Is it considered "normal" during a regen that the engine seems to have more of a "diesel clatter" ? I noticed it today when I had the window down, seemed to return to normal sounds as soon the regen had completed. This is an 08, completely stock. Haven't had it long, and just trying to get used to all this regen bs. Getting ready for a trip pulling our 38' 5'er, and trying to avoid any unnecessary surprises. The difference in mileage from my Duramax has been enough of a surprise, and it unfortunately wasn't a good surprise. Have been enjoying the truck otherwise.

 

Yes sometimes I notice a slight difference in sound. It is that post injection for the regen process that makes it.

Normal.

You'll like the truck more after you tow with it. Have you gone out on a couple of test runs with the 5er?

 

Agreed, you will hear a little more clatter on regen. I use about 8 oz of Diesel Kleen every other tank. It seems to quiet it down significantly and also cleans the injectors a bit.
I believe you will like pulling with this machine. I just did my first pull with my 5er with my 08 to Colorado. It was really a nice easy pull and drove like a dream.

 

Thanks for the reassurance. Have not had the opportunity to pull the 5er with it yet. I did pull a LARGE boat to the Ozarks for a friend recently. Other than the mileage, no problems. It weighed a little over 16,000 on the trailer, so almost as much as our 5er.
The mileage only comes as a disappointment after a couple of Duramax's that did so much better. But, they were pre- kill everything with EPA regs. I think the newer ones probably don't do much better than I get with the SD.
I like the truck itself much better. Seems to really not have any power until it gets to 2000 rpm, (turbo lagging), then it really starts to pull. The Duramax seemed to be the exact opposite, everything on the low end, nothing on top. Just an adjustment that I'm sure I'll get used to over time.
Thanks again for the help. Love this forum!

 

I can almost feel when the truck is about to regen just from the sounds of it. There's the 'usual' diesel clatter but after a regen, it feels like the motor spins more easily and seems a bit quieter than usual. It starts getting a bit louder and raspy slowly over in the last 50miles or so; then wham, regen starts and the engine gets real raspy.

I don't get a 'cleaning exhaust' message for more than 1-2 seconds so I normally miss it, but I know for sure it's in regen when it does it.

I've also started using DK every tank. Haven't noticed if it makes things quieter, but I do seem to notice a 0.5~0.8mpg hand-calculated increase. My mpg meter sees it and it started climbing up from 13.4mpg to 13.7mpg range on the 2 first tanks though my driving hasn't really changed much.

I've been getting fuel from a truck stop if that makes any difference.

I just got back from an 800mile near-all freeway trip between San Jose and LA lightly loaded with 4 of us and a few hundred lbs of stuff in the back. I was easy on the pedal with cruise control 65~70mph most of the way. Wife was complaining I was driving too slow :-( Drove through the Grapevine on I5 and then a stretch coming back on 101 where boost was up between 25-28psi uphill. 2 tanks of fuel checked in with 15.9 and 16.4mpg and included 3 regens--1st and 2nd were on the first tank (probably explains why mpgs are lower than the 2nd tank); the 2nd and 3rd regen occurred shortly after going over the mountain passes.

 

Sorry, disregard.

 

The turbo on mine used to make a weird almost like a squeal sound when it was in regen. Also the boost seemed to fluctuate a lot when in regen. Glad i dont have to deal with that anymore.