I have an 04 f150 fx4 with 79,000 miles. I have a squeaking problem coming from under the hood that I need to fix now because I am going insane. I have had the truck since 62,000 miles and the squeaking has always been the same. If the truck sits in the garage overnight it does NOT squeak from under the hood, but if it sits outside overnight or sits during rain and then I start it up the damn squeaking starts. After a long drive it seems to quit (like something is drying out?). To me it seems to be the timing belt because it coincides with how much throttle I give the truck. Could it be the timing belt or one of the pulleys? Why does it only happen when it sits outside overnight?? It doesnt sit outside very often but when it does this squeaking drives me crazy! It makes my truck sound like ****! Any input is appreciated!

 

I had this exact same problem and it drove me insane!! I took it to the shop and they put a new drive belt on it i believe, and it fixed the problem. Hope that helps man!

 

Change your belt to a Goodyear Gatorback. Problem solved.

 

thanks guys I will try a new drive belt. BUT can anyone explain why it does NOT squeak if it sits in the garage overnight, only when it sits outside??

 

Humidity, moisture will cause the belt to sqeak

 

While awaiting what Stealth said to do, Soft Soap the belt... see if it helps.

 

IROC,

could you explain what you mean?

 

The belt will make the same sound if your water pump/ac/alternator is stuck. Seeing as how this sound goes away, you can try some belt dressing or the new belt. Should be it. I dont know how much a new belt would be.