When is the engine really broken in?

[CTD 600]

I keep on seeing alot of advertisers saying that their used truck has 100,000 miles on it and they say that the Cummins engine is just broke in. I think that's crap. My truck manual says 20,000 miles at the most and then the engine is broke in. Where did this whole 100,000 mile just broke in thing come from? The first generations?

 

[klenger]

I'm on my 3rd CTD, but I have never kept one past 35K. That being said, they all seemed to run better the longer I had them, so I have no idea at what point I would say that it is "broken in". I think another reason for the comment at 100k is that the life expextendency for a CTD is somewhere areound 400K, so at 100K, it's "just getting broken in" is a figure of speech.

 

[macdaddy]

CTD

The complete break in will vary from truck to truck. Example how much the truck is used for towing, driven solo etc.

One way to monitor break in is the oil consumption,my 99 went 80K before the oil consumption stopped , indicating break in.

The amount of oil that the crankcase vent line is spewing is another indicator, my 99 seemed to stay the same the whole 80K though.

My 05 has 10. 5K and it looks as though it is about par when compared to the 99's break in.



Mac

 

[Cummnzpowr]

break in

MacDaddy: Do you mean the newer your truck was, it burned oil... then after 80k miles it stopped ? It should be the other way around shouldn't it?

I noticed now this 94' i got, it's using maybe 1/4 quart of oil in 7,000 miles. I am really working it though, put 20k miles on her in 3 months towing trailer alot with average load. I notice it get's better mileage now empty,and runs "looser" and smoother as i near 100k miles {about 94,000 miles now}. . so maybe the 100k mark is pretty acurate for break in. I can gaurantee 20k is BS. .

 

[Vaughn MacKenzie]

Judging by the hone marks still to the tops of my cylinders and not a hint of a ridge at 352,000 miles tells me break-it at 100,000 miles is just about right



Vaughn

 

[macdaddy]

CP

It wasn't allot of consumption 1/16th to 1/8th in drop on the dipper 1/2,to 1qt between oil changes 4 to 5K. Seemed to stop at around 80K. It(the 99) never seemed to use any ever again. I sent it on it's way before I saw green (coolant). Can you say 53????????



Mac

 

[jtwcummins]

The first weekend I had my 97 I wanted to drive so I headed south to Slo and stopped in King City for breakfast. 2 1st gens followed me in to the parking lot. While they were giving mine a close look they both said the engine really starts running good at about 150,000 miles. Since they both had close to 250,000 I figured they knew what they were talking about.

 

[Hohn]

I think that you have to really work these trucks to get break-in to happen at all.



Did you ever notice how different is the sound of a CTD that's had a life of heavy towing and high EGT?? They sound different-- smoother, quieter, more like a big rig.



I noted this when I dynoed on LaserBob's Superflow. After a good workout (and 1500° EGT), my engine sounded different than it ever had before. It FELT different, too.



Here's the funny part: MPG is up and oil consumption is gone. Now, I didn't really notice it using much oil before (hard to say as I had a turbo drain leak). But the telling thing to me is the blowby tube.



My road draft tube produces very little of anything. In fact, I've taken the puke bottle OFF!! I'll monitor it to see if any crud build up. If not, I'm leaving it off.



JLH

 

[Cummnzpowr]

break in..

Funny thing is, on mine. . it seemed to hold perfect oil level at75k miles a couple months ago. . now that i've put in the #100 plate. . it seems to burn 1/8 out each time, and i see some drippage from the breather tube VS. none before. . maybe it's at it's "pre-pre" break in stage huh?

 

[dodge cummins]

to clarify things most newer cummins engines use oil (or people think its burning oil) is due because the engine isn't broken in because the rings aren't set yet. it isn't burning oil! there is guys on this post who didn't stop having to add oil until 160,000 miles or more. generally why is because they there rig finally did some real hauling or towing. do a search on break ins and you'll see i love my cummins. you won't see any other diesel pickup on the market like this one.

 

[rbattelle]

I've never towed anything or hauled more than a few hundred pounds. At 45k I've never used a single drop of oil between changes.



It is not clear to me whether the engine is "broken in" or not.



-Ryan