x3 3.0i

[Brentolovich]

has anybody de cat their x3 3.0i and seen consumption decrease, if so to what degree?

 

[Blue Shirt]

In my experience, you will see far better improvement in fuel consumption if you replace the VANOS seals on that motor than a de-cat.

What mileage is on the engine? If anything over 100000km, the VANOS seals are most likely worn out. This will make the car feel lazy and increase the fuel consumption as the VANOS is not working properly to advance the valve timing.

I speak from direct experience on my wife's X3 3.0i. You can read up on the VANOS seal problem on these M54 motors on beisansystems.com.

 

[Brentolovich]

In my experience, you will see far better improvement in fuel consumption if you replace the VANOS seals on that motor than a de-cat.

What mileage is on the engine? If anything over 100000km, the VANOS seals are most likely worn out. This will make the car feel lazy and increase the fuel consumption as the VANOS is not working properly to advance the valve timing.

I speak from direct experience on my wife's X3 3.0i. You can read up on the VANOS seal problem on these M54 motors on beisansystems.com.

cool thanks, i did see some threads on the forum saying that the vanos seals (o rings) are often the cause and need replacing.
i am not too mechanicy so is it a big job?