Greetings Everyone,

I have a 2005 F150 Lariat Crew Cab (5.7 liter V8) with approximately 76,000 miles on it (I just recently purchased it). It has started to whine at certain times while driving it. Recently on a four hour trip it was whining at around 50-60 mph with the rpm right around 1800-2200. It would come and go but I am not sure what is causing it. The sound is similar to the sound that a wine glass makes when you run your wet finger around the top of the glass. It is a harmonic sound. Every so often it will start just as the transmission is about to shift from 2nd to 3rd. The sound will come and go as soon as it shifts.

Secondly, While travelling on the highway at about 60-65mph I have noticed that if i start to decelerate and then start to accelerate, there seems to be a hesitation/shutter before the truck regains its power. The local ford dealer said they had to adjust the programming on the transmission which made it a little better but it is still there.

I love the truck and it is cosmetically in great shape. Its comfortable and has plenty of power. I am fearful that this noise and hesitation is going to lead to something rather nasty and expensive down the line.

Any thoughts or suggestions would be appreciated. I purchased the best extended warranty at the time of purchasing the truck. I just dont want the thing breaking down while the wife and kids have the truck.

Thanks

 

The hesitation is probably a low grade misfire, indicating you need new spark plugs. They should have been changed at 60k but the previous owner (and the dealer) probably avoided it due to the sticking/breaking issues in the 5.4 3 valve engine.

5.7 is a GM engine, not a Ford engine.

 

The whine/ whistle is from the altenator bearing....it just does that when its cold....

 

It could also be a tired battery, the alternator is whining trying to keep it charged. You can get a free battery and alternator test at most parts stores.

 

Thank you guys. It was the rear bearing in the alternator. The whine is gone with the new alternator installed.

Low grade misfire. Interesting. I will have to check that out with new plugs. It does not do this when you take it out of Overdrive. Only exhibits this behavior when attempting to shift from overdrive to drive. Feels like a transmission problem but I am taking it in on Monday. Thanks again.