Breaking Engine In Without A Trailer

[Boosted Inline Six]

I've read what I can find on breaking in the engine. Most say to run it hard with a trailer. I don't have one yet. We're getting one but not for a couple months. Would it be dumb or damaging to run up some steep grades with the transmission in 2nd gear to get the revs and heat up? It's a 48RE. Is this hard on the transmission? I'm assuming there would be no problem with the engine?



Thanks

Bret

 

[AndyMan]

Hey Bret, and welcome to the TDR.



I don't know if that would help or not. There are several schools of thought on break-in. From what I've pieced together, keep is gentle for the first 500-750 miles, then pour it to it. Do a search on "break in". That should keep you reading for a while.



I'm not sure if short uphill runs like that would do you much good. But then again, what do I know... I used a sled to break mine in.

 

[rbattelle]

I don't think it would be worth it. I mean, you'd have to drive 5000 miles up that hill in order to have any real beneficial effect.



I don't tow anything (never have). My break in strategy was to vary my speed on the highway for the first 500 miles (I varied continuously between 55 and 70. . bad for traffic, good for me). After that, I avoided full-throttle starts and generally tried to expose the engine to a range of RPM and throttle positions for the next 15000 miles. Once I hit 15k or so, I just drove normally.



I'm a pretty conservative driver, most of the time. Every now and then I open it up to clean out the soot that's collected in the exhaust.



-Ryan

 

[Pawpaw]

My '04 has a bit over 39,000 miles now. I pulled a trailer exactly once. It was a U-Haul car trailer. Did 40 miles loaded and 40 unloaded. Other than that, I just drive it.

Don't sweat the break-in. Just watch your fuel mileage slowly increase as it happens.

Bob

 

[BHolm]

I think the idea behind pulling some wieght to speed break-in is to produce cylinder pressure and help better seat the rings. If you run it up a hill at 2800 rpms in second with no load, you are not working the engine much.



What I might do is load the bed with as much wieght (within reason ) put the trans in D, engage the tow/haul, and then pull some grades with it. Try and let the convertor lock, which it will do in T/H, and then pour on the throttle letting the boost build at a lower rpm, say starting at 1500 or so.



Really though, you don't need to do anything. Two months from now when you have to pull the trailer I bet you wouldn't be able to tell if your break-in trick worked or not. It will pull like a train either way. I certainly can't fault you for looking for an excuse to work the truck though :-laf Enjoy

 

[rbattelle]

I think the idea behind pulling some wieght to speed break-in is to produce cylinder pressure and help better seat the rings. If you run it up a hill at 2800 rpms in second with no load, you are not working the engine much.



What I might do is load the bed with as much wieght (within reason ) put the trans in D, engage the tow/haul, and then pull some grades with it. Try and let the convertor lock, which it will do in T/H, and then pour on the throttle letting the boost build at a lower rpm, say starting at 1500 or so.



Really though, you don't need to do anything. Two months from now when you have to pull the trailer I bet you wouldn't be able to tell if your break-in trick worked or not. It will pull like a train either way. I certainly can't fault you for looking for an excuse to work the truck though :-laf Enjoy

This is a good post. I would add that Cummins specifically recommends against going to WOT when the engine is below the peak torque RPM (which I believe is 1600 on 2004. 5-up trucks).



-Ryan

 

[BHolm]

Ryan is right, the nice thing about the auto is that it will jump the rpms if you lug it. My experience with the T/H and grades is that you can build decent boost, which is the goal, without lugging.

 

[HParfitt]

Agree 100% with BHolm.

It's amazing how even towing a light trailer 5000# - 7000# builds temps and boost levels. Getting a set of gauges really teaches you a lot about how a diesel works. You can see how lugging really pushes up egt's first hand. You can also really watch egt's and see how mpg's go up and down. For that alone I think gauges are worth it. I think putting a big load in the if you don't tow a trailer might be better than running big rpm's. I noticed my mpg's climbed after my first 1000 mile tow.

 

[JVolpe]

What is wrong with weight in the bed. Enough 80-100 bags of sand will definitely put a load on everything.

 

[rbattelle]

What is wrong with weight in the bed. Enough 80-100 bags of sand will definitely put a load on everything.

Nothing at all! I've heard of people doing that. Smooths out the ride, too.



Of course, when you're done you've got to find somewhere to get rid of all that sand.



-Ryan

 

[JVolpe]

Sand went in the holes the new puppy dug in the back yard. Puppy thought to be a 25lb mutt is now 50lbs at 6 months.

 

[nickleinonen]

just get a few hundred miles of city type driving in to break in the gears and trans, then beat the crap out of the engine by basically racing it as hard as you can... 100% throttle off the line all the way to your speed limit and just plain drive it hard... that is the best way to break an engine in [best way is on an engine dyno at full load for 20-30min on larger 10-15 liter engines, and like 75% load on smaller ones]