Hello all. I am a new owner of an '83 944. I had my mechanic look over the car just to get a second opinion about an issue I noticed. The car starts and runs like a champ. There is a sound that is extremely noticable when the car is idling. When idling there seems to be a sort of "clanking" sound that my mechanic swears is a cracked flywheel. When you give it a little gas (anything over 1200 rpms) the sound is no longer there. Can someone explain what they think this is and if it is the flywheel, why would the sound go away when the engine turns more rpms?

Thanks in advance.

 

Well a couple of things, is your mechanic a porchse mechanic? If your fly wheel is cracked the Centripetal force on the flywheel will make the stress points move as the speed of rotation changes. that would be why the noise quits at higher rpms, but as the stress moves from the cracked area to the good area, this makes the crack lines grow. I cant say for sure you have a cracked fly wheel, but if the noise is comming from that area, it is not something you want to ignore or wait to see if it gets worse. You can pull the starter and look inside the bellhousing to see if you see anything, likely you wont be able o tell, but you may find something else loose.You may need to drog the transmission / torgue tube and remove the bell housing. There is a good procedure for this at http://www.clarks-garage.com/.