Eventually those EcoBoost engines were going to suffer from all that boost.
Hardly any car on this planet makes it from the design book to the sheetmetal form without being plagued by at least one issue. Engine problems tend to be rare, but given that Ford's EcoBoost technology experiments with horsepower-per-liter ratios that used to be fatal for engines intended for long-term use, technical difficulties are bound to come up. Especially when that engine is only 2.3-liters large and makes 350 horsepower and 350 lb-ft of torque for the Ford Focus RS.
Ford admitted to Autocar that Focus RS' built in 2016 and 2017 were experiencing problems where coolant would burnt get into the combustion chamber and burn while the engine was running cold, causing "white exhaust smoke." The problem has affected cars with as little as 6,000 miles on the odometer. Ford told Autocar that it's, "working on a repair for all customers," a phrase that leaves open the possibility that the fix could extend to cars not (yet) affected by the problem. The spokesman added, "In the meantime, if vehicles show these symptoms, customers should visit their dealer for an inspection and repair under warranty."
While Ford hasn't given a reason for this anomaly, owners' forums seem to indicate that coolant leaks into the combustion chamber because the head gasket doesn't seal to the engine block correctly. Affected Focus RS' don't seem to leave the factory this way, so the current speculation is that the shape of the engine block is being distorted itself as the power plant cycles through various heat cycles. Once the block has distorted enough, the gasket won't properly seal with the head, causing the coolant to leak. One Focus RS blogger even claimed that he found a dealership report backing this theory up, with the report showing that one coolant-leaking car had a "distorted cylinder head" due to a block that was "out of tolerance."
If this ends up being the cause of the Focus RS' mysterious white smoke, Ford's recall could involve costly repairs for the company on both affected cars and those that aren't yet suffering from the problem. Thus far, Mustangs with the same engine are safe since they feature a block and head built from different alloys given that the engine doesn't have to endure the same limits as the RS'. Hey, no one said this transition to turbo performance would be easy.