Many new cars have direct injection engines because of improved fuel economy, performance and emissions. The fuel is sprayed directly into the combustion chamber of the engine so you get a more thorough fuel burn. The downside of direct injection engines is that because it’s sprayed below the valves, your engine isn’t able to burn off any excess carbon buildup above the valves and up into the manifolds.
So over time, that buildup causes your engine to run rough on cold starts, feels strained when accelerating, can develop vibrations (especially at idle), and your city fuel economy starts tanking. In my case, instead of averaging 22-23mpg overall, it kept dropping down to the low 17’s. My car just felt tired.
The usual treatment is to remove the intake manifolds and with a compressor, blast walnut shells inside. Sounds crazy but it’s true. And it’s recommended to have it done every 30,000 miles or so.
So I took my car to a local independent BMW service center where they said they could do it for about $1,200 because of the labor (I think they even take off the valve cover and replace the gaskets). But, they had a new chemical treatment that they claimed achieved the same result for a lot less money (around $300). It’s called the BG Induction Service. To back up the service, the shop guaranteed results or they would apply the full amount towards a walnut blasting service.
Who could lose with a deal like that?
So does it work? In one word – YES! I could immediately feel the difference. The car revs easily and feels light on its feet, like I just lost 1,000 lbs off the weigh of the car. Accelerating up hills is now effortless. And my city mileage is back up again even though I’ve been driving it harder. I’m over 19 mpg in pure city driving.
Which is an important note – the chemical treatment takes off a lot of junk at first (the mechanic said the stuff coming out of the exhaust was nasty). But the residue continues to work so the recommendation is to drive the car hard for a week for maximum removal.
I can’t believe the difference – my car feels young again.
Life with a BMW 2008 535i 