Bmw instructions how do you change the tension rope for the internal head lining on a 2008 328i convertible? we have the new part but can figure out how to install it properly

V8 BMW engine 4.4L and 4.8L have a common problem in drying after burning the valve steam seals in cylinder head, witch cause internal oil leak from the valves to the top of the pistons then the oil burns throw the exhaust valves explain the smoke from the tail pipe.
the issue will continue and will get worse with time until you replace the valve steam seals, $1500-$2500 mostly in labor, a BMW mechanic most have a special tool to do the job with out removing the cylinder heads, it's time consuming.

Catalytic Converter being plugged up will cause overheating,, probably didn't even need the new Heads !

http://postimg.org/image/5ob3l3lux/

Assuming you have a 1996 328i convertible based on your photo as there were no US 96 328is.
It is located at the left front end of the the engine cylinder head under the plastic cover behind the VANOS solenoid next to the top of the oil filter housing. In addition to the new sensor, you will need new metal o-rings for the VANOS line, a new rubber o-ring for the camshaft sensor and perhaps a new socket head cap screw if you round out the internal hex trying to loosen this Loctited screw.
See Figures 1 & 3 at the following Pelican Parts link.
http://www.pelicanparts.com/bmw/techarticles/101-Projects-14-Cam-Sensor/101-Projects-14-Cam-Sensor.htm

Looking at engine from front of car, the tensioner screws into the left side of the timing cover about half way up. You will see the hex head protruding.

Click on the following direct Link. It has the several Serpentine Belt Diagrams on of which matches your 3.4L engine AND options (AC/No AC, Power Steering etc.)

Let me know if this helped...

http://www.2carpros.com/car_repair_information/year/1999/make/oldsmobile/model/silhouette/1999_oldsmobile_silhouette_drive_belt_routing_diagram.htm

If you release the tension on the hose it should fall back to its original position. After doing this, just retrace the line back to the other end. There should be two hoses connecting to it. Plastic will always return to its original position if you let relax.

there is a repair kit avaiable from your dealer and a trimmer will have to install it this is called tension straps.

To set the timing you should turn the No.1 piston to TDC, then turn the cam to where both valves on No.1 are close. The timing mark on the sproket should now be in line with the mark on the cilinder head. With No. 1 still on TDC fit the chain.
After fitting turn the engin a few times by hand to make sure there's not a valve pushing against a piston.