Breaking-in the engine

[FD3S]

When exactly is the engine broken-in? I know the manual says around 1200 miles, but I'm sure it various. Are there any signs that can identify this? Maybe a certain engine sound or response?

[lain]

You don't really have to break in the new motors, they are built differently now (at least this is what the dealership told me). I tried to break it in but i only got to about 600 miles where I couldn't take it anymore and just drove how I felt like driving.

Most of the time i drive shifting at around 2k-2.5k rpms but there are times when i just get bored.

[Rockhound]

You'll hear a buzzer go off, and then you're good to go.

Not really, but in all seriousness, engine break-in is, from my limited research, a topic dominated by hearsay and tradition, but not much hard proof.

Some folks promote giving the engine a full "work-out" during the break-in period, while others (Nissan, included) suggest that you should take it easy until you've got a little over 1000 miles on the clock. Like Lain said, just driving normal and avoiding high revs should do the trick. Other than that, however, there's no distinct change in engine performance or operating characteristics that really signifies that the break-in is "complete".

To me, the fact that gas mileage continues to increase for many cars possibly beyond the 10,000 mile mark indicates that changes of some magnitude continue to take place well beyond the manufacturer's recommended break in schedule.

[boxcarbill]

your mill will get into bed with you and whisper in your ear I'm all broke in now honey.

[Rockhound]

your mill will get into bed with you and whisper in your ear I'm all broke in now honey.

Creepy.

[nissantech06]

To me, the fact that gas mileage continues to increase for many cars possibly beyond the 10,000 mile mark indicates that changes of some magnitude continue to take place well beyond the manufacturer's recommended break in schedule.

Indubitably.

Anywho, this is the same reason for the exhaust tone change over 10,000 miles. This is why I laugh when I see people with exhausts on cars with less than 2,000 miles...not a laugh of "haha' but a laugh because I know the reduction of backpressure isn't good for a barely-broken in engine.

[zgol]

I know the reduction of backpressure isn't good for a barely-broken in engine.

Can you explain this? I'm not doubting you, just curious. Thanks

[nissantech06]

Can you explain this? I'm not doubting you, just curious. Thanks

I'd be happy to. Your engine parts are still new, backpressure is established on a car to scavenge spent exhaust gasses out of the head. If you notice, over time, your exhaust note will change as the car is driven more. I can't GUARANTEE what mileage, but after about 10,000 or so, your engine is fully broken-in to the point where your HP, gas mileage, and tone should be pretty level across the board, as far as consistency is concerned. Well, if you don't allow the parts in your engine to settle, meaning putting a free-er flowing exhaust on the car, your new valves will start to heat up quicker, and they might not seat in your head the way they should.

[nissantech06]

Can you explain this? I'm not doubting you, just curious. Thanks

I'd be happy to. Your engine parts are still new, backpressure is established on a car to scavenge spent exhaust gasses out of the head. If you notice, over time, your exhaust note will change as the car is driven more. I can't GUARANTEE what mileage, but after about 10,000 or so, your engine is fully broken-in to the point where your HP, gas mileage, and tone should be pretty level across the board, as far as consistency is concerned. Well, if you don't allow the parts in your engine to settle, meaning putting a free-er flowing exhaust on the car, your new valves will start to heat up quicker, and they might not seat in your head the way they should.

I don't know EVERYTHING...but I've done enough research and have had enough work and read enough books from school to come to this conclusion.

[dopey]

After giving it a little bit of a spurt I took it easy for the first 1500km and then began thrashing the crap out of it just to break it in good and proper.

22,000km old and hasn't skipped a beat.

Can't treat em too nice or they'll be a dog for the rest of their life