I have a 01 f4i. it has 17000 miles on it. not to long ago i had the whole 16000 mile service done and had the dealership
put synthetic in it. even before i had the service done, it was making this noise. it doesn't do it until the temp comes up
to normal ( 170 ). people tell me to use a thicker oil but i don't know how thick i can go and still be able to start it in the middle
of winter. i haven't felt a loss of power or anything but it's loud and annoying at the rpm band between 4200-5400.
PLEASE HELP!!!!!!!!!!!!!!!

 

Most likely your Cam Chain Tensioner is bad. OEM cam chain tensioners are spring loaded and when they are worn out or wearing out the dont provide proper tension on the cam chain. I had the same problem a long time ago when my bike had a rattling noise at 4600 rpms or so but it only rattled at that rpm lower and higher rps it was fine so i got on ebay and purchased a Manual Cam Chain Tensioner it was a little tricky to put on, but i found some info on how to intsall it on the web. Problem solved and when i do my vaulve adjustment i will check the tension on my chain and adjust it if needed. Hope this helps good luck

 

incorrect info about the CCT being BAD. The rattling doesnt mean it isnt providing proper tension but rather a two piece desgig causes it to ratle.

-chris

 

i beg to differ because i have seen a CCT go bad on an f4i where the chain actually slapped the chain gaurd, rattled real bad, if it were a bad 2 piece design with hondas part then why wouldnt it rattle from the start. I still say when the CCT loses tension it can hold the pressure of the cain and they rattle.

 

Either way - if it sounds like a tin can of BBs rattling then it's the CCT