Help! Tranny problem or something else?

[W6MIR]

I have a 2003 Explorer V6 w/ about 128000 miles on it. My problem is this, while I'm driving I hear this sound almost like something is blocked in the exhaust. this only occurs at between 2500 rpm and 3000 rpm. Once the truck shifts into higher gears the sound goes away.

The transmission seem to shift fine but I just have no clue what else it could be. The truck hasnt thrown any dtc's but im just so boggled, I also had the alternator replaced about a week ago and my truck didn't have this problem until after the alternator was replaced.

Im extremely concerned and dont know what to do!

Mike

 

[imp]

Speedy Alternators

Gosh, if it seems a noise showed up pretty soon after an alternator is replaced, something else suddenly going haywire and making noise seems highly coincidental, no?

First, look for the serpentine belt tracking improperly on one of it's pulleys. Often, installation allows the belt's edge to be over the pulley's edge. This will soon destroy the belt, and CAN make noise.

Belt tracking OK, take it off, turn alternator by hand, feel for roughness as it spins. Human cognition sensibility in fingertips is amazingly exquisite. If it spins smoothly, it still can have bearing problems which create noise at high speed. Remember, the alternator spins MUCH faster than the engine, maybe 3-4 times as fast. If possible, throw a different alternator on, only takes a few minutes, big problem obtaining one that is fairly new. Bear in mind that if your alt. was replaced with a rebuilt unit, odds are better that something is amiss withy it than would be with a brand new one.

Just a few thoughts here which are surely less expensive than delving into the transmission! imp

 

[jakedrew]

I would loosen the belt, or take it off and see if all the other pulleys spin free. (along with the alternator like stated above).

GOod luck and keep us updated.