Loud Tick Noise?
 

Hello, I have had my 00 986 2.7L for almost a year now. This has been happening since I bought it.

About every 15 min of driving, I hear a loud tick(One tick). It sounds like it is coming from the front windshield in the passengers corner. Close to the mirror and speaker.

It sounds like a small rock hits my window every 15 minutes. Any ideas? I am pretty sure it is not a rock because it sometimes happens with no cars in front of me. And I have never had that ticking problem with any other car I have driven.

Sometimes it happens 20-30 minutes apart. Sometimes 10 minutes apart. Every 15 min is the average.

It only happens when I am driving at 40mph+, not idling or driving slowly.

Radio on or off? Bad speaker?? Just a WAG.

I am not sure really. But I am guessing it also happens with radio off. I don't remember if the radio is on when I hear it.

There are a couple of electrically operated fuel vapor valves under the fender by the fuel door but they're not loud enough to hear above the engine on my car. Don't know if that's what you're hearing or not. The valves are cycled by the car's computer to test fuel system integrity so they might come on roughly the same time every day if you drive a very repeatable route.

Don't know what it is, but I'm pretty sure I know the noise you're talking about...I hear it in my car as well. Seems to me that I tend to hear it more (maybe only?) on very warm to hot days.

I remember somebody asking about the same thing here, maybe a couple years ago. Somebody had an explanation, but I don't remember what it was. (I have no recommendations as to good 'key words' to do a search with.) I do remember that it was something innocuous, so I've ignored it for over 5 years now, with no unfortunate consequences (at least to this point).

I get it too. I think its the car's different mating areas expanding and contracting....completely normal

I get the same on hot days when the car has been sitting in the sun, then driving with the top down. Assumed it was expansion/contraction as well.