Piston Slap: Tight Focus on Engine Break-In Procedure?

Patrick writes:Sajeev,Thanks for the column and the sage advice, but mostly for the generosity as lemons perp. (FYI Piston Slap queries don’t count as bribes – SM)Recently purchased a Focus ST, and though I have rebuilt/broken in conventional engines in the past, new car recommendations of oil changes at 5,000 miles plus and no mention of an engine break-in procedure leave me nervous. Especially with the new breed of HO turbo motors. I know better than to push the motor for the initial 500 – 1,000 miles. Reading forums and interwebs, a number recommend an initial oil change at 1,000 to clear out the initial break in filings, then adhere to a 5k oil change schedule with synthetic fluids.What say you? Running the initial fluids to 10k sounds like an introduction to premature wear to me.Sajeev answers:Engine break-in procedures are pretty simple: RTFM, always keep the tach in the black, and vary your RPMs while cruising. The Focus’ owner’s manual will likely say the same, anything extra is ritualistic practice from a concerned owner. Modern engines have fantastically tight tolerances, etc. so don’t sweat it.Oil changes as per owner’s manual are always recommended, going a bit overboard isn’t a bad idea on a higher performance, turbocharged mill…especially if you get the ECU tuning bug.I’d do the 1k mile oil change if it’ll make you feel better (or if RTFM demands it). I did that when my 2011 Ranger hit the magic 4-digit number because the dealer gave me a free oil change voucher, at 5k I switched to a full synthetic. From there I went to 8-9k change intervals and never looked back. But a Duratec Ranger isn’t exactly a Focus ST.Odds are you’ll be more than fine with the 5k interval: do an engine oil analysis to learn if you can extend the interval, or ensure you don’t fall prey to the sludge monsters of recent memory.[Image: Michael/ Flickr ( CC BY 2.0)]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.