well i got a 97 with a 4.6 so its got the 2 coil packs and plug wires. i was under the hood with my laptop monitoring temps, and i heard this crazy buzzing sound coming from the drivers side coil pack i think. it sounds like an electric buzz, but its not constant. the coil packs are brand new and so are the wires. everythings tight and all. what could it be?

 

My goodness, that would have to be a pretty hefty buzz to hear it over at least my 4.6L running.

Are you sure it's the coil pack?

 

It is possible you have a plugged or stuck PCV valve. I had a similar sound coming from my truck a few years ago, and that was the problem.

 

well its weird. it sounded like it was coming from coil pack. it was loud enough to pinpoint it to that area. so either the coilpack or the timing chain. and my truck isnt that loud under the hood at idle. and what does a PCV valve do?

 

Positive Crankcase Ventilation, it regulates crankcase pressure created during engine operation. Without it there would be excessive pressure in the crankcase which would cause oil to blow out of the engine. PCV valve were added in the '60s, cars used to have a downdraft tube that would come out of the block and point to the road. Those were outlawed due to oil coming out of the tubes and landing on the road causing a safety hazard.

Typically, if they get clogged they can buzz real loud.

 

This may sound weird,but use the "broomstick" method.....Make sure you stay away from moving parts though....Place the end of the broomstick on the suspect area,and hold it against your ear....Move it around until you locate the culprit.
Looks kinda strange(the wife thought I had lost my mind) but Ive used this method for years,and it works.....

 

At a shop I used to work at my boss had a stethoscope that, instead of a pad-end, had a long steel hollow tube end... and he'd point it around the engine bay until he found the noise's location.

Broomstick can work the same way though, lol.

 

Yeah...we have one at our Avionics shop,it has a plastic tube,as alot of the stuff I work on has voltages up to 45,000 volts,and RF output of 65,000 Watts...you dont want,a metal tube stethescope in your ears probing around with that!