Please read all of these threads.

K+N Filters are a bad idea for diesel engines.
http://www.peachparts.com/shopforum/showthread.php?p=984635

K&N filter topic links thread
http://www.peachparts.com/shopforum/showthread.php?p=1354738


Have a great day.

__________________
ASE Master Mechanic

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D

https://www.boldegoist.com/