 
     |
| loud crackling and popping noise (Page 1/2) |
|
kramster32
|
MAY 30, 10:01 PM
|
|
|
I have a 85 GT, When I stop or idle I hear loud crackling and popping (almost like popcorn or static electricity). It only makes the noise after the car has been running at high rpm (like freeway driving) and then come to a stop or idle (at stop lights). No noise or rattling can be heard when I start it or when its running cold. The noise goes away as soon as I start to accelerate again and returns when stopping. Ive checked all the heat shielding, nothing is loose. The noise seems to be coming from the driver side of the car. Any ideas?
|
|
|
|
Patrick
|
MAY 30, 10:27 PM
|
|
Bang the underside of your catalytic converter hard with the palm of your hand (or "gently" with a rubber mallet) and see if it rattles.
[EDIT] Hold the presses! My grey matter churned a bit more and I remembered something I had posted in 2009. 
My auto tranny sounds like a rainstick !
The audio file in that thread is unfortunately no longer accessible, but...
[This message has been edited by Patrick (edited 05-30-2022).]
|
|
|
|
Australian
|
MAY 31, 02:03 AM
|
|
|
I think you have leaky extractors probably a hole in on the firewall side rusted out pipe it will become a fire hazard if you don't fix it.
|
|
|
theogre
|
MAY 31, 02:27 PM
|
|
If Cat/exhaust gets hotter driving is likely making noise as cools off at idle....
Maybe "normal" or signs of big problems. Exhaust usually won't made noise until engine Off.
Exhaust and Cat gets hotter if has problems running rich, lean, etc. and even overheat causing fire hazard.
Run Rich or have Poison Cat can have a "Nuke" Cat heating to 1300°F or more Externally that burns anything near by.
Even messed up timing can heat the exhaust til pipes glow.
Need IR or Thermal Couple to read exhaust temps.
See my Cave, IR thermometer
⚠️ Warning: Not all Thermal Couple are rated to handle high heat even when said K type because of insulation and how made. That's included many K TC come w/ whatever meters.
May need ECM scanner and other tools too.------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)
The Ogre's Fiero Cave
|
|
|
|
hyperv6
|
MAY 31, 03:04 PM
|
|
Being it is after it is shut off it is just the pipe cooling and making the noise.
Any cars in the spring and summer will make pinging sounds as the metal cools.,
If it was doing it while running possible leak.
|
|
|
|
kramster32
|
MAY 31, 09:05 PM
|
|
|
I don't believe its the CAT, it sounds more like this: https://youtu.be/TEFn1sB_XzI and it doesn't happen all the time. Sometimes I don't hear it for a week other times it seems like its every time I get the car up to temp.
|
|
|
|
Valkrie9
|
JUN 01, 05:57 AM
|
|
Detonation, by lean mixture, an air leak, a cracked rubber hose, intake gasket, a screw loose.
|
|
|
|
IMSA GT
|
JUN 01, 06:20 PM
|
|
|
Crazy question, have you pulled over and listened near the intake vent since the sound is on the drivers side?
|
|
|
|
kramster32
|
JUN 28, 06:58 PM
|
|
|
|
|
Notorio
|
JUL 01, 11:48 PM
|
|
|
If it was me, I'd drive the front up on ramps and jack up the rear, including an extra pair of stands for safety's sake, then crawl under the car with an auto stethoscope. It sounds more to me like something rattling against the exhaust system.
|
|
|
