IRS Clunking???

[NC98GT]

Hey guys, I just traded my 98 GT in for an 03 Cobra and I've noticed a weird clunking noise coming from the rear of the car. It basically sounds like a golf ball is rolling around in the trunk. I only notice it at low speeds. Has anyone encountered a similar problem?? Any ideas of what it could be? Everything looks tight under the car and there is nothing in the trunk to cause this.

 

[Uncle Meat]

Hey guys, I just traded my 98 GT in for an 03 Cobra and I've noticed a weird clunking noise coming from the rear of the car. It basically sounds like a golf ball is rolling around in the trunk. I only notice it at low speeds. Has anyone encountered a similar problem?? Any ideas of what it could be? Everything looks tight under the car and there is nothing in the trunk to cause this.

Does the "clunking" happen when you get off and on the gas ay low speeds? If so that's normal for these IRS equipped Cobras due to slack in the drive line.

U.M.

 

[NC98GT]

It happens even at a steady speed, I would say anywhere under 30MPH.

 

[Uncle Meat]

It happens even at a steady speed, I would say anywhere under 30MPH.

When you get "on" & "off" the gas, yes? That's normal.

Do you mean you can ride along at a steady speed and still get a clunking noise? What if you set the cruise control for 30MPH on level ground, does it still clunk for no apparent reason?

U.M.

 

[NC98GT]

When you get "on" & "off" the gas, yes? That's normal.

Do you mean you can ride along at a steady speed and still get a clunking noise? What if you set the cruise control for 30MPH on level ground, does it still clunk for no apparent reason?

U.M.

I can ride at a steady speed of say 20MPH and I hear a clunking noise for no apparent reason. At first I thought it only happened on bumps, but I noticed it also happened on smooth surfaces too. I'm going to take her in this week and have it looked at.

 

[Uncle Meat]

So, at slow speeds, on smooth surfaces, out of the clear blue sky, it just clunks for no reason? Weird....

U.M.

 

[NC98GT]

So, at slow speeds, on smooth surfaces, out of the clear blue sky, it just clunks for no reason? Weird....

U.M.

Exactly, it sounds like a golf ball is rolling around in the trunk. Very strange. I've never heard anything like it before, but then again I'm used to the solid axle. I let you know what the dealer finds.

 

[Uncle Meat]

Well don't feel bad! I have had a rattle in mine since almost new that I can't chase down. It sounds EXACTLY like the rear glass is loose, at least that's what it sounds like (glass vibrating against metal). The problem is the sound is coming from an area right under the passenger side speaker in the rear package shelf. It rattles whether the rear seats are folded up or down. The rattle is more pronounced when it's cold out and gets quiter as the weather gets warmer, but never goes completely away. If someone sits in either of the back seats, the rattle goes away?

U.M.

 

[Snarf]

I have this same kinda deal with my 99. At first, I thought some guy left a wrench in my vert top. It sounded like a little socket wrnech rattling against glass, or steel. You'd only hear it over sizeable bumps and such.. I've looked all over the back end of the car but I cant find a thing loose thats near the source of the sound. Its coming from directly behind the drivers side passenger seat.. like near the seatbelt receptacle, or the rear sharkfin window.. Its getting to be annoying.

 

[az_r2d1]

I have this too. Sounds like everyone has it.

 

[Xjman1]

Ours did the same thing. Took it to a dealer and they found a loose shock on both front and rear drivers side.

Joe

 

[NC98GT]

Ours did the same thing. Took it to a dealer and they found a loose shock on both front and rear drivers side.

Joe

I'm thinking that is what my problem is too. I just haven't had a chance to look at the shocks yet. I may check that tonight before I take it to the dealer. Thanks.

 

[Rad Ray]

Rear Suspension Noise

I've also encountered the same sound at slow speeds - sounds like a single knock ("pop") independent of road surface, camber, or speed. The sounds did appear after changing the springs (stock to Eibach) and replacing the IRS bushings with some from Steeda. The handling is much improved, but the mechanic can't find the noise source which was thought to be coming from the exhaust pipe contacting the frame - not! I'm returning it tomorrow to the pro shop and will post an update, that is if they can figure it out. An engineer friend thinks it could be the frame straining from previous add-ons (e.g., subframe connectors & braces). I think it might be the shocks being re-installed improperly, but what ever it is, it shouldn't be happening. If anyone else solves this, please post it as I think there are a lot of owners who are just tolerating this.