Tweety Bird in my Engine

Last week, while driving out of a parking lot I started hearing what sounded like a chirping noise coming from the engine compartment. It was intermittent. During the short drive home the noise went away for awhile back came back. It seemed prominent at low speeds. After I got home, I traced the noise with my mechanical stethoscope. All the belt driven accessories sounded OK. I also eliminated anything associated with the drive train because the noise was most noticeable when idling. The chirping sound seemed to be coming from a rotating component. All "vitals" (temperature, pressure, etc.) were OK. No CEL. The noise seemed to be coming from the upper section of the engine in the area of the intake manifold and valve covers. During sustained high speed runs, the noise is much less noticeable or disappears. Now the only rotating engine component in that section of the engine is the CMP (Camsahft Position Sensor) which sits atop the Synchronizer assembly. The CMP provides information that the PCM uses to determine the TDC of Cylinder No. 1. The synchronizer rotates inside a bearing which could in this case could be wearing out. Has anyone experienced anything like this? Other than the aggravating noise, the vehicle runs great.

This is just a follow up. After conferring with Ford mechanics and others on auto websites who experienced the same type problem, I'm pretty sure that the chirping noise was coming from the camshaft synchronizer. I already purchased the synchronizer and will have a mechanic install it as it needs a special tool to ensure the correct cam angle.

I have a '99 Ranger 4.0L engine which I need to replace the camshaft synchronizer. The bearings is worn out so it's making this chirping sound. Although removing the synchronizer itself is simple, getting to it could be a problem. I know that the upper intake manifold and the ignition module have to be removed. But does anyone know for sure if the lower intake manifold have to be removed also, which is a major job. Meanwhile I injected white lithium grease into the synchronizer to lubricate it and the chirping sound went away however, I know eventually it will return.

I'll answer my question. I went to the Ford dealer and the mechanic said I do have to remove the lower intake manifold also to be able to remove the camshaft synchronizer. Labor cost? $500.00. Bummer. It will take over four hours to remove components and about five minutes to replace the sychronizer. But I have no choice. All of you guys experiencing the same problem take note.

are you guys talking about the 4.0 sohc engine? I have an explorer with the sohc engine and on start up on cold days it make the same noise for about 5 minutes.

The chirping noise I've noticed occurs at all temperatures. However, it more noticeable at lower engine speeds. It is also intermittent. But I know it was getting more frequent and time to do something about it. If in your case the noise disappears after 5 minutes or when the engine warms up, it could be something else. I do have a 4.0L SOHC engine. The synchronizer is right behind and below the right valve cover sticking out of the engine block.