I got a call this afternoon from my wife saying that she was hearing what sounded like faint popping coming from the left side of the engine while it was running. When she got home, the popping disappeared, but there is a low pitched rapid chirping coming from front cam pulley/timing belt. Does anyone know what could be causing this?

 

I just checked it again. It sounds like its coming from the timing belt idler pulley.

 

What year and engine type, V6 or 4 cylinder?

The timing belt would have 2 idlers and also turn the water pump.

Popping and chirping sounds like a bearing.

Make sure is its not a component turned by an external belt such as used for the alternator, power steering, etc.

If is is not one of these components might be the water pump or an idler. Either require removing the timing belt cover (and belt) to change.

Use a section of hose as a stethoscope to run down the area. Water pump is near the water pump hose inlet from the radiator.

 

Changing the idler requires removing the cover. If you go this far change the timing belt and maybe the water pump.

How many miles on the engine. When was the timing belt last changed?

 

sorry for the lack of info. its a 97 v6, 116k miles. the sound has diminished some. i have no idea if the timing belt has been changed

 

The WP and idlers should be good for more miles then this. The industry recommended belt change is 90K miles.

Belts can last a long time, say 150K or longer but they do break. The engine will be OK but you will need a tow.

Check for noise at the air conditioning clutch.

There may be a sticker on the timing belt cover stating when it was changed.