MSD DISTRIBUTOR buzzing

[madmaxx]

Well I reinstalled the distributor, it fired right up. With my $800 ultrasonic listening device I could not determine anything, to sensitive LOL!!! I did find the source of the noise however, once again persistance pays off. The noise occurs between 850 and 870rpm. At that speed the centrifugal weights resonate, if you go above 870 rpm they are quite or below 850 rpm at 860 rpm the noise is constant. I suspected they could be the source when handling the distributor they rattle like a box of marbles when just spinning the distributor by hand. Springs are there, bushings are there, just loose fit by design.

It makes sense I just now noticed the noise. Now that it cold and getting dark early I bumped the idle so that when the headlights, heater and coolant fans kick on the idle doesnt drop to low I bumped the idle up a couple weeks ago just when the noise started to appear.

In the end it was not a bearing, not electrical noise etc. It was "looseness" in the weights pivots".

Thanks for the all the help.


I did find my wind leak on the lexus. The tone generator is cool, you cannot hear it with out the listening device and ear muffs. Turned out not to be the window but the door seal by the front fender, took about 2 mintues to find. Every tool has it place.