I have read the link posted on here that recommends towing at 1000 miles to help break in your engine. I am meticulous with all of my vehicles so that being the case this one is no different. However this being my first diesel i blindly followed this instruction without really knowing why. I mean I read the article and i get the gist of what the author is saying. I guess i just find it hard to believe that every diesel owner has read this article or something providing similar instructions.

Say for example someone who has never read this information goes in and purchases a LMM or any diesel 3/4 ton for that matter fresh off the lot. They baby it like a new car through all of the gears and don't get the RPM's very high and consistently drive this way in town. While on the highway they conservatively get it up to speed and set the cruise at 65MPH and wallow in the slow lane. They continue to drive this way for the next 15k miles... Basically like every Prius driver.

My question is what effect would this kind of driving have on the engine as opposed to following the break in regimen which i read on here all the time?

I dont buy any of it. i have 8000miles on mine right now and didnt follow any of it and get 15 to 16 mpg street and 20 to 22 highway, no problems. keep an eye out for squeaky windows though, i just took mine in and they are starting a field report over it. they have no idea why they do it and it has left a big scrtch down my driverside window. but i think youll be fine drving them the way you want from the beginning!!

by the way didnt drive it like a prius, drove it like a ferari

I don't buy it either. What are the author's credentials, and what data can be provided to back up his claims? I'm guessing 99% of diesel owners don't follow that procedure. I know I won't.

I dont buy any of it. i have 8000miles on mine right now and didnt follow any of it and get 15 to 16 mpg street and 20 to 22 highway, no problems. keep an eye out for squeaky windows though, i just took mine in and they are starting a field report over it. they have no idea why they do it and it has left a big scrtch down my driverside window. but i think youll be fine drving them the way you want from the beginning!!

x2 on the windows. I took mine off the lot with the passenger side window
squeaking. I took it back to the dealer, fixed it in 2 hours, not a problem since.

I didn't pull anything until about 4,000 - 5,000 miles. 8,000# travel trailer with a few hills included. It is too early to tell, but so far so good.

[quote=jpat209;2541160]They continue to drive this way for the next 15k miles... Basically like every Prius driver. Myquote]

Seems like all these Prius drivers up nort' here are driving them like they stole em and complaining they don't get the mileage they expected...sorta like some of us on the site here;).

I bought mine and the next day I was pulling a trailer with it at 200 miles, its b.s. if you ask me.

[quote=jpat209;2541160]They continue to drive this way for the next 15k miles... Basically like every Prius driver. Myquote]

Seems like all these Prius drivers up nort' here are driving them like they stole em and complaining they don't get the mileage they expected...sorta like some of us on the site here;).


thought about that the other day, they should limit them to 55 or 60mph....see how many buy them then...

Have 6000 miles now, was running 400rwhp at 500 miles, and 500rw at 1000 and been romping it ever since. No probs

But what about the Owners Manual stating you should keep break-in towing speeds under 50!!! mph for the first 500 miles. I'm afaid someone on the highway would try to shoot me if I did that towing my race car trailer. Man, under 50 and it doesn't matter if you already have 3-5000 on the clock. It is the "towing" brake in the book specifies.

Steve

First thing to do is to check ALL fluids. My rear was 1 qt low, TC 1/2 qt ,front 1/2 qt, and tranny was 1 qt.
I didn't do the 50mph thing. At around 1000 miles I changed the engine oil and I towed my 14500# (dry) TH up and down a local 4 lane, maybe 100 miles. I kept in in manual shift mode and switched from 5th to 4th to 5th for 2-3 min intervals. Running around 55 to 60. I didn't let it go to 6th and I don't think it would have. The following week I made a 600 mile RT, with TH around 15500#, mostly interstate. 65mph going and 70-75 coming home. No troubles. 2500 miles on her now and about to dump the other fluids in prep for 2000 mile RT to the Carolinas. So far so good.
Just added an aux 50 gal tank/toolbox today from ATTA. Won't have to stop every 3 hrs for fuel. (7.5 mpg towing.)
Good luck, you won't need it! She'll be fine. :D

i have a lbz which is about the same and at 30ish miles I installed mods in sig and i was already hauling 13k. I have 18k now with no problems or tranny limps and get 20mpg empty. BTW I haul with my pred on kill

x2 on the windows. I took mine off the lot with the passenger side window
squeaking. I took it back to the dealer, fixed it in 2 hours, not a problem since.

I didn't pull anything until about 4,000 - 5,000 miles. 8,000# travel trailer with a few hills included. It is too early to tell, but so far so good.
what did they say they fixed, they cant figure out what the problem is on mine, their gonna try new motors and other stuff!!

Last august, with 500 mi on the odo, I made a 2000 mile trip pulling 9000# trailer. 65 mph most of the time. Never had a problem then or since. Never overheated in spite of 100* ambient temp. My fuel mileage since has been on the high-side of average (14-15 city, 18-21 highway un-loaded). The thing to remember is the same basic Duramax engine in your Silverado/Sierra is also used in Medium duty 4500 and 5500 series commercial trucks, dump trucks, etc. and you can be sure they are run max load from day one. So stop worrying, and drive.
:driver:

Glad to hear you guys aren't having any problems; I am not either. My question was is there any proven benefit of breaking in a diesel engine as opposed to just buying it and ignoring the break in recommendations?

It's not so much that the diesel needs any special type of break-in than a gasser. I think all engines need a breakin period. What you are trying to accomplish during break-in is ring seal. (piston ring to cylinder wall) no ring will really seal with out a load applied. Ring seal is what keeps the compression with out leakage for optimun performance. If a motor any motor gas or diesel is let run when new without load the rings will glaze the walls and never have a seal as good as those that been made to work. No you don't have to run the crap out off it but you do have to make it work. Load! Look at race motors, you can't drive a racecar around and if on a dyno after the first 20 minutes of running all fluids are changed and then run it up with a load. I used this method and I never had any more than a 3-6% leakage on cylinders with a leak down gauge.

I did the 1,000 mile tow just by chance before seeing that article - all I know is my MPG's are damn good.

Can't post the article (from a competing site) anymore least the moderator Nazi's slap me again. Google "How to break in a diesel engine". and it will be the first page to pop up.

http://www.google.com/search?hl=en&q=How+to+break+in+a+diesel+engine&btnG=Google+Search

Mine has the same scratch on the driver side. I took it in for a service visit, and the bracket for the power window broke and it made a noise when opening. Maybe related?

Well I bought the truck to tow with and thats what it does. Put about 300 miles on it before I put it to work. Its been dragging my TH around for about 1000 miles with no issues. Not sure if my mileage is where it should be as the best I have ever got when driving like an old lady is 18.7 but have never see anywhere close to that in real world driving. Averaging 14.5 overall. I am curious now on my fluids. I have checked the oil but thats it. I figured GM could at least put the correct amount of diff fluid and trans fluid in the thing.

I drove it the way I intended to drive it the second it left the lot with 23 miles on it. My truck hasn't been babied a day in its life. An 850hp race engine I could see a proper break in for, but not something produced for the masses. BTW- I don't use any oil in between changes and my mpg has remained the same since day one.

I read somewhere on this site before, J. Kennedy said it's more important to take it easy for 500 miles for the rear end than it is for the motor.

I believe in break in periods. Varying load conditions and no long term steady RPM's for long periods of time. I believe proper break in and proper maintained engines will still be performing well past the two to three hundred thousand mile mark. I do business with Jr. at Insulaire in Ga. The man runs several Duramax's well over the 300,000 mile mark. When he buys a new truck he drives the truck for the first 1500 miles or so. Stretches the frame flat beds them and puts them to work. Seems to work for him.

what did they say they fixed, they cant figure out what the problem is on mine, their gonna try new motors and other stuff!!


My windows squealed when going up and down from day 1. First, dealer pulled all door panels and lubed mechanisms. They said they have had trouble with them. That didn't do it. Sounded like the window tracks or wipers (for lack of a better word, along door between the tracks). They sprayed the hell out of the tracks/wipers with silicone. Took 2 days to get it off the windows but now they're quiet.

I drove it the way I intended to drive it the second it left the lot with 23 miles on it. My truck hasn't been babied a day in its life. An 850hp race engine I could see a proper break in for, but not something produced for the masses. BTW- I don't use any oil in between changes and my mpg has remained the same since day one.


MPG should be improving with a properly broken-in diesel engine, not remaining the same.......

I drove the sumbitch like I stole it from day one. Week I bought it, I changed the oil, and drove it from AZ to Cabo, Mexico. A chunk of that on the Baja 1000 course. I think the entire break in thing is left over from the 40''s, kind of a "my dad's dad told him to do it this way and he told me to do it this way and I told my son he needs to do it this way". Not unlike the ol' "gotta change the oil every <enter non-scientific mileage number as handed down through multiple generations here>".

It's all anecdotal "I've heard...........My buddy is a <enter some brand here> factory mechanic and he said...............I know an engineer at <some manufacturer> and he says...."........it's all bullshit. There is not one single scientific study that anybody can reference in any way shape or form that shows one method of break in is any better or results in any more engine longevity or fewer long term engine problems than any other.

There goes that damn echo again.

My windows squealed when going up and down from day 1. First, dealer pulled all door panels and lubed mechanisms. They said they have had trouble with them. That didn't do it. Sounded like the window tracks or wipers (for lack of a better word, along door between the tracks). They sprayed the hell out of the tracks/wipers with silicone. Took 2 days to get it off the windows but now they're quiet.

You should always take it easy on your power windows for the first 500 miles, until the motor and gears have a chance to break-in! :D

There goes that damn echo again.

Yep. Hey, maybe if you break in the 3500 real careful........the dealer will buy it back too;-)

Yep. Hey, maybe if you break in the 3500 real careful........the dealer will buy it back too;-)
You think? I heard if you spend too much time in the desert you mite get delirious and start rambling on. Now I know its true. Maybe if you had a couple a cold beers you would come to your senses.

You should always take it easy on your power windows for the first 500 miles, until the motor and gears have a chance to break-in! :D
I think your right.:D No seriously though they had to replace one of the motors to stop one of them. now the other window is faster than the one they put the motor in, maybe i just need to take it easy for 500 huh!!:rolleyes:

You think? I heard if you spend too much time in the desert you mite get delirious and start rambling on. Now I know its true. Maybe if you had a couple a cold beers you would come to your senses.

You know what, just so happens there's this guy who owes me some cold beers............

I read somewhere on this site before, J. Kennedy said it's more important to take it easy for 500 miles for the rear end than it is for the motor.


Rear end gears have super tight clearance and get hot as the surface of the sun until worn in together. Well, maybe not quite that hot, but hot enough for a tightwad company like GM to use synthetic lube. Oh, that lube still gets cooked, plan on changing it after the first 500 miles of towing.

The engines are run in at the factory before installation in a truck (I think).

jb