A few dumb questions...

[smdimjesus]

E53 06 x5, 150k miles. I've had the car for maybe 2 years and put 50k miles on it. I've had some bad oil leaks but have replaced valve cover gasket (got most of it) and I'm currently doing the oil filter housing gasket (hope thats the other issue). I've also done the CCV, although I'm not sure one of the lines is properly secured. I'm going to try and diagnose the residual leaks by myself, but any input is appreciated. Some oil has also appears ontop of the upper intake boot and around the DISA valve.

My goal with the vehicle is to ensure its longevity, if you can, suggestions of any crucial parts to replace at this mileage would be appreciated, I've replaced so far; rear rotors, all brake pads, spark plugs, both belts, upper radiator hose, valve cover, manifold gasket cover, DISA O-ring, fuel injector o-rings, throttle body gasket, upper intake boot, fuel filter, and the bank 1 sensor 2 O2 sensor.


I've always noticed quit a bit of oil residue under the hood, but after changing CCV and OFHG it has become apparent that there is a very substantial amount. Its bad. My alternator was completely covered and there was sludge inside to, the power steering pump and pulley was horrible as well. There was actually oil inside of the cooling hose for the alternator. I couldn't even see the hose itself or any components related to it as they blend in. Everything on the right side of the engine bay next to the intake manifold is absolutely caked. Is there anything there that requires dire attention for cleaning or replacement?


1. What are some key components to replace under the hood at 150k?
2. Has the soiling of the engine bay called for additional replacement parts?(if not already necessary to replace at this interval)
3. How do I remove the caked oil residue?
4. What are the negative consequences of allowing this build-up going to be?


If there are any questions I will try to answer promptly and clarify, apologies if my post is formatted poorly. and as always thank you in advance.