Piston Slap: For a Cleaner EcoBoost, Install a Catch Can?

Sajeev Mehta
by Sajeev Mehta

Mark writes:

Sajeev,

I’ve had my 2015 Focus ST for 15 months and 14,000 trouble-free miles so far, and I’m really enjoying the car. The car is still 100 percent stock, but I’ll likely contact Torrie for a tune before long.

As much as I like the car, I’m really alarmed to read about the intake valve “gunk” issues with Ecoboost and other direct-injection engines. It seems as if DI engines have a real problem that the manufacturers really aren’t willing to acknowledge or address (if it even can be addressed).

What’s your opinion on oil separators and/or catch cans? Are they a good preventive measure, or should I just resign myself to funding a cleaning via walnut shells or other similar clean-up tactics when gas mileage starts to dip, power drops, or misfires develop?

Some of the more basic oil separators, such as one from Steeda, cost $65-80, while more elaborate catch cans run $200 or more, plus installation. At that higher price, spraying in a can of CRC’s Intake Valve Cleaner now and then and just paying for a cleaning at some point down the road might not be such a bad choice.

What would you say is the most cost-effective choice for someone like me, who plans to keep the car for probably 80,000–100,000 miles, but probably no longer than that?

Sajeev answers:

The ideal fix is a piggyback port fuel injection system. Toyota’s been at it for a while, with no internet chatter about walnut shell blasting. Since that ain’t happening on your motor (it’s going down on the soon-to-be released 4.8-liter V8), and because it’s turbocharged, consider installing a catch can as preventative maintenance.

Of course, that depends on the application. With a stock tune? Probably not. But after adding more-than-stock boost (via tune, bigger turbos, etc), consider it a mandatory upgrade. Catch cans are simple, cheap (but YGWYPF) and easy to remove/sell if returning to stock for resale purposes — which is highly recommended to claw back extra cash you won’t see otherwise!

What say you, Best and Brightest?

[Image: Shutterstock user Creations]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Sajeev Mehta
Sajeev Mehta

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  • Shedkept Shedkept on Dec 28, 2016

    Porsche has had issues with the SAI (Secondary Air Injectors) on the '96-'98 993 models with OBDII. The '95 can have the problem but there is no "Check Engine Light" since it's OBDI. LOL. DI engines on later models have had issues as well. @sajeev-mehta; I like the Mercury Marauder idea. Cool cars, bullet proof chassis and engine. Police still use the Crown Vic format.

    • Sajeev Mehta Sajeev Mehta on Dec 28, 2016

      Crown Vics are starting to get thin in police fleets in my town...the newest ones are 5 years old now!

  • GeoS GeoS on Dec 28, 2016

    Any comments on using a catch can in cold weather regions? I thought about getting one for my DI engine but it seems they can freeze from moisture and effectively block the PCV function.

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