Hi,

I have 185,000km on my 2010 LR2, always been serviced before required and hasn't had any drivetrain related issues except the rear diff which was replaced around 110k. Just started having an an issue where when driving (not idle) the RPMs constantly go up and down slightly (a hundred or couple hundred), most of the time it's not an audible difference. It started happening right after I cleaned and reinstalled my reusable K&N air filter, but must be a coincidence. I'm also getting quite a bit of random vibration at certain speeds, but not consistently and shifting isn't rough. Also when downshifting to pass someone/go up a hill, the RPMs are constant and normal. The variation is only happening when maintaining speed with cruise control either off or on. I just drove about 1500km and this was happening the entire time, hasn't seemed to get worse, mileage not affected and power is still as it should be higher up the Rev band. I assume it has to be a sensor of some kind and likely engine mounts? Hopefully not a transmission issue.

Spark plugs were done around 150k and serpentine/idle pulley+tensioner as well as a tranny flush were done last year.

Thanks!

 

MAF sensor?

 

Did you check for codes?

 

First, I would stick a stock air filter in there and see if the rpms stabilize........I run a K & N oiled filter in mine (it came with the vehicle when I bought it).

 

You might also reset the car's computers (disconnect battery, wait ten minutes, touch battery cables together, reconnect battery).

The ECU learns the the right fuel/air profile for your engine, and updates that on a regular basis. But you just changed the airflow a lot so maybe the old fuel/air map isn't right. Resetting the ECU might force it to learn the new map faster.

 

The very reason I will not used oiled filters… (nor are they used on F1 cars). they can muck up the MAF sensor.

 

Well turns out it's just me being an idiot (at least partially), I forgot to re-oil my K&N filter after cleaning it with the spray and rinsing/drying. I had this revelation in the middle of the night for some reason. So the next day I went and bought another recharge kit and oiled it while also resetting the ECU. It's definitely better but not flawless like it was running before. Could the MAF sensor need replacement? Thanks for all the replies.

I used the MANN disposable air filters for a few years but have also used the re-useable K&N filters for years and never had an issue until now.

 

I'd drive it around for a while, let the ECU get used to the new conditions and see if it figures it out.

A dry filter would allow more dust in, so maybe clean the MAF sensor? Although it seems doubtful it could that dirty that quickly.

 

Greetings All,

MAFs need to be spotless to function properly as throttle bodies do.
With an oiled filter you run the risk of “oiling” these surfaces. Then in turn additional crud will stick to it.
Should the state of either air flow, MAF or throttle body be less than adequate, erratic running will follow. Just as PCV, vacuum, O2 sensors…
To get to the bottom of this we really need the codes.

 

In my experience with the K & N oiled filter, I will state the obvious. Do not over oil (it's easy to do because it takes some time for the oil to spread evenly), pat off all excess before insertion, but most importantly, do not use the filter for a few days after cleaning & oiling. I have a used spare dry filter that I swap in until I consider the K & N ready to go. If you end up with codes, first carefully clean the MAF with dedicated MAF cleaner and do not get the cleaner on the electrical plug part of sensor or you will swell the gasket seal. I personally like the K & N because it's a one time purchase. As to the benefits, it just "seems" the engine breathes easier with it. I have the i6.