This is an old post but a new post came in my email. Knowing what I know now...I have the same car.

When you take the intake manifold off you really should replace the valve cover gaskets too...they will be leaking.

So while you have the intake off and the valve covers take off the timing cover. You will probably see a piece of plastic missing off your timing chain guides like I did. They break due to age not mileage. So I replaced all of them.

Don't wait for the guides to break off and you start hearing the noise.

Bought mine for $6,000 with 85k put 8k into it check all your suspension parts too.

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2002 X5 4.4i Sport Wheels
2014 X5 35i M Appearance & suspension package
1995 Porsche 993
1972 Porsche 914-6
2020 GLE 450 Twin Turbo
2019 Alfa Stelvio 500hp Quadrifogilo
Many motorcycles