Why are they so important?
Turbo Diesel Motors have a exhaust gas re-circulation system, where a portion of the exhaust gas is recycled back through the motor.
This isn’t a massive issue except your exhaust gasses have carbon in them. When this black soot mixes with an oil mist it sticks!
Without a catch can, your engine gets caked up with a sticky black mess and then becomes badly restricted.
The Catch Can sits between your crank case and the positive crankcase ventilation line (PCV) and separates the fluid and mist from the air that makes its way through and catch it in the bottom of the Can.
A simple solution is to install a catch can. Diesel Care™ Provent® Catch Can Kits will make the job easy.