Creaking and Crackeling from Under Car (Exhaust?)

[rontek]

Just looking for others thay may be experiencing the same issue. When I am parked with the car running, or right after I shut the car off after driving a while, I hear what to me seems to be an excessive amount of "crackeling" and "creaking" coming from under the car. I assume its the exhaust expanding and or contracting from heat, but I have never owned another car that is as loud as this. My EX has about 9000 miles on it, so the exhaust should be broken in and have burned off any excess factory manufacturing materials by now. Any other owners observations would be appreciated.

Ron

[dividedhighw]

Hi Ron,

I don't have the noise you reported, but I have noticed that there's what sounds like a heat shield rattle from underneath once the car has warmed up. I had the dealer repair it once, but the sound is now back. I'm waiting to see what the warmer weather brings, before deciding if I want to pursue it further.

Cheers,David

[rontek]

Hi David,

I think they are the same sound. I am describing it as a crackle, but it could also be described as a heat shield rattle too. The only reason why I did not think it was a rattle was it only happens when the car is warm or hot, and keeps going after the car is shut off. You would think a loose heat shield would make noise only when the car is running or in motion. Do you know what the dealer did to originally fix the noise? I am going to bring my car in for its 1 year service next month, and I plan to mention it then as well as the steering vibration.

[dividedhighw]

Just to be clear in my case, Ron, the sound is only heard while the car is running. Once it's off, I do get normal "tick-tick" sounds as it cools, but nothing unusual.

Cheers,David

[AWGD8]

I already have that sound eversince I bought my EX. Once I pulled in to the garage and let the car idles for 2 minutes and shut it off, I could hear the sound of exhaust tubing crackling and creaking like it cools off from being expanded...Seems to be a normal thing though... Winter, summer , spring or fall it sounded the same. Could it be the catalytic converter? not sure, but the noise seems to be coming from the exhaust manifold, down to the catalytic to mid pipe... Definitely, not a rattle sound.

http://www.sixthsphere.com/php...&sd=a
Modified by AWGD8 at 7:03 PM 4/22/2009

[EX-lover]

I think many cars have this crackeling sound when engine turn off. Usually more noticable in garage with the sound bouncing off the wall.

[RollerEx35]

I have the same crackling sound on mine, my EX is around 9000 miles too. I think it's a normal sound but it's louder than other vehicles I have driven.

[kamiguy]

Interesting.. I always had the normal cooling sounds when I shut the car off, but after I had the car in for the steering vibration fix, I now notice a crackling noise when I am in the garage, just prior to shutting off the engine. This noise was never present before the steering fix. After the car is shut off, then it's just the normal crackling noise from the exhaust cooling. I will check with the dealer this week to see if any heat shields were removed for the repair and maybe were not replaced properly.

[adam007to]

Interesting.. I always had the normal cooling sounds when I shut the car off, but after I had the car in for the steering vibration fix, I now notice a crackling noise when I am in the garage, just prior to shutting off the engine. This noise was never present before the steering fix. After the car is shut off, then it's just the normal crackling noise from the exhaust cooling. I will check with the dealer this week to see if any heat shields were removed for the repair and maybe were not replaced properly.

What did they do to fix the vibrating steering? I have the same problem and would appreciate the advice.

[kamiguy]

zer...ationgo to the last page of this posting and there is some info posted by our illustrious moderator regarding the part number.

[SteveTheTech]

That is usually a normal noise of expansion and contraction of the new style exhaust system (new since the 07+ G and EX). The benefit of this system is significantly less rust and corrosion (experienced in all older Infinitis) the downside to a thicker exhaust with a different metal composition makes them slightly more likely to make noise as they contract.

[CaribMon71]

I have the rattling sound too. I only hear it when I open the window and the car is on, or when I get out of the car while the engine is still running. I guess it's the heat shield.

[MagicMan2000]

So, SteveTheTech, are we concluding that the crackling sound eminating from the exhaust pipes under the car while the car is running is normal due to the new exhaust system designed to mitigate rust? Like others, I think crackling is normal for a little while after the vehicle is shut off, but while it is running...seems strange to me.

I noticed this week that my EX, too, crackles, while it's running (easily noticeable in a garage with the windows down). I was planning on having it looked at during my next oil change, but if it's normal, I'll forego having the dealer (Infiniti of Chantilly) investigate. Seems a little louder than most other cars I've driven, but...hey, I don't want rust either!

Thanks SteveTheTech!

[302@12psi]

I had a loud case of this the other day. 2008 EX with 6k miles on it.

Drove 20 mins to work all highway. When I pulled into the work and parked with the car running there was a loud crackle noise coming from the car. Reverse and park again and the same noise is there. Turn car off...same noise.

[SteveTheTech]

[QUOTE=MagicMan2000]So, SteveTheTech, are we concluding that the crackling sound eminating from the exhaust pipes under the car while the car is running is normal due to the new exhaust system designed to mitigate rust? Like others, I think crackling is normal for a little while after the vehicle is shut off, but while it is running...seems strange to me.[QUOTE]

As for the normalcy of this incident I have to say yes and no. Yes from the several examples I have heard the noise sounds like normal expansion/contraction of the exhaust system. But I would am reluctant to say that all cases are normal and there may be some people that are hearing a noise and it may be a problem.

Since the V36 (new G) and EX came out they have been using a new exhaust setup. While it appears to have the long term durability that our older systems were lacking, time will be the deciding factor. If the noise persists with the engine off I would not hesitate to say that it is coming from the exhaust.

I have yet to have anyone with an EX bring their suv into my service department with this complaint. Although I am guessing that if they did they would not be able to duplicate the concern or someone would say it was normal without finding the point of origin.

Honestly though I would love to say there is something I could replace on your car that would silence the noise once and for all but it seems like it might be similar to the late 90s Pontiacs, but quieter.

sorry for spelling errors, lack of coffee and work computer=fail usually