BMW Repair: 1993 BMW 325is, 1993 bmw 325is, engine management computer

Question
About five months ago they ran an inspection report at a BMW
shop. When the report came back it stated that one of my engine
valves was not functioning. The vehicle was making a low, but
annoying consistent knock. Being that I did not have the amount
of money the repair shop required to have the vehicle repaired, I
continued to drive it. Yesterday I was on the freeway and I heard
a loud rattle coming from the engine. I pulled over and the car
was shaking as though it wanted to stop, but didn't. The car has
always had an oil leak, which sadly, I overlooked. I was just
wondering if my valves need to be replaced or calibrated? Could
it be something else? This is the first problem the car has ever
given me, in the year I've owned it.

Answer
Well.....  what it sounds like is one of your valves had a slight bend or misseal and driving it for the amount of time you did, most likely you put a valve into the top of the piston and disabled the cylinder, now the engine management computer has stepped up the idle to facilitate the loss.  Chances are you need a new set of pistons, a complete valve job with all new valves and possibly a new cam.  but for moneys sake you'd be best off buying another engine from a junkyard for a few hundred bucks.
You can do a compression check and a leakdown test on the cylinder you think is at fault, this will tell you how well the cylinder is holding a seal.  you will most likely haveto take the head off to see the extent of the damage.
let me know what happins.
-cheers
scheidmiwa@hotmail.com