Hello, First I must say this sight is fantastic. Years ago when i owned a t-bird supercoupe i was a member of the sccoa and this is very reminiscant. Car owners who love their vehicles and are great with sharing info, it's great! Here is a little backround on my vehicle. I just purchased my first cadillac, a 1997 seville sts a few weeks ago, and I obviously love it, great condition, it's near cherry, and the mechanics are working wonderfully. I just have one sort of odd question, as I am somewhat proficient in mechanics and I have never seen this before. I just noticed today that when i reach around 30mph or so, with the drivers window down you can hear sort of a tapping/somewhat quiet knocking from what sounds like my dashboard/control panel. This has baffled me as it does not sound like a rod or anything, and only happens with the window down...also the knocking is in intermintent patterns..maybe 10 taps here, than a couple taps, than a 5 more ect...The ride and performance of my vehicle has not been compromised in any way, and the computer has given me no indication of trouble as far as codes. Has anyone experienced this before, and if so, does anyone have any helpful hints?

thank you

kevin

It could be noise from the sunroof drain plugs being clogged, my car did that until I cleared them anytime I would put a window down, kinda like a glop, glop, glop noise.

thanks, i'll check that out...and yeah..that noise sounds right..sort of like a quiet glopping/popping maybe...sounding somewhat muffled at times...

are the drain plugs right around the perimiter of the sunroof by chance?

oh, i forgot to mention, this may be important...today was the first time we had a heavy rain for 3-6 hours since i purchased the car....i'm thinking the problem coincided with the rainfall maybe.

There should be a drain in each corner. Use a length of .080 dia. weed wacker line to rod them out.

will that cause the water to rise to the top of the roof of the car than, thus draining?

forgive me if i'm a bit slow tonite, i'm not here with the car right now and i need a visual to understand better..maybe in the morning..thank you

Picture a gutter around the inside perimiter of the roof opening with a drain tube at each corner, running down the rerspective pillar.

ahhh..gotcha...so than the water actually runs down into the inside of the vehicle?..either way..i'm bringing a bucket :)

No. The drain tubes run down the pillars and drain underneath the car. The rears can come dislodged and drain into the trunk.
Oh, you meant water leaking past the roof seal. Yeah, it comes in so to speak.

all right..gotcha loud and clear now...hopefully this is the solution to my problem..thanks bud :)