Swirl Flap Modifications
The BMW inlet manifolds on certain diesel models have swirl flaps which are designed to create a swirl of air to improve combustion under light load and to reduce a slight increase in emissions from soot due to a lack of air. The flap is closed by an actuator during light load, idling and fully open during engine load to maximise air intake and increase engine output.
The problem with swirl flaps is that when they fail, the rivets/screws can get sucked into the engine causing damage to pistons, valves, cylinder heads and damage to the turbo.
BMW swirl flap failure can result in a repair bill of several thousand pounds and there are many reported incidents of BMW swirl flap failure on the internet costings thousands of pounds worth of repairs.
BMW introduced an improved and stronger swirl flaps to address the issue in 2004, however there have been reports of the newer design failing and this obviously becomes more of a risk as cars start to come to the end of their warranty.
Here at Ayrshire BMW and Mini Specialists we offer a modification to prevent this from happening, which is not available at your local dealer! It involves replacing the flaps with swirl flap blanking plates, which ensures this problem will not occur and will not effect your vehicle performance. Models affected are most variants of 3 Series E46 Diesel, 5 Series E39 Diesel and 5 Series E60 Diesel.
Modification Call 01292 262040 or email