# Did my "break-in" break anything?



## DarkJon64 (Oct 29, 2004)

After reading several topics on how break-ins should be done... I'm curious to know what I did to my Sentra 04 SE-R.

I got the car late July 2004 at about 200km. I drove it for 3 days and then BOOM-some guy cut me off at an intersection turning left and i t-boned him. Well after all that I was not at fault and didn't have to pay anything for all the repairs. A few days after the accident the car was finished up again and me and my fiance headed off on a mini-vacation literally right from the body shop. We planned this before we were getting a new car. Anyway, we drove straight through for 14 hours to Alberta and then a week after that the same trip home, putting about 3,000km on in total. (1800 or so miles i guess). Could this have caused any problems? I'm at over 12000 now and haven't noticed anything major.

Thanks


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## chimmike (Oct 17, 2002)

that actually sounds like the perfect way to break it in.


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## AEM Spec V (Feb 8, 2005)

Break in periods are for the weak. As long as you don't go to the track the day you buy your car you're fine. Just avoid the rev limiter for a few more miles until everything seats in properly.


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## muphasta (Aug 12, 2002)

I love it when one person has to tell everyone how pointless the break-in period is.

All I can say is my April '02 produced specV has no issues. And that is suposed to be the worst year of car to have. 

I did break it in "properly" and am happy I did.


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## Zac (Mar 10, 2004)

Well I broke my car in fine and I didnt have any problems. I know people who drove relatively hard and they havent either, mind you they changed the oil at 1k, I didnt. I hear a lot about the piston rings seating and never to use syn initially, and while I understand the concept, many cars roll out of the factory with synthetic oil (generally Mobil 1) already in them, ready to be driven hard. I am starting to think the break in is more for the clutch. I think the break in that was described sounds great and that being gentle on a car initially is a great idea, although it may not be as important as I initially thought.


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## AEM Spec V (Feb 8, 2005)

The second I drove out of the lot I rolled up next to a brand new GTI and smoked it. It was gratifying.


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## Marvin (Oct 16, 2002)

AEM Spec V said:


> The second I drove out of the lot I rolled up next to a brand new GTI and smoked it. It was gratifying.



Sounds like you got lucky. Many people are having issues bc they didn't break it in properly.


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## AEM Spec V (Feb 8, 2005)

I haven't had any issues beyond what others have had; TPS, MAF (my own stupid fault, don't ask LoL), and Transmission.


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## muphasta (Aug 12, 2002)

Did you get the memo on the TPS reports?


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## Ralphieboy57 (Sep 20, 2004)

*Break-in on my 04.*

I drove my Sunburst from the lot straight to Serenity Sound where I had all of the Bolt-ons done. To say the least the car was run hard. From there to DCsports for a header. They used my car to fab there new 4-2-1 drag header. The car only had 381 miles on it. So there were many dyno runs performed on the car. I did let the motor get hot and cool off alot. I also run Moble1 synthetic oil. I havent had any problems! I have 8500 mi on it. I think the key to break in is to do the cooling thing. This way the Aluminum block gets used to expanding and contracting. I heard the 04 had most of the bugs taken out anyhow. :loser:


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## Jess_Spec_V (Jun 21, 2004)

DarkJon64 said:


> Anyway, we drove straight through for 14 hours to Alberta and then a week after that the same trip home, putting about 3,000km on in total. (1800 or so miles i guess). Could this have caused any problems? I'm at over 12000 now and haven't noticed anything major.
> Thanks


Taking a new car for a road trip really is a good way to break it in. As long as you aren't red-lining it every chance you get.  
Running it hard is what hurts, not running it long.
Since you are usually just rollin down the interstate at a steady pace for long hours, you are taking care of the whole 'going easy on the clutch' thing while putting a good amount of miles on the car.


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## droppinbottom (Jun 30, 2003)

most of the break in was probably done before you even got the car if it had miles on it from the dealership. think of it like this do you think the person that test drove that car babyied it? i know i didnt with the one i test drove. if im not mistaken the breakin is only the first couple hundred miles anyway.

dont worry there is nothing you can do at this point


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## skatehard90 (Dec 20, 2004)

AEM Spec V said:


> The second I drove out of the lot I rolled up next to a brand new GTI and smoked it. It was gratifying.


i didn't think the Spec V's beat the GTI's on the line. . . I guess good take off on your part or who ever was driving the GTI was just not 'on the ball'

have a nice day


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## AEM Spec V (Feb 8, 2005)

I haven't run up against another GTI since I've had the car, but I know for sure he would have absolutly no chance now.


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## Bryan200sx (Jan 23, 2003)

AEM Spec V said:


> The second I drove out of the lot I rolled up next to a brand new GTI and smoked it. It was gratifying.



There is no street racing on this forum..... 

any one who dose not properly break in the motor is just dumb...... There is a reason why tell you to do it everything is getting seated right you may not have have problems now but down the line the QR25DE is very sensitive to break-in.


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## AEM Spec V (Feb 8, 2005)

Bryan200sx said:


> There is no street racing on this forum.....
> 
> any one who dose not properly break in the motor is just dumb...... There is a reason why tell you to do it everything is getting seated right you may not have have problems now but down the line the QR25DE is very sensitive to break-in.


And begins the spread of *IGNORANCE*. Let me help you understand...

Nowadays, the piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber. If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ... How can such a small amount of spring tension seal against thousands of PSI (Pounds Per Square Inch) of combustion pressure ?? Of course it can't.

Pistons seal against the tremendous gas pressure via the gas pressure itself. It passes over the top of the ring, and gets behind it to force it outward against the cylinder wall. The problem is that new rings are far from perfect and they must be worn in quite a bit in order to completely seal all the way around the bore. If the gas pressure is strong enough during the engine's first miles of operation, then the entire ring will wear into the cylinder surface, to seal the combustion pressure as well as possible.

The problem with an easy break in is the honed crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly wear down the "peaks" of this roughness, regardless of how hard the engine is run. There's a very small window of opportunity to get the rings to seal really well the first 20 miles. If the rings aren't forced against the walls soon enough, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again.

More importantly, due to the vastly improved metal casting and machining technologies which are now used, tight parts in new engines are not normal. A manufacturing mistake causing a tight clearance is an extremely rare occurrence these days. But, if there is something wrong with the engine clearances from the factory, no amount of gentle running will fix the problem.

But what do I know, I'm DUMB right?  Any questions?


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## Bryan200sx (Jan 23, 2003)

AEM Spec V said:


> And begins the spread of *IGNORANCE*. Let me help you understand...
> 
> Nowadays, the piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber. If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ... How can such a small amount of spring tension seal against thousands of PSI (Pounds Per Square Inch) of combustion pressure ?? Of course it can't.
> 
> ...


Do as you wish..... its better to be safe then sorry. There is a reason they tell you to break it in. Unless you have a degree that can go up agenst what engineers of BMW, Ferarri, Mercedes, NISSAN, and Honda have to say. According to your statement then Bedding the brakes properly, Breaking in the clutch, is all a waste of time. Im sure that you also belive warming up your engine is a waste as well. Sorry man if you take the time to search on these forums you will see that almost every problem with the QR25 is due to inproper "break-in" When they tell you to take it easy the 1st 1000 miles its not just for the engine. You have been on the boards for like a month try reading up more buddy. 

And don't explain how an engine works to me if your still saying that break in are for the weak. Proper break-in combined with good mantinace is what makes an engine run for over 100K and if you don't belive me my little GA has OEM compresion with a 1-2 PSI variance between cylinders. if your engine makes it to 109XXX miles see where your compression is i highly doubt that it will be anywhere near that good.


( mind the spelling its early)


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## Hydrolock (Feb 18, 2005)

AEM Spec V said:


> And begins the spread of *IGNORANCE*. Let me help you understand...
> 
> Nowadays, the piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber. If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ... How can such a small amount of spring tension seal against thousands of PSI (Pounds Per Square Inch) of combustion pressure ?? Of course it can't.
> 
> ...


Not very impressed by people who like to show-off sorry. I just think you tryed to hard right there. Anyways, break in period is to ENSURE a smoothe running engine, as opposed to beating the shit out of it and hoping for the best. I've seen more to a few overly eager people to put their fresh project on the dyno and get some numbers, have fun with bent valves and seized pistons.


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## IanH (Feb 11, 2003)

DarkJon64 said:


> After reading several topics on how break-ins should be done... I'm curious to know what I did to my Sentra 04 SE-R.
> 
> I got the car late July 2004 at about 200km. I drove it for 3 days and then BOOM-some guy cut me off at an intersection turning left and i t-boned him. Well after all that I was not at fault and didn't have to pay anything for all the repairs. A few days after the accident the car was finished up again and me and my fiance headed off on a mini-vacation literally right from the body shop. We planned this before we were getting a new car. Anyway, we drove straight through for 14 hours to Alberta and then a week after that the same trip home, putting about 3,000km on in total. (1800 or so miles i guess). Could this have caused any problems? I'm at over 12000 now and haven't noticed anything major.
> 
> Thanks


Well I drove my new Sentra in 97 from Dallas to Albuquerque, to Las Vagas, Death valley and back. This was more than 2,500 + miles. Its now at 72,000 and no problems other than wear items and a weak clutch. All original Engine etc. So no, if you did not push the car hard and rev it to the red line I believe it will be fine.
Good luck.


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## AEM Spec V (Feb 8, 2005)

I've only been a member on THIS forum for 1 month, a member on all other B15 forums for 3+ years, there is a reason I am a senior member with 5 stars on those forums. Don't discredit someone based on their time on a board, it is no way to base knowledge.

I am not saying its better to mash on the gas the second you get the car, all I'm saying is there is a lot of misinformation floating around that needs to be corrected. Sure, most people say break it in easy, but they don't understand WHY.

My car was driving hard from the begining and is tracked 5 times a year as well as autocrossed countless times a year, no problems other than basic recall work and a few common problems among other B15 owners. To each his own.


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## Chillboy (Oct 8, 2003)

Varying rpms is the way to break in and make your rings seal properly. And not just the Spec. 
When I got my 2K1 Pathfinder I was told not to use cruise control for the first couple thousand miles. When I had my boat motor bored over with new pistons the mechanic told me the same thing about not staying at one speed too long til the rings set. Which is quite fun in a boat rated for 50hp with an 85 bored to a 115 
I did this in my Spec too but I have an early 02 and those hard rings never sealed right. My pistons were black, my crankshaft was scored after 10K miles. It seemed to still run good, but the insides said not for long. The said rings were only used on first run Specs so don't worry too much (unless you have one).


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