Loud pop at idle - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

damian559 · 08-20-2015, 07:13 PM

I already asked this question and nobody on here knew so figured I'd ask again to see if anyone can help me out. My car will sometimes make a loud pop at idle almost sounds like a backfire. It happens so randomly and infrequently that my shop has no idea what it is either. It only happens every 2 or 3 times I take it out. The car doesn't feel weird and it still dynos the same numbers it did before. I recently put the car on a lift and checked the headers and mid pipes for any exhaust leaks. I managed to get the sound captured on video, it's within the first few seconds on the video.

I had a little mishap where I downshiftted from 5th to 2nd at 100mph a few months back. I had to replace 3 bent valves and replaced all the retainers. I don't believe any of the springs nor pushrods were changed. And this popping started as soon as the car was put back together, I thought it was a tune issue but it still did it after it was tuned again. Could a slightly bent pushrod or weak spring make the occasional pop?

If this is the case of a slightly bent pushrod or weak spring would you think it should be justified that I don't pay for any labor, just parts since they didn't catch it when they put everything back together the first time?

(The pop happens in the first few seconds)

https://youtu.be/B4C8FA1WPE4

motorhead · 08-20-2015, 07:19 PM

Could be a valve not seating correctly or maybe a cam lobe. Is the pop through the intake or the exhaust?

damian559 · 08-20-2015, 07:23 PM

It's through the exhaust

two_wheel_mayhem · 08-20-2015, 07:30 PM

Doing a little racing in "Mexico"?????

Sounds like a valve fails to open. If it's a sharp hiss like the sound when you uncouple an air hose. If I was right there I would really recognize the noise. My sound on my pc sucks and I'd hate to send you in the wrong direction but...... you think it's a valve not opening correctly, I think it is a valve not opening correctly, and the engine has done it before.

When you break a rocker or bend a pushrod, stuck valve etc. they make that noise all the time at idle.

Start at the top, and work your way down.

motorhead · 08-20-2015, 07:56 PM

Sorry couldn't open the video before my first post. Did you check the plugs. I highly doubt that it is a cam lobe with it coming out the exhaust instead of intake and also the randomness of it. Do you have any codes? That mustang beat you so it obviously isn't running right either.

sorry just a joke.

TopDawg_43 · 02-25-2024, 12:33 PM

Just had this happen with my car. Was a loose coil pack that caused it.

Moto-Mojo · 02-25-2024, 12:39 PM

Quote:

Originally Posted by TopDawg_43

Just had this happen with my car. Was a loose coil pack that caused it.

What was "loose" the wire or something else?

08-20-2015, 07:13 PM	#1
damian559 Drives: 2015 1SS, 1LE, Recaro, NPP Join Date: Apr 2014 Location: Fresno, CA Posts: 927	Loud pop at idle I already asked this question and nobody on here knew so figured I'd ask again to see if anyone can help me out. My car will sometimes make a loud pop at idle almost sounds like a backfire. It happens so randomly and infrequently that my shop has no idea what it is either. It only happens every 2 or 3 times I take it out. The car doesn't feel weird and it still dynos the same numbers it did before. I recently put the car on a lift and checked the headers and mid pipes for any exhaust leaks. I managed to get the sound captured on video, it's within the first few seconds on the video. I had a little mishap where I downshiftted from 5th to 2nd at 100mph a few months back. I had to replace 3 bent valves and replaced all the retainers. I don't believe any of the springs nor pushrods were changed. And this popping started as soon as the car was put back together, I thought it was a tune issue but it still did it after it was tuned again. Could a slightly bent pushrod or weak spring make the occasional pop? If this is the case of a slightly bent pushrod or weak spring would you think it should be justified that I don't pay for any labor, just parts since they didn't catch it when they put everything back together the first time? (The pop happens in the first few seconds) https://youtu.be/B4C8FA1WPE4 __________________ 2015 Summit White 1SS, 1LE, Recaros, NPP 498 RWHP 447 RWTQ (Motor) 647 RWHP 723 RWTQ (150 Shot) 12.1 @ 117 (Motor) 11.7 @ 129 (Nitrous) Nitrous Outlet Single Nozzle Kit \| Stand Alone Fuel Cell w/ C16 \| Custom Grind Cam \| Stainless Power 1 7/8 LT Headers \| CAI Intake \| ATI Super Damper \| BMR Trailing Arms & Toe Links \| Prothane Polyurethane Sub-frame Bushings \| JDP Upper Control Arm Bushings \| MT Drag Radials \| Tuned by SS Motorsports Youtube Channel: Click Here

08-20-2015, 07:23 PM	#3
damian559 Drives: 2015 1SS, 1LE, Recaro, NPP Join Date: Apr 2014 Location: Fresno, CA Posts: 927	It's through the exhaust __________________ 2015 Summit White 1SS, 1LE, Recaros, NPP 498 RWHP 447 RWTQ (Motor) 647 RWHP 723 RWTQ (150 Shot) 12.1 @ 117 (Motor) 11.7 @ 129 (Nitrous) Nitrous Outlet Single Nozzle Kit \| Stand Alone Fuel Cell w/ C16 \| Custom Grind Cam \| Stainless Power 1 7/8 LT Headers \| CAI Intake \| ATI Super Damper \| BMR Trailing Arms & Toe Links \| Prothane Polyurethane Sub-frame Bushings \| JDP Upper Control Arm Bushings \| MT Drag Radials \| Tuned by SS Motorsports Youtube Channel: Click Here

08-20-2015, 07:30 PM	#4
two_wheel_mayhem Would rather be riding Drives: No car no more Join Date: Jul 2009 Location: Indiana Posts: 2,750	Doing a little racing in "Mexico"????? Sounds like a valve fails to open. If it's a sharp hiss like the sound when you uncouple an air hose. If I was right there I would really recognize the noise. My sound on my pc sucks and I'd hate to send you in the wrong direction but...... you think it's a valve not opening correctly, I think it is a valve not opening correctly, and the engine has done it before. When you break a rocker or bend a pushrod, stuck valve etc. they make that noise all the time at idle. Start at the top, and work your way down. __________________ No dog in this fight anymore. 5th Gen owner 2009-2016.

08-20-2015, 07:19 PM	#2
motorhead Drives: Love the one you're with Join Date: Sep 2009 Location: Downtown Charlie Brown Posts: 11,850	Could be a valve not seating correctly or maybe a cam lobe. Is the pop through the intake or the exhaust?

08-20-2015, 07:56 PM	#5
motorhead Drives: Love the one you're with Join Date: Sep 2009 Location: Downtown Charlie Brown Posts: 11,850	Sorry couldn't open the video before my first post. Did you check the plugs. I highly doubt that it is a cam lobe with it coming out the exhaust instead of intake and also the randomness of it. Do you have any codes? That mustang beat you so it obviously isn't running right either. sorry just a joke.

02-25-2024, 12:33 PM	#6
TopDawg_43 Drives: 2014 Camaro ZL1 Join Date: Dec 2019 Location: North Carolina Posts: 28 View My Garage	Just had this happen with my car. Was a loose coil pack that caused it.