Sean's Blog

Direct injection engines seem to be all the rage today, and for good reason: you can bump up the compression ratio (compared to port injection) without necessarily raising the octane requirement, and/or combine it with forced induction to get higher HP/torque numbers while maintaining or even improving fuel economy compared to a similar engine with port injection.

My 2010 GTI has it, and I’ve been very happy with the engine’s performance. But when I look at the images in links like this one, I do get a little worried. And I’m hardly alone in that regard. This happened with the 2.0 FSI motor, it’s happening with the 2.0 TSI motor in my car, and it’s apparently happening in a wide variety of other engines from other manufacturers (BMW’s N54, various Porsche engines, et cetera).

In a car with port injection, this wouldn’t be a problem, as the fuel would wash over the valves upon injection, but in a car where the fuel is injected directly into the combustion chamber, that obviously has no chance of occurring.

Volkswagen recommends oil changes at 10,000 mile intervals, but after reading about this quite a bit, I can’t see myself ever going that long. I changed my oil yesterday with a quality synthetic 5W-40 at 4,900 miles or so, and I’ll probably be doing every 5,000 miles from here on out. Oddly, for all the crap Toyota has been getting lately, they have seemed to avoid the direct injection problems by pairing their direct injection with smaller port injectors that periodically send fuel through the intake manifold to wash the valves off…