Our 04 SXT with 57,000 miles makes a diesel like knocking sound just after startup and during idle. It seems to be coming from the rear of the engine and it goes away while driving or when the rpm is raised above idle. It subsides somewhat after the engine is warm but it can still be heard.
Does anyone have an idea as to what might be causing the noise.

 

My wife's 02 ES made the same noise when the weather was 40 degrees or below. I was told by some that it was piston slap and that it is also "normal". Well the noise I was hearing was not normal in my opinion. It sounded like a rod hammering LOUDLY for about 30-45 seconds after a cold start. Long story short I switched to 5w20 and a MOPAR filter and the loud knock noise went away COMPLETELY. There is still some engine noise but I think these 2.0 engines are built pretty loose from the factory. I will switch back to 10w30 next oil change now that the weather is warming up.

 

Same here, went to 5w-20 and the knock went away. and if you have cold temperatures use 0w-20.

cheers
kayakman

 

Thanks guys-I changed the oil this afternoon (5W30 semi synthetic that meets the Chrysler spec) and the noise is gone.

 

My 03 SE makes the same noise and start-up then it goes away once it warms up, sounds like it's dieseling kind of. I never thought of switching oil though, good call guys.

 

I run 5/20 Mobil 1 in our '05, has 80,000+ on the clock and not one clicking.

You should hear Chevy's! Piston slap bad, our Yukon had it bad until I ran 5/30 Mobil 1 and it doesn't do it and it has 149,000+ on the clock and recently blew the tranny