hi guys, Maybe someone can be of assistance Just today i took the 328 for a spinn. nothing fancy, no fast driving. Almost back home I noticed some strange noise. All readings were just fine, engine reved oke, oil temp and pressure oke. at home I left the engine on and opened the engine cover. Everything looked well but the sound was clearly audible and seemed comming from the distrubution-side of the engine. Some history that might be of interest: I just had the engine out for a big oilleakeage. While at it I changed distribution belts and bearings as well as the drivepulleys bearing.I did not change the other belts ( yet, planned to but received the wrong types) After I put the engine back in I already did about 500 km of driving Back to now: as said, the sound was really obvious and kind of ratling and I noticed (by putting a rod of iror to different parts and to my ear) that the sound was clearly most loud at the front belt cover. Also I noticed that, when reving up to about 3000rpm the sound disappeared suddenly . Reving up further did not had it re-apear. But when off the trottle the sound came back again as the revs lowered. My first guess is (as I just renewed both belt bearings and drivepully's bearing ) that it might be (a bearing in?) the alternator. I will remove the belt tomorrow but I do like your ideas on this. Car is a "87 model 328 but with only 26000 km on the odo.
Take a look at your AC hard lines and make sure they are secure. If they are loose they will rattle against the firewall and drive you nuts. Bob
IF your other belts are new/properly tensioned(remember, they are probably PLASTIC, so re-use invites noises when COLD), The coolant pump is either new or re-built, and the Engine was recently out, And, assuming that your cam belt install with bearings was done properly with appropriately correct parts... then... the noise is almost with out question, and i n99% of the cases, going to be a secondary resonance associated with either, or both ,of the A/C lines in 1 of the 2 most Likely places: against the plastic intake horn for the air filter duct, or In the rocker panel box itself... good luck...
What you can do if you do not have a auto stehascope ( spelling ? ) then you can take a old wood broom stick, cut it down to like 2 feet,carefully touch it to different parts on your car then put your ear on it, you will find the cause, , it sounds ancient but it is better than guessing., and works great.
an obscure place to look...if the washers on the top of the a/c compressor between the compressor case and the rubber mount aren't sandwiched in snugly (or stuck in with grease/crud), they can vibrate at certain rpms. The noise transfers through the bracket to the belt cover. the parts manual shows slotted spacers/shims can be in that area too, though I've never seen any in my limited exposure to these cars. Without the spacers, tightening the top compressor bolts enough to clamp the washers usually makes the belt pretty tight, and the idler pulley contributes very little to remove belt slack.
His problem whas a broken ringnut on 1 of the drivepulleys.....glad nothing happend with its belt. Guido
Yes ,indeed sorry to be silence. In fact a broken nut (Yes it was BROKEN) allowed the pulley to come of a little allowing to hammer the axle a little > rattling noise all it took was a new nut. Did 500 km already without any problems. thanks all for the advise, thanks Guido for reminding me to post
