My 02 Ford Ranger with a 3.0 v6 starting making the same squeaking/chirping sound. I first thought it was the serp belt or one of the rollers on it. I took the belt off and ran the motor just with the crank pulley running and the noise was still there. I then put the belt back on and used a stethoscope and probed around on the motor until I touched it to one of the 2 screws that holds the black plastic cap on top of the shaft assembly. This is the sensor pick up. The Ford dealer tells me to replace it (about $55 bucks) and the shaft assembly that goes down in the motor and is gear driven from the back of the cam. (about $150bucks). I call a NAPA store and they have a Dorman / Balkamp complete upper and lower unit for about $55bucks. Being the tightwad that I am I took the 2, 5.5mm bolts out, removed the black plastic cap (top), and sprayed the shaft under the little spinney thing with WD 40 with the truck running. The squeak went away and has been gone for a week now with no re-occurence. I don't know how permenant a fix this is. I do not know how it is oiled. If it comes from splash oil off of the cam or what? I was told by the Ford dealer if it locks up it can tear the back off the cam and / or destroy the block.
A little heavier oil might be better, like some atf or 10wt or something.
I also did not really understand how it could run with it disconnected and it did not turn on a check engine light.
Btw: There is a OTC tool that they say you need if you repalce the shaft (lower part). It is different for varoius Fords. It has something to do with finding TDC I think. It is about $30bucks Hipo302
A little heavier oil might be better, like some atf or 10wt or something.
I also did not really understand how it could run with it disconnected and it did not turn on a check engine light.
Btw: There is a OTC tool that they say you need if you repalce the shaft (lower part). It is different for varoius Fords. It has something to do with finding TDC I think. It is about $30bucks Hipo302