I notice the 6.5 is much quieter then the 6.2. Is it the rockers? Ip? Intake?
I notice the 6.5 is much quieter then the 6.2. Is it the rockers? Ip? Intake?
Normally the 6.5 with the electronic IP have a much harsher rattle.
They run a higher POP on the injectors.
The NA 6.2 SHOULD ACTUALLY BE A BIT QUIETER.
Now if the cold case advance is not shutting off they will rattle really hard.
(1) 1995 Suburban 2500 4x4
(1) 1997 Astro
(1) 2005 Suburban (Papa Smurf)
THIS IS BOW TIE COUNTRY
Age. And a turbo. New 6.2 trucks were fairly quiet. Today, 6.2 trucks rarely have the original intake plumbing intact. The 6.5TD has a turbo, so it needed less attention in this department. A turbo is a noise reducer, in both directions. Many states don't require an additional muffler (as a means of noise control) if it has a turbo. The N/A 6.5 is every bit as noisy as the N/A 6.2, all else being equal.
Noise, as in "combustion rattle", is largely a function of injection timing. Over time, the 6.2/6.5 timing chain will stretch to a point that it loses a degree or more in timing advance. The result is less rattle. This is/was one of the arguments in favor of the aftermarket timing gear sets.
Contact Me
Lil Red - Duramax 6600 Conversion
Content Web Site
The Diesel Page - 6.2L/6.5L Diesel Books
The 6.2L/6.5L Troubleshooting & Repair Guide
Duramax Diesel Conversion Guide
Duramax Diesel Service Guide - How to Replace Head Gaskets, Injectors, Water pump, and more - New!
Photo Album
TDP Youtube Channel - New!
Ok thanks for that knowledge! The 6.5 I have is much quieter then any 6.2 I have heard.