Leaking Valve Covers is a common problem for all 6 and 8 cylinder E39 BMWs. This DIY covers the M62 V8 engines of the E39 540i and 535i.The 6 cylinder engines follow a similar method but have specific instructions. The cause of the leak is that the rubber that the gasket is made from ages and hardens, and stops being able to seal between the head and valve cover. The solution is simple : replace the gasket correctly and the oil will stop leaking. Detecting the issue is simple – usually it manifests as an oil drip onto the garage floor and an obvious ‘hot oil’ smell when the car is parked after use. E39 engines do not leak oil when all gaskets are in good order and they should not smell oily. However, an oil leak can come from anywhere – so you need to visually confirm the leak is the valve cover gaskets. This is easily done by checking the surface of the head on the side and lower surface above the exhaust heat shields. & ...
Fuel pumps can be a common replacement item on any car, including E39 BMWs. Symptoms of a failing fuel pump can include hesitation and loss of power under wide open throttle, difficulty starting or unexpected stalling. If you are unable to start a car and suspect fuel delivery, you can reach underneath the car in front of the rear wheels on the right hand side of the car, and thump the bottom of the tank with a piece of 2x4 timber or similar. If the fuel pump is faulty it may jolt it into life and you have confirmation.
Most BMWs are sold with an attractive set of alloy wheels and low-profile tyres. These look great but few cars escape the dreaded ‘curb rash’ - scraping the wheels on a concrete curb while parking. This usually starts on the passenger side wheel but in cars which have been roughly parked it will often spread to all 4 wheels (and sometimes the spare!)
If you have an Air Conditioner blowing warm, there's a number of things it could be. It's typical for people to brush it off and say 'it just needs a recharge' - well, if that's the case you have to ask why it needs recharging. Unlike older AC systems which had porous hose and inefficient joints, the AC in an E39 uses barrier hose, R134 refrigerant and high quality connections and o-rings. In other words, they don't leak unless there is a problem. You can certainly try refilling the system with gas - if you get cold air afterwards, you know that low gas was the problem - but the length of time the cold air lasts for might be measured in days rather than months or years.