What is the correct procedure for breaking in a new motor? Just received a new 5.4L motor after 69000km. The service dept was no help.
They told me to just drive it easy, I asked them for how long? They just had a stunned look on there face and shrugged there shoulders. It's hard to find a good FORD service dept in central Alberta.
When I got my new truck in 2009, I varied the speed as per booklet but I didn't stay with their oil change schedule. I changed the oil/filter every 3K miles till I had about 30K on the truck, now at 75K miles runs perfect. Nor did I tow any real weight till about 8K miles. Chris
Break-in used to be something that was done by hard-and-fast rules. these days, the way engines are manufactured is different, meaning that the traditional rules may not apply. Meaning that everyone disagrees about the rules.
the only thing that people seem to agree on is that you need to vary RPM for "a while."
some of the people I respect most suggest driving vigorously right from the first day, lots of hard starts. Some people like to baby it for a while.
If it was mine, I'd drive like I stole it from the first day.