but that paper filters that are changed too frequently can actually contribute to engine wear, based on how filtering efficiency changes during service life.
The oil from this type of filter is known to sometimes cause issues. Personally I would not use one on a âmodernâ car for this reason.
The over oiling may explain why this has happened less than 9 months after I cleaned the filter.
That time I did it because the Mazda dealer did not clean it as part of the yearly service (they would only replace a standard filter). And I found it was clogged with dirt .
So I may have used too much oil from the cleaning kit. And I have likely exaggerated this time too.
I will clean again in 6mo and use very little oil.
Thankfully the fault is transitory once the filter is clean.
I posted this mainly to point other people in the direction if they have a K&N and the light comes on.
I should have taken a screenshot of the fault read by Carista but it was something about throttle
Some muppet garages will try and airline to clean a K&N, thinking they are doing you a favour.
You drive 200k miles a year?
When you same âlittle oilâ, all that is needed, twice in the life of a vehicle, is a light misting, and let dry before fitting.
If you are driving the normal 10k per year, this frequency of air filter maintenance is, paradoxically, reducing engine service life.
An old air filter traps more particles than a new air filter. But ther is a trade off; as the filter ages, it clogs, leading to a fall in engine efficiency.
in the future I will try just tap and shake the filter to shed some dirt but wonât wash and re-oil straight away.
