Sounds Different?

[LCink]

Got 04 cummins and now when it goes to fast idle i can hear a popping sound coming from exhaust any ideas on what to look for?

 

[steved]

Mine did that right before my injector failed... sorta had a bump in the idle.



When it got really bad, it actually loped in high idle...

 

[LakeLife79]

Most likely a bad injector or two. Other than that you could have dropped a valve and it is slapping the piston.

 

[steved]

Most likely a bad injector or two. Other than that you could have dropped a valve and it is slapping the piston.

Valve seat?



I would assume if it was an interference issue, it would be more pronounced at all speeds??

 

[LakeLife79]

Yes I would assume that too but as the RPMs go up so does the noise of the engine itself. The normal engine and exhaust noise are cancelling out the pooping sound. I have had injectors go out twice on my 06 and neither time did i hear anything funny in the exhaust and I did listen to it.

 

[steved]

Mine definitely had a bump in the exhaust before I lost an injector... it loped in fast idle right before it failed.