When I start my truck, in the morning and then in the afternoon, after sitting at work, it makes a really loud sound like a baseball card in bicycle spokes. once the idle comes down, usually between 30 and 90 seconds, it goes away. my mechanic is a little perplexed...can anyone provide some help? Whatever it is, it isn't affecting the performance at all...

 

It sounds like the kind of noise you would get from your heater/air conditioner blower fan. Leaves and debris tend to get into the housing and the fan blade flapping against eaves would make that noise.

 

It sounds like the kind of noise you would get from your heater/air conditioner blower fan. Leaves and debris tend to get into the housing and the fan blade flapping against leaves would make that noise.