Hi all-- this is a re-posting of some messages buried in responses to an inquiry about engine noise in a 740t (http://www.brickboard.com/RWD/index.htm?id=466394). I'm re-posting them for visibility, and since three different people are hearing what seems to be the same thing, I'm wondering if anyone can help us out. I've posted questions about this here and on the Swedishbricks before, but thought it might be a belt/pulley/water pump/alternator/or fan noise. It is none of those, definately. Details are below:

jddaigle writes (http://www.brickboard.com/RWD/index.htm?id=466753):

"I've been chasing a similar issue in my 89 745GL for a few months--it makes a noise at idle that isn't belts, pulleys, or water pump/alternator, but won't go away. My question is, does piston slap sound like a clicking or a chirping? My sound is a loud chirping that comes and goes, becoming more constant as the car warms up, definately coming from the engine, somewhere in the area of the head. It's actually loudest if you kneel down next to the right front wheel, and either disappears or gets drowned out above 1000rpm. It's an eternal mystery!"

aargilb writes (http://www.brickboard.com/RWD/index.htm?id=466714):

"I have a 87' 740 Turbo and it makes the exact same noise. I always was told that "piston slap" gets quieter/goes away as the engine warms up. Mine does exactly the opposite(gets louder). Noises sound like they are coming from the valvetrain, but all valve clearances are within spec. I am fixing to have the head rebuilt and will let you guys know if it works."

eadlermn writes (http://www.brickboard.com/RWD/index.htm?id=466735):

"I have an '89 760T that makes the same noise. When I was changing the timing belt I noticed that when I turned the camshaft, it would turn, then "click" into the next position. I'm thinking that my noise is due to that. *I'm also hoping it's a normal noise..*"

-Eric