If you're tired of seeing that "service perform" message on your dash, a crankcase filter delete 6.7 Cummins might be exactly what you're looking for. It's one of those modifications that most diesel owners eventually stumble upon after getting frustrated with the high cost of routine maintenance or, worse, finding a pool of oil sitting in their turbo compressor housing. The 6.7 Cummins is a workhorse, no doubt about it, but the way it handles crankcase pressure from the factory leaves a lot to be desired.
For those who aren't familiar with the technical headache, the stock setup uses a closed crankcase ventilation (CCV) system. Basically, as the engine runs, pressure builds up in the crankcase. That pressure contains oil mist and blow-by gases. Instead of just venting that stuff into the air like the old 5.9 Cummins used to do, the 6.7 routes it back into the intake. The idea is to burn those vapors off for emissions reasons, but in practice, it just ends up coating your turbo, intercooler, and boots in a thick layer of oily grime.
Why People Make the Switch
The main reason most guys look into a crankcase filter delete 6.7 Cummins is to stop the "oiling" of the intake tract. When you pull off your intake horn or look at the cold-side intercooler boots on a high-mileage truck, they're usually soaked. This oil doesn't just sit there; it degrades the rubber boots over time, making them soft and prone to blowing off under boost. It also coats the intercooler fins, which can actually hurt your cooling efficiency over the long haul.
Then there's the filter itself. That big rectangular box sitting on top of your valve cover isn't cheap. Depending on where you buy it, you're looking at a chunk of change every 67,500 miles—or sooner if your truck sees a lot of idle time. By deleting the filter, you're essentially removing a maintenance item and a potential point of failure. If that filter gets completely clogged and you ignore the warning lights, the pressure has to go somewhere. Usually, that "somewhere" is through your rear main seal or other gaskets, which is a much more expensive fix than a simple delete kit.
How the Delete Actually Works
When you decide to go through with a crankcase filter delete 6.7 Cummins, you're essentially converting the system from a "closed" loop to an "open" loop. Most kits come with a few basic components: a block-off plate for the intake connection and a new breather setup for the valve cover.
You'll remove that bulky factory filter element and replace it with a plate or a specialized cap. Instead of the blow-by gases being sucked back into the turbo, they get routed through a hose. Most people run this hose down the side of the engine and vent it toward the ground, much like the "puke tubes" on the older 12-valve and 24-valve engines.
It's a simple mechanical fix. No more oil in the turbo, no more expensive filters to buy, and the engine gets to breathe a lot easier. You might notice a slight "diesel smell" standing near the truck at a red light, but for most Cummins owners, that's just the smell of a healthy engine.
The Messy Reality of the Stock Filter
If you've ever taken apart a 6.7 Cummins with 100k miles on it that still has the stock CCV setup, you know how nasty it gets. The oil mist mixes with the soot coming from the EGR valve (if that's still intact) and creates a thick, black sludge. This sludge builds up on the grid heater and the intake valves.
By performing a crankcase filter delete 6.7 Cummins, you're cutting off half of that equation. Even if you're running a completely stock emissions setup otherwise, keeping that oil out of the intake is a massive win for the longevity of the engine. It keeps the MAP sensor cleaner, which means the ECM gets better readings and the truck runs smoother. It's a small change that has a huge "trickle-down" effect on the rest of the engine's health.
Installation Tips and Tricks
Installing a delete kit isn't exactly rocket science, but there are a few things to keep in mind so you don't end up with a mess on your driveway. First off, make sure your vent hose is routed correctly. You want it to have a nice, downward slope without any "dips" or "traps." If oil collects in a low spot in the hose, it can freeze in the winter or just block the airflow, which builds up pressure back in the engine.
Another thing to think about is the hose length. You want it long enough to vent under the truck so the oily mist doesn't coat your front axle or suspension components, but not so long that it gets caught in the driveshaft or melted on the exhaust. Zip ties are your best friend here. Secure that line well, and you'll never have to think about it again.
Dealing with the Dash Lights
Now, here is where it gets a little tricky for some folks. The truck's computer expects to see that filter there. Depending on the year of your truck and the specific kit you buy, you might get a "Service Perform" light or a "Crankcase Filter Full" message even after you've installed the delete.
Most high-quality crankcase filter delete 6.7 Cummins kits include a way to trick the sensor or a plug that handles the electronics. If you're running a tuner, you can often just clear the maintenance reminder or turn off the monitoring for that specific sensor. If you're doing this on a totally stock truck without a tuner, just be prepared to do a manual reset of the service light (the old "brake and gas pedal" dance) to keep the dings at bay.
Is It Worth It?
From a pure mechanical standpoint, the answer is almost always yes. Any time you can prevent dirty, hot oil from entering your turbocharger, you're doing the machine a favor. Turbos are precision instruments that spin at incredibly high RPMs; they don't exactly love being coated in crankcase gunk.
The only real downside is the environmental aspect—which is why these kits are often labeled for "off-road use only"—and the occasional drip of oil on your driveway if the engine has a lot of blow-by. But honestly, compared to the cost of a blown turbo or a leaking rear main seal because of a clogged filter, a little drip of oil is a small price to pay.
Final Thoughts
At the end of the day, a crankcase filter delete 6.7 Cummins is one of those "set it and forget it" mods. It simplifies the engine bay, saves you money on filters every year, and keeps your intake tract looking like it did the day it rolled off the assembly line.
If you're someone who plans on keeping your Dodge Ram for the long haul, taking care of the CCV system is just part of the deal. Whether you go with a basic vent-to-atmosphere kit or a more complex catch can setup, getting rid of that factory filter is a solid move for anyone who actually uses their truck for real work. Just grab a basic tool set, a Saturday morning, and you can have this project knocked out before lunch. Your turbo will definitely thank you for it.