The racket that you descibe when loosing the header bolts - was it a tinny type of rattle, clanking or what. I am still puzzled by the tinny type of rattle I have but with no exhaust gas leaking at the header (used a gas analyser for CO/HC emmisions)it doesn't seem to be this. Was performance effected by the loss of the bolts?

Regards

Ian

AS far as the loudness, these cars are generally loud. The only way to tell if yours is excessively so is a direct comparison. But you may want to take a small mirror and look at your headers where they bolt to the head. The studs have a tendency to vibrate out over time. I was missing two of four from the # 1 header, and one day while driving lost all of them (or the last of the 4 I guess) from the # 6 header, what a racket.

Hello, Both of you seem to be well informed about the M engines, and the M635csi. So here goes.
I have an 85 M635csi that is new to me. My ownership background is an 84 633 and two 87 635csi and have been driving the six series for some eight years. Now the M635csi.. Car has 109,360 kilometers bought it with 106,200 compression is in the measurment of BAR
Cylinder one 13.5 two 12.6 three 13.2 four 13 five 13.1 six 13.2
Never any oil loss or consumption and rear tail pipes are very clean no carbon. This is if I drive it hard or mild.
What I have noticed:
1- the car is load.. trx tires make a hell of a lot of noise. I also think that the headers are a part factor in the noise level? At certian times after inical start up the engine sounds like a dessel. and after a very short while the sound goes away. Could this be due too not enough oil entering the head at start up? Scares the hell out of me. Also at around 2500 to 3000 rpm I hear a little rattle vibration and goes away but only at that rpm. Checked the heat shield and all is thight.
2- After starting the car I must be very careful shifting from 1st to second. This means very slow engaging the gear until it is warmed up never any problems shifting up gears or down from 3rd to 2nd. After it is warm I still must be careful shifting from 1st to second. Direct north to south will result in grind. So I shift with lever after nutral gate a little left of center and it will go in smooth. But I still can't see how I could shift faster without having a grind problem.
Have chaged the trans oil to a 75 90w syenthetic and it helped a bit. The oil that was in there was old and dirty.
Any recomendations Please?
Thanks
Keith