Popping noise on cold starts, dealer found NEW ONES on the lot with the same problem - no fix.

[Bad Mojo]

A little background... I developed a popping noise from the air box on cold starts on my '19 Rubicon, it only lasts until it gets gas and it goes away. It will not return until the vehicle has sat until it is completely cold again. On my initial visit the dealership worked with FCA and determined that an ECU update might fix it. They did the update, started the Jeep, no popping (because it hadn't cooled yet), and gave it back to me. The next morning it was popping.

I took it back in last week. They reached out to FCA/STARS (he mentions both, I don't know what the difference is), who had no idea what it could be. Their initial thought was bad or old gas, that proved to not be an issue (I only fill up with 91, which is the highest available in CO, and all my vehicles get filled up at the same place with no issue). They went back to the drawing board with FCA/STARS.

At some point, either the dealership or FCA/STARS thought to go start up some of the Wranglers on the lot. Per my service guy, they found several that exhibited the EXACT SAME popping sound coming through the airbox.

At this point, they have no idea what is causing it, but FCA/STARS has assured them that it's not anything that can damage the engine. So I've been told I can come and pick my Rubicon up, and when they determine a fix they will call me in to likely get another ECU update.

Sponsored

 

[AnnDee4444]

2.0?

https://www.jlwranglerforums.com/forum/threads/rough-idle-a-start-up-all-of-a-sudden.50066/

https://www.jlwranglerforums.com/forum/threads/2-0-backfiring.47286/

 

[D60]

Yeah I was recently dealing with an '05 Escape that would make a popping noise from airbox due to misfire. You could also hear a puff or irregularity at the tailpipe when it would happen.

I don't know if Mode 6 works on the JL's -- it should but I've never tried -- but I'd plug in a scanner and look for misfires (not all misfires will set a CEL). They were definitely recorded in my Escape example and Mode 6 gives you each individual cylinder -- in my example I knew it was Cyl #2

 

[D60]

Confirmed, even my $14 Launch (Amazon promo, they're $24 now) seems to work for misfire data. It knew I had only 6 cylinders so it's communicating w JL

It's under OnBoardMonitoring and you call up each cyl individually. If you get anything in the "Value" column you're getting some misfires on that cylinder. If you're plugged in during the popping noise you should see the value climb, but I think you need to exit and re-enter as it doesn't update the Value in real-time

Sponsored