Rodents in E320 Bluetec Air Filter Entry Tube


I had put mothballs under the hood and it looked like the problem had been solved - until yesterday while I was doing other under the hood maintenance and just for the heck of it decided to inspect both air filters, which currently have around 9,000 miles of use, and found the passenger side filter probably 75% packed with what looked like 90% seeds and little bit of other junk.
Whatever rodent had been there, was using the air-entry tube as a place store food, but there was no nesting.
The driver side filter was very clean and had only minor debris from normal driving!
I believe there is a hidden trouble with excessive clogged air filters on these Bluetec engines in that clogged filters will cause excess oily crankcase fumes being sucked in by the turbo into the intake manifold through the crankcase pressure control (or bleeder) valve.

I will put in some type of metal coarse screens in to prevent any rodents from entering in future.




That said, I advise, especially for diesel a filter minder.
You can buy 1 with switch, who can be wired to light on dashboard, but just mechanical indicator under the hood can save you potential problems and money by replacing filters when they need it, not by judging from coffee grinds, or mileage.


That said, I advise, especially for diesel a filter minder.
You can buy 1 with switch, who can be wired to light on dashboard, but just mechanical indicator under the hood can save you potential problems and money by replacing filters when they need it, not by judging from coffee grinds, or mileage.
Thank you, addition of filter minder is a good suggestion and I will see what is available.
Anyone here who has done it on these 3.0 Bluetec engines, if so photos would be appreciated?
However I think 20,000 mile air filter change interval should be sufficient for these engines when driving in normal conditions (subject to keeping out rodents)!
By adding 'metal coarse screens' above, I meant adding them to the two engine air inlet tubes!
Last edited by arto_wa; Jan 15, 2023 at 10:38 AM.




Than driving my bus in Baja, the bucket-sized air filter clog after 10,000 miles.
Mileage-based changes suck big time.
Other way to determinate filter contamination is to weight it and compare to new one.
Last edited by kajtek1; Jan 15, 2023 at 12:25 PM.


I had to replace the regulator two years ago but there was no obvious indication of trouble, other than a very minor external oil leak from it, and some excess oil in the turbo inlet.
Yes I know there will always be some oil in the turbo inlet!



