Collection: VARIABLE INTAKE MANIFOLDS

Mercedes Benz 3.0 and 3.5-liter V6 and V8 engines (M272 & M273) are fitted with a variable intake manifold that includes a set of long and short runners. Mercedes has used a series of flaps and an actuating mechanism to bridge these runners, changing the distance air needs to travel to reach intake valves.

As it is the case with most intake manifolds, they tend to gunk up over time. We can thank the PCV system for this particular instance, which is a fairly standard affair in these engines. That being said, once the gunk starts to build up, the swirl flap is forced to work against increased resistance.

Given enough time, the flap will reach a point where the resistance is too much. Interestingly enough, it’s not the flap that goes first, but rather the cam lever that activates it. The lever is, you’ve guessed it, made of plastics. The result is a stuck flap and an engine that has suddenly lost its ability to fine-tune intake timing.

The resulting symptoms often include loss of power, misfires, extremely rough idle, engine throwing P2006 codes, and a persistent check engine light.