i am at a loss for ideas. started happening about a week ago. only when starting, there is a fluttering noise coming from the engine bay. the truck starts right up and the noise stops as soon as the engine starts, so i am thinking it is not the timing chain. however, at 153k, i suppose it could be. anyone else ever have this? it is rather odd, and i want to fix it asap.

98 4runner, 5spd, 2.7l, 153k miles.

thanks

 

vacuum leak? intake leak?

 

yeah, i have no idea. it runs great, starts right up, sound goes away as soon as the cranking is over. if it were either of those, it would be noticable while driving (vacuum), or audible while driving/idling (intake). so i have no idea. i am going to take some audio with the camera tomorrow or saturday. hopefully that will pick up the sound and i will post a link to it.