The synchronizer shaft for the camshaft position sensor can cause a loud squeak or chirping noise due to failure of the upper bushing. The noise may be erratic and is usually present when the engine is warm.Google+
Car Problem Reports
Ford Ranger Synchronizer Shaft For the Camshaft Position Sensor May Make Noise
Ford Ranger Problem
Engines Affected: 3.0L V6, 4.0L V6
Average Mileage: 95,773 mi (60,000 mi - 150,000 mi)
Visitor, 2001 Ford Ranger, 3.0L V6, 90,000 mi
Synchronizer Shaft for camshaft position sensor upper bushing goes bad and makes squealing sound like a loose belt (replace)
Had the intermittent squeaks. Mechanic diagnosed it immediately. Replaced synchronizer and sensor. No more squeak, but 'Check Engine Light' is not always ON
had the same problem friend works at ford, found, and fixed the issue quickly...part is expensive trough ford...aftermarket part is 1/4 of the price.
Visitor, 2001 Ford Ranger, 3.0L V6, 93,000 mi
chirps when the engine is warm.
chirping sound at random times with the engine running.
Visitor, 2003 Ford Ranger, 3.0L V6, 120,000 mi
something in the engin "churps" when the engin is warm
Visitor, 2002 Ford Ranger, 3.0L V6, 73,500 mi
Loud chirping/squeak when engine is warm, erratic. CPS or synchronizer.