2014 LML Engine Noise

[Camaross22]

I recently purchased a 2014 Rocky Ridge Silverado 2500 LTZ Z71 and I love it. I noticed once I picked it up the miles were a little higher then promised, (the truck had to be delivered from another portion of Florida), and the engine oil life was 51% with the truck only having 550 miles on it. That scared me and I demanded that the oil be changed, and before the oil change there was no issues, minus the tires being out of balance and the alignment off. The dealer gladly changed it for me free of charge, and once I picked it up, I noticed there was a very loud "tin" ticking noise coming from the engine. I know on these trucks there is a TSB for noise coming from the drivers side fender well, but this was not normal, Ive blown up plenty of LS chevy engines. ;). I told them something was wrong and their tech denied it up and down, so I said screw it and took it to another dealership, where the heard the noise but did not know what it was, so they told me to put some more miles on it. The noise faded away and I assumed it was just something weird during the break in period. I now have 6k on it and just had the second oil change done and the noise is back with a fury and even louder. Its not a constant noise, and almost sounds like rod knock, but it isn't constant. I'm guessing either, a bad injector, collapsed lifter, or bent pushrod. When the engine is fired up cold it sounds perfect, but once it gets to about 140-150 the noise starts and seems to correlate to oil pressure, eg. once the rpm is above 1200 the majority of it goes away. If anyone has any insight please let me know.

[GM Customer Service]

Hello Camaross22!

We are sorry to hear of the concerns you are experiencing with your 2014 Chevrolet Silverado. I understand you are seeking advice from your fellow forum members, however, we'd be happy to look further into this. Although we may not be able to provide any technical information, we'd be happy to be a liaison between you and your dealership. If you'd like our assistance, please send us a private message with your contact info and VIN. We hope to hear from you soon.

Sincerely,

Andraya R.
GM Customer Care

[More Power]

You didn't mention whether or not this was your first diesel vehicle.

As quiet as the Duramax is, there will be normal/typical noises that an owner, who only has gas engine experience, might be concerned about. Changes in load, rpm, boost pressure, DPF regen, engine temperature, ambient temperature and fuel quality can all affect how the engine sounds.

If there was a mechanical problem with the valve train, it would likely degrade to a point of failure long before reaching another 6000 miles.

The noise, which appears to be linked to an oil change, sounds a lot like what the first generation LB7 Duramax owners reported. In those, the problem was a bit disconcerting, but it had no affect on engine durability or longevity. My opinion is that new oil will "gas off", creating bubbles in the oil as it passes through the crankshaft bearings, which then pop under pressure. Somewhere before 500 miles after an oil change, the sound goes away.

Owner alarm over the sound won out, so the engineers at DMAX and GM Powertrain reduced the engine's oil pressure in later generations of the Duramax 6600, which seemed to help with the odd noise. Me personally, I'd would rather have the higher oil pressure (as it was designed) and know that the sound is nothing to be concerned about.

Jim