I finally got a travel trailer to put behind my bone stock 2006. I took it to west Texas this past weekend and everything went pretty well. (Other than I wish I had my old NV5600 rather than the 48RE, but that's another issue! :-)) There was one thing that I did notice, though. At heavy throttle settings, especially under 2200 RPM, there is a persistent rattle sound. It sounds similar to the detonation sound you get from a gasser that doesn't have enough octane. I might imagine that I didn't have as much power as I might have expected, though by no means was the truck struggling. Using the ignition key codes checking sequence indicates that there are no codes, so everything appears "normal".

This truck is mostly a daily driver with many short trips. It only has 47,000 miles on it right now. I put over 500 miles on the round trip and found that the rattle was present at the beginning and end of the trip. For quite some time I have been feeling like my unloaded fuel economy is lower than it should be, getting something resembling 11 to 13 around town (most trips < 4 miles), and usually 17 or 18 on the highway. My only comparison is my 2002 2wd with NV5600 which got 16-18 and 20-22 under the same conditions.

The trailer weighs around 5,500.

Any thoughts, or is this just the life of a 2006? Programmer time?

Thanks,
Tad

Any thoughts?

 

It is possible that the injectors are carboned up from the short trips.

Did you do much full throttle while towing to get the EGT up for a while to burn the carbon away? Towing only 5,500 lbs. is not much of a load unless you had some long hills to climb. Some injector cleaner might help.

 

I thought about that even before I left and I drove it like fuel was cheap both ways. Especially heading out on Friday. West out of DFW is predominately uphill, lots of long climbs (hills, not mountains) and I was into the wind the whole way. I put my foot on the floor for every climb.

I've also used Power Service Diesel Kleen fairly consistently for the past several years.

 

Bump?

 

I noticed the same noise you are describing, the first time I towed our T.T.(also approx. 5500#s) up a hill. What it may be, is loose injector line isolators (they are blue). Check them and tighten them up. I recently did it on my 07 5.9 and it sounds like a new truck. I also put Loctite on the threads. It's amazing how much noise is generated from them being loose.

 

re: Unloaded mpg

Unfortunately due to our location, with construction and hellish traffic, I think the unloaded runnin' 'round town mpg will stay relatively low if you drive to keep up with traffic's acceleration from stops. I'm getting between 14-16 city (I'm in Grapevine). I've learned that I'll live with tickin' people off who drive behind me. I accelerate from stops trying to stay under 1700rpm; usually 1600 on the nose is my snail's pace. I can time the lights properly when traffic is light, but those light traffic periods of the day are few and far between with all these commuters clogging up my roads

I am using a Quadzilla Mileage Max with the City_tune in an attempt to keep the city mpg at a tolerable level. (It targets <1700RPM). My highway mpg I'm satisfied with. But unless I run out of town the truck doesn't get to stretch it legs at a consistent pace. Everywhere around DFW, including the freeways is always stop and go, or at least not steady cruise.



As for the injector rattle, my husband noticed it the other night riding in the truck. It's more noticeable with the radio turned down

For a while I ran TCW3 about .5oz/gal. It slightly quieted the injectors but seemed like it muffled mpg a hair. I stopped using it when I put on the the Quad mileage box so I could see what the box did by itself. I have not gone back to TCW3 yet. Maybe this summer as it will have given the Quad mileage box a full year of data by itself.

 

Here is a similar discussion on the clatter ... could be normal.

https://www.dieseltruckresource.com/...r-t295034.html

 

Just a thought, but have you thought about checking your valve lash? Still a relatively new truck but that doesen't always have to mean that something like valve lash can't be out of whack. I'm assuming you still have good power but checking the lash is pretty easy insurance.

 

Good call.

This is in the back of mind when I think about the injector rattle. I have read of low mileage trucks needing a little adjustment. I think the manual calls for valve adjustment at 100k. But that certainly doesn't mean it might not need it earlier.

I need to learn how to do this. I've never seen it done or been taught so I don't know where to start. I guess I could read it on the internet

 

I found this video on the subject of valve lash adjustment:

http://www.youtube.com/watch?v=GLi03bG4zAw