Prepare for Adventure – Catch Can R&D, Part 1: Stock Review

“What’s the point?” A question commonly asked by those who see cars and trucks solely as a means to get from point A to point B, from where they are to where they want to be. Those people look at a Ferrari and a Camry the same way. There are speed limits and traffic, so what’s the point of having a fast car? They look at off-road capable vehicles and ask, “What’s the point?” We have roads and highways that get you wherever you need to go, why would you ever want to leave them? What those people miss, however, is that with the right vehicle, every inch of Earth is your road, and any drive can be a journey. No vehicle better embodies that idea than the Jeep Wrangler.


Any Jeep owner knows that one of the greatest rewards of driving a Jeep is that it can turn a simple journey into an adventure. But adventure requires diligence. Leaving the beaten path means tires must be maintained at just the right pressure, differentials need to be properly lubricated, and cooling systems need to be topped off. But, as we’ve seen from our previous Jeep Wrangler projects, the Pentastar engine mated to the new JL chassis needs attention under the hood as well.


While the 3.6L Pentastar has been in the Wrangler for almost 6 years, the latest version in the JL has not changed much since 2012. Aside from the addition of an 8-speed automatic and automatic stop/start, the 3.6L Pentastar is the same as it has been for 6 years, blow-by and all. Much like almost every other naturally aspirated V6 before it, the PCV system of the 3.6L Pentastar is a simple hose connected to the intake at one end and the PCV valve at the other end. As engine RPM increases, pressure from the crankcase opens the PCV valve and blow-by is pulled into the cylinders to be re-burned.


If you’re not sure why blow-by can be a bad thing, check out our article on its effects and how to stop it. To summarize, blow-by contains oil that can foul spark plugs and reduce the effective octane of fuel, making your 3.6L Pentastar less efficient and eventually robbing it of its all-important torque. Nothing ends an adventure faster than a misfire.

catch cans

To combat the effects of blow-by, we develop catch cans that intercept the blow-by gasses. The catch can filters out the oil, fuel, water, and other contaminants from the blow-by gasses, allowing only clean air to return to the cylinders and keeping your 3.6L Pentastar running efficiently. We’ve seen in the past that the 3.6L produces a significant amount of blow-by and that blow-by contains mostly oil. Preliminary testing on the 3.6L Pentastar equipped to the 2018+ JL Wrangler suggests that this generation suffers from the same affliction. In fact, it may be the worst we’ve seen in a long time.

The second time around, we got even more blow-by
Blow-by captured during our 3.6L JK Wrangler Catch Can testing

Keep an eye out for our next posts, where we’ll look at the design of our catch can kit and the surprising results of that testing. For now, feel free to let us know if you have any comments or questions.

Thanks for reading!

2 thoughts on “Prepare for Adventure – Catch Can R&D, Part 1: Stock Review”

  1. How do I sign up for news regarding specifically the Jeep Wrangler JLs? I’d like to be notified when a kit is out.

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