Five clicks in the back

[John_D.]

Especially on damp mornings, anywhere from 2-5 minutes after starting the car, after coming to a stop, there will sometimes be 5 quick deep clicking sounds coming from the back of the car. My guess is an ABS actuation even though the car is stopped. No braking problems, no other symptoms. It's done it for a couple of years now, just curious if anyone else has run into this.

[John D.]

It's caused by rust on you rotor. Your rotors can get a thin coating of rust on them overnight if it is wet out.


edit: I guess I'm the reason you have the underscore in your screen name ;) [img]tongue.gif[/img]

[ January 31, 2002: Message edited by: John D. ]</p>

[John_D.]

Oh yeah, that's right about the screen name, it didn't let me use a space... I thought maybe it didn't like spaces, so I put an underscore in there. This could get confusing somewhere down the line. ?!?!

About the clicking, I'm still confused. The sound doesn't happen until after the car is stopped, sometimes after I've already put it up in park, but still have my foot on the brake pedal. What is going on in the braking system to make that sound?

[knowledgefreak]

have you ever had your differential fluid changed?
Clicking sound will be heard from the differential if they did not add the gm silicon additive.

[John D.]

<blockquote>quote:</font><hr>Originally posted by knowledgefreak:
have you ever had your differential fluid changed?
Clicking sound will be heard from the differential if they did not add the gm silicon additive.<hr></blockquote>

I wouldn't think the rear end would click if he was stopped.


John_D.- I don't think it is your ABS either. If the ABS was triggering you would feel it push against your foot at the pedal. This one has me stumped. I can't think of what would pop like that when you are at a dead stop. You may need to have it looked at, unless somebody else here knows what is going on. Sorry I couldn't help you more.

edit- I just thought of this. Maybe it is due to some suspension movement, ie. spring settling, due to the damp conditions?????

[ January 31, 2002: Message edited by: John D. ]</p>

[Jason]

WAIT A MINUTE!? you mean my REAR END CLICKS LIKE IT DOES BECUASE OF NO GM ADDITIVE!?
youve got to be kidding. ok WHERE do i buy the stuff? kuz its to the point now where its driving me nuts...ALSO did it hurt anything if it hasnt been in there for 6 months?

[knowledgefreak]

if you changed your fluid and did not have the silicon additive that could be your prob. You could just have your diff fluid changed or buy the additive from a gm shop. Some diff fluids already have the synthetic stuff in it so no need for the gm (additive)

[John_D.]

Jason - you definitely need the additive if you have had a grease change. It probably hasn't hurt anything so far. Maybe a little extra wear on the discs, but it's just more annoying than harmful. Even if you still have the factory fill, the maintenance schedule on mine ('98) said to change it out after the first few thousand miles (which I did). That was a one-time thing, then it was supposed to be good for a long time. I did notice my pinion seal started seeping after the change, but not enough to be a problem. After 3 1/2 years the level is still full.

To the rest - thanks for the ideas on the clicking noise. It is definitely something mechanical that is rapidly engaging (the only things I can think of back there are ABS and fuel pump), unless there is also some kind of tank or line valving for vapor. There are always 5 very definite clicks in quick succession (it completes in about 1 second, so the cycling is very quick, like counting to 5 as fast as you can). Weird, but no ill effects that I can tell. After the car has been run once for the day it doesn't happen anymore. It's just the first run of the day, and only if it's damp, and only if I have a stop in the first few minutes, at even at that it is maybe only half the time.

[iceman]

It could be your ABS system checing it self. Some cars do that to make sure that the ABS system works then if it dosent then it will turn on your ABS light. If it only does during your first stop maybe it only test it self every so many hours.

[6Banger]

I experience this same phenomenon. It occurs just about every morning on my way to work, and in just about the same spot when I'm stopped at the light. After that, I don't hear it again the rest of the day. It seems to come from the rear passenger side. I've had the car since '98, so I have learned to live with it since nothing seems wrong mechanically.
But I would love to know what it is.