rocky 0 Posted May 17, 2007 Hi Guys, Again, another question! My 205 mi16 has the plastic cambelt cover and the cambelt along with water pump, and cambelt tensioners were replaced about 10,000 miles ago. At exactly 2000rpm i hear a scraping/rattle sound from under the cambelt cover. This noise only happens at 2000rpm and it goes away if i put some pressure ontop of the plastic cover. Also, the noise disappears once the engine has warmed up (about 5 minutes of driving). I have been on the BX forum, and they have said that this seems normal for the BX 16valve engine, as when cold the belt is a little loose and will rub against the cover, but when compenents are warmed it will stretch and therefore the noise goes away. What puzzles me is why does it happen only at 2000rpm and not at any other rpm? Share this post Link to post Share on other sites
Rob_the_Sparky 9 Posted May 17, 2007 Probably generates the right frequency of vibration to excite the belt. At certain frequencies the effect is amplified (resonance) hence will move further and touch. Rob Share this post Link to post Share on other sites
rocky 0 Posted May 17, 2007 Probably generates the right frequency of vibration to excite the belt. At certain frequencies the effect is amplified (resonance) hence will move further and touch. Rob This explanation sounds reasonable. Although it is not a whining sound but a brief rattly sound. However, do you think this will cause the belt any damage or excess wear? I am trying to drive round the noise by shifting the gears to miss 2000rpm - just until i am reassured it is nothing major. Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted May 17, 2007 I have been on the BX forum, and they have said that this seems normal for the BX 16valve engine, as when cold the belt is a little loose and will rub against the cover, but when compenents are warmed it will stretch and therefore the noise goes away.Surely the belt will stretch more when its warm & be tighter when cold? I had a scrapping sound at idle on my old 309 SRi that was the lower cambelt cover catching the crank pulley which only made a noise at idle. Magically fixed when the cambelt was changed next. If you think it might be something else, surely its best to take the covers off & check rather than drive around it? Graham. Share this post Link to post Share on other sites
rocky 0 Posted May 20, 2007 Hi Graham, Yep i should not drive round it, but the cambelt cover seems diffuclut to get off, as there doesnt seem to be musch space for a screwdriver or torx driver. Also how many screws need removing and from where? Thanks Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted May 22, 2007 Also how many screws need removing and from where? http://www.stuartmcguire.co.uk/pug/GB/405F/0/03C20A.HTM Graham. Share this post Link to post Share on other sites
rocky 0 Posted May 22, 2007 I cant get my head round how i will fit a scredriver to undo the screws, it is so tight with space by the cambelt cover! Share this post Link to post Share on other sites
pug_ham 244 3 Cars Posted May 25, 2007 The allen screw you need to access to remove the cover are above by the rocker cover or there is a bolt underneath by the lower pulley, the rest is held in place by a quick release slide bar in the middle of the cover which clips into the studs on the engine. Graham. Share this post Link to post Share on other sites
