What's that noise? Louder chatter when cruising

[zzman]

What do you guys think this may be?

When driving on the highway or really any speed, that diesel chatter gets louder when the engine is not under strain or not slowing down. When maintaining a steady level speed, the chatter (the sound from all diesels) gets a little louder.

I just starting noticing it a couple weeks ago. No loss in power, no extra smoke, no missing or anything I can tell. At first I thought it was the transmission but it does it in every gear and any speed.

Now I think it may be an engine issue. I don't know what happens when injectors go bad, or if the valves need adjusting.

I just found a water leak and I think it is the water pump. I don't think that would make the noise. Only added about 1/2 gal of water if that much.



The noise is the same noise all diesels make, it just gets a little louder when cruising, any ideas? am I in danger here????

What do you guys think?

Thanks

 

[Mark31]

My ride (85k) is doing the same thing: It sounds like a gas engine that needs higher octane gas. Dealer's 35+ year experience mechanic says lets do a valve adjustment and see if it has any effect. I am starting to believe I have an injector acting up, though. One day there was no noise, then next day it was back again. Let us know what you find. Mark PS I took the Roktec off when this started, but no difference.

 

[rbattelle]

When driving on the highway or really any speed, that diesel chatter gets louder when the engine is not under strain or not slowing down. When maintaining a steady level speed, the chatter (the sound from all diesels) gets a little louder.

My truck has been this way since the day I picked it up and drove it home, March 2003. 81k miles later, everything is fine.



I have found that a cetane booster quiets it down a bit, but doesn't eliminate it.



Here's what I think is going on. I think these engines are so quiet that many of the noises that diesel engines normally make seem amplified.



It's been this way since the dawn of the common rail engines. Chatter about noises like this has decreased over time, as people become more accustomed to the new "right sound".



I believe the noise you're hearing is directly related to fuel quality and will not harm the engine in any way. You might try a cetane booster, or try refueling at a different station. Also, in my opinion these engines make more noise when it's cold out, so if you're driving in cold weather you're likely to notice more.



Ryan

 

[bzingre]

Similar Issue

I notice when its very cold, I get a loug clatter when engine load is reduced while cruising. Sounds like timing goes full advance... I have no idea why it does it? This 03 also acts like it "runs out" of fuel after cruising around 84 mph. If I lift my foot off the throttle slightly, it's like I shut the key off. Then after 4-5 seconds it's like the fuel slams back on and it jerks the drivetrain. After the 3 or 4 concecutive occurance, check engine light comes on but no derate. Issues occured before and after FASS install...

 

[Mark31]

I took my in warranty 04 Cummins (85K) to the stealership today to have the valves adjusted because of the "spark knock" sound. The tech drove my truck a few days ago, couldn't hear the noise I hear, but said a valve adjustment was a good starting place. He said a 6 hour cool-down to get a good adjustment. However, today it only had a 3hr (at most) cool-down and then was started instead of pushed inside. Today, he said as long as it was under 140 degrees it was ok. He said that I had 2 very tight exhaust valves. I don't know whether it was 2 or 2 pair that were tight. They were adjusted by Addy Dodge in Lexington, SC 30k ago (I wasn't happy with that whole scenario) and today by Mike Addy Dodge (who bought out Addy Dodge). I don't think it took him much, if any, over an hour. The bill was $240, all flat rate labor @ $120 (I think) an hour. I'm not a happy camper. I hope I don't ever have to set foot in a dealership again. I don't hear the noise now, but I'm still going to get a local independent to go back over them. I had a tweeked old sohc Honda 750 that pulled hard past 10500 rpm (stock redline was 8000) that I fussed over the valve adjustments until they were exactly exactly and every one sounded alike. The tech knew this and that I wanted his best job, not in tolerance, but exactly exactly. I feel like somebody has poured clabbored milk on my Cherrios. Am I wrong and expecting too much or do I have a legit beef? End of rant, but I still don't feel any better!! Mark

 

[zzman]

I decided to adjust my valves last weekend, I remember doing them at 80k miles but not since then. I think 1 was good and 1 was too tight and the rest all too loose. I believe the sound has gone away or atleast quieted down where I can't tell. And the bonus was I believe I'm getting better milage.

 

[SShafranko]

Valve adj. should run you between $80 and $140. No more than that.

 

[Slow Six]

I have that same noise in my 03 as well. Something I just noticed some time ago. Every thing is working okay, mileage, power etc. is all the same. The light rattle is more noticeable after engine is warmed up. This is an interesting thread which I will follow to see the results.

 

[TCDiesel]

A poor working FCA at times will cause this (Rattle).

 

[Slow Six]

Twest, I hope you are right as I am waiting for one to arrive from Geno's.