LMM and K&N: Problems & Solutions

Hi,

Following your advice, I removed the mass airflow sensor (LMM) from my wife's 'KOCH-tuned' 110hp TDI (Seat Cordoba Vario).

It looked bad. It was completely covered in a thick layer of black soot. The grille towards the air filter was also black and no longer metallic. I removed the last grille, which is closer to the turbocharger, entirely.

I sprayed the entire thing with electronic circuit board cleaner and abrasive cleaning pads, then blew it off with compressed air – following the instructions.

Now the car is working really well again - you have to hold the steering wheel firmly, otherwise it will go in the wrong direction.

The moral of the story:

Remove the K&N filter – it's not good for the engine. It doesn't actually do anything beneficial.

Greetings.
research; investigate; look into; explore; scout around

open or flat?

Regarding open air intakes from K&N, I haven't observed anything negative related to that issue so far. If there is a problem, I suspect it's more likely due to a malfunctioning PCV valve (Positive Crankcase Ventilation).

Hi,

It is (or rather, it was) a plate air filter.

It's not really surprising. Just take a look at the K&N filter and hold it up to the light. There are many places where you can see through it.

Of course, it's clear that dust and dirt can get through.

I then found the dust in the mass airflow sensor.

Greetings.
research; investigate; look into; explore; scout around

cherche wrote:

Take the K&N filter and hold it up to the light. There are many places where you can see through it. Of course, it's clear that dust and dirt can get through. I then found the dust in the mass airflow sensor.

Here's a remarkable fact: since all airflows always take the path of least resistance, a significantly larger proportion of unfiltered air is drawn through the holes than would be expected based on the ratio of the hole area to the total filter surface area.
The result inside the engine, which is likely a paste-like substance, is probably quite unpleasant... I think it's time someone sued a manufacturer/supplier of such filters for damages related to their replacement engines!

Hi Ulf,

In my 530d, I removed the cotton filter after only a short time because the car had noticeably less power and torque with it installed.

It felt like choking when the carburetor is malfunctioning .

It's probably due to the arrangement of the mass airflow sensor (MAF) relative to the air filter. The air filter looks like a long tube (so it's not a flat plate). The air filter is positioned parallel to the engine, running lengthwise in the car.

At one end, the mass flow meter (MFM) is directly connected. Apparently, the flow through the JR filter was not optimal, which led to a loss of performance.

Through experience, one becomes wise .

Greetings.
research; investigate; look into; explore; scout around

Hello,

"I've had my TDI for 5 years now, and I've been using the K&N filter for just as long. I haven't noticed any negative or positive effects on the TDI itself; it mainly benefits my wallet. Since I live in a rural area, the air filters tend to get clogged very quickly in spring and summer, so I used to have to replace the paper filter every two months. With the K&N filter, I just wash it out and it's good to go. Also, I drive past a cement factory with a filling station twice a day --- sometimes I even pull a concrete-filled air filter out of my car."
If you can see through the K&N filter, something is wrong. I experienced this with my Polo 6N and had to have it replaced by K&N. Currently, we use K&N air filters in four vehicles (a Jetta1 GLI, a Lupo 1.0 with a chip, a Golf Kombi 1.8 90PS, and my TDI), and we've noticed a slight decrease in fuel consumption in the gasoline-powered cars.
I generally cannot recommend this filter to anyone without knowing their specific needs! The decision to choose a K&N filter is very individual and should be carefully considered.