Hello all,
I have a chirping noise that has been developing over the last couple of months. At first it was nothing more than a very slight chirp at idle. You could only hear it if you were standing next to the truck. It over time got louder and louder. For a while it was only doing it on cold mornings but now it does it all the time. It is pretty constant, but only at low rpms. I replaced my alternator a few weeks ago so I can rule that out. I had the belt off the other day and spun the idler pulley by hand and it spun without any resistance. It didn't make a chirping noise but more of a slight scuffing? noise if that makes since. Could this be my problem? Btw, I have a 97 4.6 5 speed with 277k. The water pump, fan clutch, belt, and tensioner have been replaced in the last 50k/2 years.
Thanks!

 

I want to add, when I spun the idler pulley it probably did 6+ rotations before it stopped.

 

Chirping usually stems from the first converter and it's heat shield. That's what it does when the spot welds begin to fail. It chirps at low idle, -more so when in D with foot on the brake. Ford has a TSB on this issue.

 

Its completely random when it chirps. Sometimes it chirps for 5 seconds then stops, sometimes it chirps non stop until I start driving again. At idle its pretty loud. I can hear it with my radio on. Is the best way to check the heat shield just to physically wiggle it with my hand?

 

And I do have a slight exhaust leak on my driver side. Maybe the two are related. I'll check it out this evening and report back.

 

Nope, that won't work. The Ford TSB states that you have to use band clamps around the shield and tighten. I've done it before. The chirping stops, but only lasts for a few years or until more spot welds break. Finally, I just replaced everything to solve the problem. Since it's annoying as hell lol.

 

I just got to take a look at it. I have ruled out the heat shields. Its definitely coming from the front of the engine. I took the idler pulley off because it is for sure shot but I don't know if thats where the chirp is coming from. I believe its either the idler pulley, or possibly the harmonic balancer. When I was looking at it just now it would only chirp once ever thirty seconds or so. Just one chirp. Strange.

 

Could be the fan clutch...my 05 does it when its cold...took forever to figure it out. Then one day when I shut the truck off it continued for a couple of seconds...spun the fan and it chirped...

Sounded like a couple of baby birds under the hood...For what its worth?

 

Thank you for your input! I actually changed it not to long ago and it seems to still be functioning normally. It doesn't spin freely when I spin it by hand like my old one did. Whatever is making this noise does however sound like a couple of baby birds...pretty loud baby birds haha

 

Try replacing the idlers then.....

 

You can use something like a long screwdriver to stethoscope the noise while it's occurring. The noise will transfer to your ear and be more pronounced the closer you get.

But yea, tensioner and idler pulleys do go bad. Tensioner's should always be changed with the belt. Idlers go bad probably the most. Fan clutch, lasts for ever as well as the others. If the Fan Clutch does go, there's usually traces of fluid leakage around bearing.

 

I replaced the idler pulley and the engine is much quieter now but the chirp remains. While replacing the pulley the stud that the bolt goes into broke off! :O i applied 35 ft lbs as instructed by another online thread and it broke. I got a longer bolt from homedepot for a temporary fix. Any ideas on a permanent fix? Also, i discovered my P/S pump has about 1/8" in/out movement. Is this normal or is it time for a new one?

 

Just take my advice and find out what's chirping. It's not that difficult, honest lol. Anything will work to transfer sound.

 

I'm sorry I didn't just follow your advise! I felt like the biggest idiot, and still do, when the perch broke off. I think it is just attached to the timing chain cover so I guess i'll be going to the junkyard to find another one...until then, I hope the half inch of threads I have left is enough to hold the pulley on.

I really do appreciate the input you have given so far! I just jumped the gun and made a mistake.

 

Make sure the chirp is not a sparkplug getting ready to launch. What do you mean by a perch...do you mean the front cover pulley boss broke off?