hey guys.
well, the ol' girl is doin something, and I'm hoping ya'll can help me isolate the issue.

Clicking noise. Don't know what, where or why. You can only hear it when your sitting in the seats with the doors closed. Is an obvious clicking noise(at least for me, not a usual engine noise) It doesn't increase with RPMS at all, doesn't stop or start with the fans running. And as soon as you open the door it gets drowned out. suggestions? thanks guys

dose it sound like the sound is comming from near the passangers feet area?

seems to be more localized toward the top of the dashboard. maybe toards the middle? I will try to confirm an exact or localized location tomorrow moring

aside from a punt to the top. I have localized the clicking noise to be loudest in the middle front. Almost near the radio and AC/heat controls.

Do you have a tape player? I have seen them get stuck think they have a tape in them.

nope. aftermarket CD player thingy with an aux plug in. but I believe the noise was there before that went in.

defroster vent motor?

Do you have a video camera? If so shoot a short video around the inside and/or outside of your truck. Get as close to the noise as you can. Maybe then we can help you diagnose this problem.

Without a short video all we are doing is playing roulette. If we figure out the culprit of the noise, it is all out of luck.

the defrost door motor is on the left end of the heat box mid way up. It looks like the same type as the recir door motor. And I have see those click.

Good point DieselCash. I'll see if I can make a decent video or at least a sound file tomorrow when shes running. I'm limited to my camera phone and its not the best but hopefully it will suffice to figure out what that sound is.

For what its worth, I've had a ticking noise since I've owned the Suburban. Since I bought it with 168,000 miles on it about 8 months ago I have no idea if it was there when new or not.

It is most noticable at idle, seems to come from the left side of the engine bay but could easily be under dash instead. It almost sounds like a small exhaust leak but I'm pretty sure its not. I have a feeling its just diesel engine noise, maybe valves. I'm not concerned about it unless it increases.

Any chance you are hearing a kind of echo of the lift pump? I realize its under your feet but maybe the sound seems to transfer to the dash. Would make sense, nothing else would affect the noise, it wouldn't change with engine speed. Just a thought.