Hi everyone. I am new here, just getting the hang of this computer stuff and joining forums devoted to the stuff I like.
I have a 2003 Ranger with the 3.0 liter engine. It has been a very reliable truck without any major issues, it still runs fine but has an under hood noise like crickets chirping, starts about 2200 rpm and gets progressively louder as the rpm increase. I have not been able to track it down, nor has a Ford dealer or the local independent shop.
The frustrating thing is the use of a stethoscope does not work to isolate the noise, it seems to be coming from everwhere. Ford changed the cam sensor, they thot is was the bearing, not! It's not the PCV valve nor anywhere in the air system.
Anyone have a clue?
Thanks, JG

 

I know it sounds too simple, but could it be the belt? I used a belt dressing on cars before and it really smoothed out the noise right away.

 

My guess is a U joint going bad or a wheel drum warped, if they still have such things. CV's go bad but they make a kind of crunching sound. I suppose a wheel rotor could cyclical squeek, but only at relatively slow speeds.

get someone to drive around you in a parking lot to hear it from the outside so as to locate whence the noise comes from.

 

My mustang does that but its coming from the steering wheel

 

Do you hear the "crickets" when the vehicle is sitting still with the engine running? I had a u-joint go bad on my f-150, but it was more of a squeal.

Like stu37d said, try some belt dressing. I saw that you can't tell, where it's coming from, but I wonder if it could be a water pump bearing or fan clutch.

 

I had the same problem with my 2002 3.0L. Changed the serp belt and the idler pulley, and it turned out to be the cam synchronizer. You can hear it with a stethoscope; it’s in the middle of the top of the engine back near the firewall, looks like a small canister. If that is what your dealer already changed then I may be wrong.

 

My thanks to those who posted a reply.

The cricket noise is not in the running gear anywhere as it will occor beginning at approx. 2200 rpm even when the truck is standing still. Occurs under engine acceleration only, will instantly stop when the throttle is released. Seems like it should be easy to track but such is not the case as we have tried what appears to be everything without success.
JG

 

Given your input about the rpm & the noise going away off throttle, I'd look to the serp belt & the belt driven accessories.

My Taurus "cricket" chirp under those condtions, turned out to be the idler pulley bearing, with ever so slight play/wobble.

Could also be a weak spring in the belt tensoner, letting the belt slip, or maybe it's pulley bearing going dry, or a water pump bearing as has been suggested.

Anyway I'd concentrate my trouble shooting up front with the serp belt & it's belt driven components & with the stethoscope & see if you can isolate the suspect.

The way I found the Tarus problem, after replacing the belt didn't fix it, was to remove the belt & inspect all of the pulleys for damage, or contamination & spin all of the belt driven components by hand, to carefully listen too & check for bearing noise, or play, or roughness.
The bearings should be snug when turned, with no wobble, or in/out play & the pulleys should be smooth & without oil, grease, or coolant on them, or the belt.

The belt tensioner if ok, should show on it's molded in scale, that the belts tension is within range.

More trouble shooting thoughts for consideration, let us know what you find.

BTW Welcome to FTE!!!!

 

Exhaust leak? If you blew an exhaust gasket, they can sound strange. I would look around the flanges, and any other area where 2 pieces join together, if it's leaking there should be some soot deposits near the leak. Just a thought...

 

Since it does not seem to be drive train related, I'd also point my finger toward the belt, tensioner and accessory pulleys.

Remove the serpentine and start the motor. Only run it a short time since you will not have a working water pump and listen for the cricket-effect.

If you don't get the cricket-effect, it could likely be that tensioner pulley's bearing. Grab it by hand and see if it has and slop in it. It should only spin freely and not have any twist to it.

Also check to see if the belt is tired. Look for deep cracks and any wear from old age.

 

Check your fan belt

 

Thanks to everyone that took the time to respond to my question. I have been away and not able to follow up on the suggestions but will be doing so hopefully this week. I will post results here.
JG

 

Removed belt and took for short spin, still there, still sounds like high pitched crickets, starting at 2000 rpm and getting progressively louder as rpm increases. Stops instantly when throttle released.
It is definitely under the hood, seems to reverberate off fire wall and sounds like its everywhere. Can not pinpoint with stethoscope. Very frustrating, have checked every possible moving part, looked for exhaust leak, looked for intake leak, had intake off, valve covers off, nada, end of my patience. Local shop no longer wants to see me coming. I'd sell the damned thing cheap just to get it out of sight but who would want? Runs perfectly so I guess I better get used to it.
Thanks for your suggestions.
JG

 

OK, good test & feedback, so it's not one of the belt driven accessories.

Seeing as how it's a 3.0L & you say the sound seems to be bouncing off the firewall, maybe suspect the cam sensor, as it resides back there on the passenger side, where the distributor used to be & it has a reputation for being squeeky on the Vulcan 3.0L!!!!

Let us know what you find.

EDIT: WOOPS I see in your first post that the cam sensor was replaced by the Dealer!!!!

 

Another thought, did this problem come about suddenly, after some event????