Replace valve cover gasket on 1998 626 i am worried about tearing up the wiring harness that is over the top of it because its brittle any suggestions?

take off the little plastic cover on top 4 bolts take out the coils mark them remove the wiring harness out of the way then take out the valve cover bolts don't forget the 2 on top of the cover the rocker cover is ready to come off there is also 2 hoses on the rear of the cover has to be removed

If you are feferring to the valve cover gasket, Just remove the cover and replace the gasket. You may need to remove other hoses and disconnect wiring harnesses to accomplish the removal of the cover.

Could the smoke be coming from the exhaust manifold on the passenger side of the engine? When the valve cover starts to leak, it is common for the oil to leak down and burn on the outside of the exhaust manifold.
Replacing a valve cover gasket is not difficult or expensive, and it is common for BMW valve cover gaskets to get brittle and shrink and start leaking every 10 years or so. My wife's 330 needed a new valve cover gasket at 6 years.

LOCATED UNDER THE BLACK COVERS ON TOP OF THE VALVE COVERS YOU HAVE 3 PLUG WIRES AND 3 COIL PAKS YOU HAVE TO REMOVE THROTTLE BODY TO REPLACE THE ONES ON PASSENGER SIDE AND BE CAREFUL NOT TO BREAK THE THROTTLE BODY GASKET AS THEY GET BRITTLE YOU ALSO WILL NEED TO REMOVE THE SIDE BRSCKETS THEY ARE SILVER 12 MILIMETER BOLT AND 1 14 MILIMETER GOOD LUCK

will try to help.if it's only the valve cover leaking,i'm guessing they sold you the rubber one that says ne rtv sealant needed. take your back off, try not to break the rubber seal when removing!clean the top of head where gasket goes. clean the valve cover really good!clean the grooves out that the gasket slides into. buy some blue trv glue, apply a thin coat to top of head, let it setup while you apply another thin coat to valve cover, let set 10mins. apply gasket to valve cover making sure to push the gasket into the grooves on valve cover. don't worry about neatness. let the valve cover set on a hard surface with the gasket against the hard flat surface[such as a garage floor,or clean driveway] after10 more minutes install the valve cover,make sure and take your time. place valve cover onto motor,than hand start each bolt to insure thay are going into the prope bolt holes. after you have each bolt hand started, start at center of valve cover snugging the bolts down to motor. do not crank down or apply excessive force when tightening those bolts. you should see some of that blue rtv glue coming out around the valve cover when applying torque to the valve cover bolts. only secure them snug at first. let car set for 15mins. start car and look for leaks around the cover, do not over tighten those bolts but you may need to look for a leak, go to bolt closest to leak and turn it 1/4 at a time until leak stops. but if you do this step by step, you'll not have a leak issue. you may have pinched the gasket when you replaced it. hope this helps and thank you for choosing fixya.com

The valve cover gaskets needs to be change to stop the oil from dripping down on the plugs. A new plug wire or clean it with a solvent.. Good Luck!!!

Were the valve cover gaskets and harnesses check? May have a wiring harness or valve cover gasket issue where the harness plugs into the gasket

The valve covers installed on the 3.0L engine incorporate integral (built in) gaskets which should last the life of the vehicle. Replacement gaskets are available if required.

1. Disconnect the negative battery cable. Disconnect the ignition wires from the spark plugs, but leave them attached to their wire looms.
2. Remove the ignition wire separators from the rocker arm cover attaching bolt studs with the wires attached, then lay the wires out of the way.
3. If the left hand cover is being removed, remove the throttle body assembly, the PCV valve and fuel injector harness stand-offs. If the right hand cover is being removed, remove the engine harness connectors, fuel injector harness stand-offs and air cleaner closure hose from the oil fill adapter.
4. Using caution, slide a sharp thin blade knife between the cylinder head gasket surface and the valve cover gasket at the four RTV junctions. CUT ONLY THE RTV SEALER AND AVOID CUTTING THE INTEGRAL GASKET.
5. Remove the integral gasket from the valve cover gasket channel. Note bolt/stud fasteners locations before removing gasket for correct installation. Clean gasket channel and remove any traces of RTV sealant.

To install:

1. Align fastener holes, lay new gasket onto channel and install by hand. Install gasket to each fastener, seat fastener against cover and at the same time roll gasket around fastener collar. If installed correctly all fasteners will be secured by gasket and not fall out.
2. Install valve cover to the engine, lightly oil all bolts and stud threads. Apply a bead of RTV sealant at the cylinder head to intake manifold rail step (two places per rail).
3. Place the valve cover on the cylinder head and install attaching bolts and studs. Tighten the attaching bolts to specifications.

Fig. Fig. 3: Rocker arm cover installation on 3.0L engines

1. Install all remaining components in reverse order of removal procedure. Connect the ignition wires to the spark plugs and reconnect the negative battery cable. Start the engine and run to normal operating temperature, then check for oil and vacuum leaks.

most likely it is the valve cover gasket. it covers the valve train where there is alot of oil to lube the top of the motor. if the head gasket was leaking it may have more signs of running poorly. also having coolant leaks also. so i will have to say valve cover gasket. now usally you may have a oil burning smell with it depending on the area of the lek but not always.

the valve cover can easily be seen when the hood is open. it is right on the top and where it meets the clyinder head is where the gasket is and the leak can be seen.

if you have more question please ask.

no, not a blown headgasket, remove the valve cover and inspect the spark plug hole seals(tube seals in the valve cover) replace if brittle and old. also change the valve cover gasket since u have it off...adjust the valves as well