BMW SWIRL FLAP FAILURE

Full engine rebuilds with 12 months warranty from £3,000.00 + VAT

As BMW owners, we are used to enjoying the benefits of superb design from German car manufacturers. German car makers have set the standard that others simply aspire to. So it comes as a surprise that the car giant BMW could get an engine design wrong?

The BMW diesel engines produced between 2000 and 2006 all have a particular design problem with inlet manifold butterfly flaps (commonly known as swirl flaps). Swirl flaps are used inside the inlet manifold of the BMW M47tu & M57tu diesel engines to vary the length of inlet manifold tract subject to load and anticipated demand. This allows optimum performance to be delivered (on a dynamometer!)

Back in 2000, BMW/pierburg made a decision to manufacture those diesel engine swirl flaps from steel. BMW swirl flaps will commonly fail in such a way that they either: drop an affixing screw and or the upper section of spindle. If this does not stop the engine the remaining swirl flap falling completely in will! The outcome of such failure is not pretty in the slightest. Diesel engine’s piston cycles at least at 60 revs per minute, so an ingested metal piece fallen off the butterfly flap will be slammed by the moving internal components. Most often one or more piston ends up being severely damaged along with several valves, an injector and the cylinder head, with possible collateral damage spreading to the turbo as well?

Around 2004 BMW addressed this fault; the swirl flap supporting spindle was increased in size along with the affixing screw diameter (we have seen vehicles registered up to 2007 with early type 22mm swirl flaps fitted). Despite the increased spindle diameter, we have seen and had numerous reports from customers all over the country of modified type swirl flap failure!


The best solution is simply to eliminate the problem by removing the flaps completely and replace them with blanking plates.

However, if your swirl flaps have been digested then you will require a full engine rebuild which we can carry out for you at a cost of £3,000 + VAT inclusive of parts.