GM 6.5TD sound diagnosis

[Matt Hixson]

Sorry if this is off topic a bit, but just wondering if anyone might have an idea what my 6.5TD did yesterday on my way home from work. I happened to have my GoPro recording.

The GoPro is in the waterproof case mounted to the brushguard. You can hear it in the video below at 0:18, then a very short noise at 1:05, and then again at a much lower speed at 2:15. Each time this happened there was no loss in power or any kind of drivetrain feel to it. Sounds to me like it is from the engine.


Any thoughts what this could be?
Thanks for any help,
-Matt

 

[Tim N Michele Davis]

My best guess is the pump advanced timing for a sec or 2. Did it set any codes?

 

[Road]

Exactly - do you have an OBDII reader? Throwing any codes?

I ran a 6.5 TD Duramax for about 8 yrs, and my current 6.6 TD Duramax for about 6 years, and wonder if it is when it is shifting, either up or down. Sounds like a slight grinding not just knocking, and that it is intermittent tells me it might be gears meshing? I'm no mechanic, but that's my first impression. I could be way the hell off.

Here's a post on transmission or transfer case noise on the dieselpage forums: http://www.thedieselpageforums.com/tdpforum/showthread.php?t=30753

Here's a youtube vid on front diff clicking:

Here's a whole page of 6.5 TD slight grinding noise results that may shed some light on the problem. One guy there had a noise and spent a ton of money and new drive shaft etc only to find out it was part of the emergency brake that had come loose in the wheel.

Not saying any of this is what yours is doing, but that it is often quite misleading.

Good luck - let us know what it ends up being.

 

[Matt Hixson]

My best guess is the pump advanced timing for a sec or 2. Did it set any codes?

No codes were thrown.