The manual is vague. I was on the Oil Drop Forums and found an interesting post that I will share with you. I have always just taken it easy for the first 1000 miles or so and then did an oil change and at that point driven a little more spirited. How do you all recommend breaking in a new 3 liter v6 diesel???

Here is the post from the forum

Well, the manual is rather vague about break-in procedures, and with only 400 miles you haven't yet gone through a full tank. I'm following a break-in procedure recommended for Volkswagen TDI's by a experienced mechanic. I modified it somewhat for the Jeep's M-B engine:

Quote:

Break-in routine for Jeeps with Mercedes-Benz OM642 3.0L turbodiesel engine by boxcab, as adapted from recommendations by TDIClub.com's member Drivbiwire for Volkswagen TDIs.

Rules that apply for the life of the car:

- When the engine is cold (below the first mark above the base of the temp gage) rev the engine to at least 2,200 rpms when driving. Avoid idling.

- When the engine is at or approaching normal temperature (above the first white mark to middle of the gauge) rev the engine to at least 2,700 rpms. The reason for this is to keep the turbo on boost, clear the VGT guide vanes and apply firm pressure to the rings for optimal sealing against blow-by gasses. The rings need the boost to seal since its a turbo-charged engine, Babying the engine is detrimental and will lead to issues with compression and cylinder glazing if done so for very long.

Break-in procedure

1. First 1,000 miles:

- Keep maximum rpm below 3,400. Avoid steady rpm. Frequent firm application of power is strongly recomended up to 3,400 rpm. Avoid the use of cruise control so that you naturally fluctuate the power with your foot.

2. 1,000-6,000 miles:

- Use the full 4,500 rpm power range. Avoid steady rpm. Avoid the use of cruise control. Frequent application of full throttle is recomended to help seat the rings. City driving is ideal for breaking in a CRD due to frequent stops and acceleration. Once you get to 6,000 miles change the oil and perform your first service per the manual.

3. 6,000-12,000 miles:

- Use of the cruise control is okay at this point since most of the initial break in has occured. Continue to use occasional full throttle accelerations to continue to seat the rings. You will notice the engine becoming slightly louder during this phase due to less friction from the engine breaking-in (it's normal for a diesel to become louder under lighter loads). If you're going on a long drive and are using the cruise control, every so often push the pedal firmly to the floor (don't stomp on it) to accelerate up above your previous speed by about 20 - 30 mph, then coast back down to your preset speed.

4. 12,000-60,000 miles:

- This is when the rest of the break-in occurs. It will take at least 60,000 miles to reach peak compression pressure. For the most part, once you get to 12,000 miles your compression will close to peak, meaning that most of the break-in has occured.

I hope this helps. The main thing is to drive spiritedly, but without jack-rabbit starts and recklessness. Make that engine work!


Let me know what you think
Dieselfan

 

That's pretty much it. Don't baby it but don't abuse it.

 

What would you consider abuse?

 

Flooring it everywhere you go and driving like a teenager.