93 5.7 Suburban 4x4,


Pulled upto the shop last night, shut it down & Tap, Tap, tap abt 10 or 12 times coming from under the dash down where the heater fan & air box is. Sounded just like one of the kids had run around the other side tapping on the door for a laugh otta me.


Cranked it back to the tune of the same riddle abt the same # of times. Grand daughter says, there is a little man in there with a little hammer & she may have it right, who knows?


You know, just when you thimk you've seen/heard it all?


Today, same thing every time it starts up or is shut down!


Yes I know, if I'd just leave it alone it wouldn't do it but the thing don't have but 184k mi & i'm trying to get it broke in maybe.


Anyone else had a hammer in the heater? Not a fan noise.


Thanx, Gben

My freind has the same noise he has a 92 chevy pick up it sounds like a little plastic door shutting real fast. He looked into the problem and it is a vaccum line that has a hole in it. This line close the vent I believe.Comes from the passenger side under the glove box.

Thanx 03duramax1,


Just when I was thinking abt putting it up for sale the little critter shows up. Fine machine in every way & I guess had no business thimking like that. Of that one is a 92 most likely the vaccum line is the culprit. But still would like to have a later model Sub diesel!http://www.dieselplace.com/forum/smileys/Cool.gif


Thanx agn, Gben

It turned out tobe a little door actuator behind the heater fan.


When trying to open or close the gears would skip a cog & slam the door, what a racket for such a small item.


Has one ordered & says it's not expensive but he is not a stealer!


Thanx, Gbenhttp://www.dieselplace.com/forum/smileys/Cool.gif