The humble catch can. It’s one of those pieces of kit that you hear plenty about, but can’t really determine whether it’s something that you absolutely need.
Well, for 4WDers with a common rail diesel engine, they’re an absolute must. Sure, some owners might disagree, but if they could see what a catch can prevents going in their motor, I reckon they’d change their mind faster than a BMW driver changes lanes. Before we get into it, some more modern vehicles come fitted with a standard catch can. But do your research before you start checking it off your shed list. Not all standard catch cans are up to the task!
What does a catch can do?
You could take care of your engine as well as Kimmy K takes care of her skin and still be the subject of sludge and soot build up in your intake manifold.
Put simply, a reliable catch can will separate oil, soot, and fluid from crankcase gasses. It’s there to protect your intake manifold from sludge build-up, make the recirculated air cleaner, and extend the life of your engine.
Not all catch cans are created equal. When you’re looking to buy the right kit for your vehicle, be sure to choose a catch can that includes a filter. If it’s just a can with an inlet and an outlet that you settle on, it’s not only your hard-earned you’re risking, it’s your motor too. .
Don’t weigh it up. Here’s why you need a catch can
By nature, a common rail diesel engine compresses a mixture of diesel and oxygen for combustion. When that combustion occurs it creates exhaust gases which react with nitrogen, making a pollutant (NOx). To adhere to Australia’s strict emission rules, vehicle manufacturers are required to ensure their common rail diesel engines use exhaust gas recirculation (EGR) valves to send some of those nasty gases back into the engines air intake, where it gets re-burnt during the combustion process.
Sludge build up will still occur during normal engine operation.. Fuel and water can easily make their way into your vehicle’s crankcase where they are then sucked up through a positive crankcase ventilation line (PCV), and pushed through the air intake, where you guessed it, they go back into your engine to be burnt again.
This nasty cocktail of EGR and crankcase gases creates a build-up of soot, oil and sludge in your intake manifold. This results in a noticeable loss of power, diminished fuel efficiency and a healthy bill from your local mechanic. Still weighing up if you need a catch can? You shouldn’t be.
What if you have a petrol 4WD?
If you thought you could get away with not buying one because you own a petrol 4WD. Think again. Directly injected petrol engines aren’t immune from carbon build-up in their intake manifolds either. This means your petrol engine will also benefit from a catch can to aid in removing any unwanted crankcase emissions. Catch cans are easy to install and maintain, to learn more about how to fit one to your 4WD, check out this handy guide below.
The nitty-gritty
Sure, a catch can may not be the most attractive off-the-shelf upgrade for your 4WD, but without one you risk losing a 4WD to modify in the first place. As far as potentially engine-saving mods go, we reckon it’s hard to find one more worthwhile. Installing a catch can will keep your 4WD performing at its peak for longer and your hip-pocket will thank you!
We’re interested to know! What experience have you had with catch cans?
