how to break in cars

T

tomkit

Member
the general consensus is to break cars in easy because (i think) the moving parts in the engine/cylinder have small pieces of metal that break off when first driven which can cause damage to the engine. but in another post someone mentioned that cars need to be broke in by flooring them (http://www.mototuneusa.com/break_in_secrets.htm). are there any professionals that have any knowledge on this?

*fixed link
 
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I'm not sure of what "professionals" you're asking for input from. I'm certainly no professional, but I read the info, and while it made sense, I'm not sure of the absolute nature of all of his statements and/or conclusions.

What I can say is this: That as a fairly knowledgable guy, I've had my chance(s) to break in several motors, including one rotary.

For the first 500 miles, I will drive normally, with occasional (and frequent) runs up to max horsepower and torque revs under load. These are done in the regular course of driving. Precautions include (1) never redlining (2) conscientious attention to temperature (3) never prolonging max load and rpm conditions for an extended period of time.

The only engine failure I ever experienced was in the rotary (1977 RX3-SP) 13b after 124k miles. This was the same motor that I drove 185 miles in an hour and a half. (back in my wild and crazy days trying to catch a plane in Billings, MT) Finally the apex seals leaked as the car got older.

Short answer from my perspective - Hit it, but judiciously.
 
G-Papi said:
For the first 500 miles, I will drive normally, with occasional (and frequent) runs up to max horsepower and torque revs under load. These are done in the regular course of driving. Precautions include (1) never redlining (2) conscientious attention to temperature (3) never prolonging max load and rpm conditions for an extended period of time.
Click to expand...

That's about what I usually do. I'll only add that I probably flogged it a little more frequently then G-Papi but always waited till the engine was fully warmed up.
 
While it does make sense, I am putting my money on the idea the difference in engine life expectancy and preformance is negligable if any. I'll feel good about my moderatly light break in period.
 
I've always been told;

"break it in the way your going to be driving it."

I broke in my bike damn hard and she runs better than most others. I was making another 5whp (that's a good amount on a sportbike)compared to another stock SV650S that was broken in lightly.
 
endurance race engines are broken in hard, I did the same for my last couple cars with great ring seal. My civic, i broke in with synthetic and light driving and the lost half quart of oil every 3k miles. Msp was broken in hard with dino to 9k, and lost no noticable oil.

anyways who really keeps their cars over 100k miles anymore? don't worry about it.
 
Break in

I've always used a flexible metal yard stick with a notch on the end to get in between the window and the door weather striping. On newer cars this ruins the lock linkage so the key will no longer open the door. Now I keep some plastic wedges on hand to spread the door frame to body gap enough to insert the yard stick and pull inside lock release. Often a yard stick is too short and may need a twist at the end notch. MartyD
 
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Well, The dealership I go to runs there cars hard on test drives. When I bought my PR5 it already had 95 miles on it. Same with my CX-7 it had 93 miles on it. I rather buy a new car with a few miles on it, knowing the guys at the dealership run the hell out it. I have not had any problems with either car since I've bought them. There was one instance were I drove a Mazda 3 brand new had 1 mile on the ODO. I drove that puppy hard and the gearbox broke on it.
 
aw, darn, I thought this was going to be a thread about "how to break into cars"

(ripped)
 
Is this a new car or a rebuilt engine? There's a difference.

If new, you should not hold a steady speed and rpm for a long period of time. N No fast starts from traffic lights, no hard stops, as in standing on the brakes or slamming on the brakes. Drive at moderate speeds and RPMs for the first 1000 miles, varying your speed and RPM. Do not use the cruise control. Do not run the engine above 3000rpm for the first 600 miles. You want to seat the rings so it doesn't use oil. The engine is "tight" and needs time to losen up. Some metal bits will come off in the cylinders as the rings seat. They will be flushed out with the oil change.

Remember most new cars have an on-board computer which adjusts the engine and other controls to your driving style and they also have a "black box" which records what happens -- just before a wreck, during, and just after it -- so the factory will know what you were doing when it happened. The "black Box" cannot be disabled, if you try to do that the car will not start.
 
JimboNC said:
Is this a new car or a rebuilt engine? There's a difference.

If new, you should not hold a steady speed and rpm for a long period of time. N No fast starts from traffic lights, no hard stops, as in standing on the brakes or slamming on the brakes. Drive at moderate speeds and RPMs for the first 1000 miles, varying your speed and RPM. Do not use the cruise control. Do not run the engine above 3000rpm for the first 600 miles. You want to seat the rings so it doesn't use oil. The engine is "tight" and needs time to losen up. Some metal bits will come off in the cylinders as the rings seat. They will be flushed out with the oil change.

Remember most new cars have an on-board computer which adjusts the engine and other controls to your driving style and they also have a "black box" which records what happens -- just before a wreck, during, and just after it -- so the factory will know what you were doing when it happened. The "black Box" cannot be disabled, if you try to do that the car will not start.
Click to expand...


Potentially wrong info. New engines are not "tight" and do not need time to "loosen up".

http://www.mototuneusa.com/break_in_secrets.htm
 
lol.. the 2nd day i picked up the car i went to a camping trip put 800 kms on it and drove 140km/h... car has 4200 kms on it.. car drives fine.. and had a fire in the engine bay too!.. lol.. sigh..
 
Just my two cents on break-in.

I do it the "hard" way. I make sure the vehicle is properly warmed up before driving it hard, but once it is properly warmed up (and I'm doing this the day I pick it up, IE: with as low mileage as possible), I'll take it at half throttle up to higher speed (70-80 mph), then slow down carefully (one item you dont break-in hard are your brakes). Then, another half throttle run up to similar speeds. Let it cool down a bit, then take it up to higher speeds again, this time at full throttle.

Make sure you're warming it up properly (20 minutes of regular driving before-hand, and make sure you're not being overly aggressive (although all of my cars have been MT, so in an AT it's not too big of an issue).

This method worked great for me in my '04 S2000. At a local dyno day, my car put down 225 WHP stock, where-as the couple of other s2000's attending were at 195 to 205 WHP, both on the "by the book" break-in method.
 
If you do the "Hard" way shouldnt you also do an oil change real soon around 600miles/1000km to get the metal out?

Thanks
 
assman said:
If you do the "Hard" way shouldnt you also do an oil change real soon around 600miles/1000km to get the metal out?

Thanks
Click to expand...

That applies to a new or rebuilt, never rotated engine.


In this case, what Ive done and always worked for me:

1. Its good to keep it idling for a few hours a day for a couple of days, check for noises, oil pressure and water temps;
2. Check and change oil. Rev it up to 3k for a couple of seconds and lsiten to clapping noises (rod knock, cams, etc)
3. After that, drive it normally but dont rev higher than 3K rpms for the first few days, then 4k rpms for a week and change oil. Start spooling the turbo, a couple of psi's will do fine.
4. Drive normally for a month. Boosting and stuff, change oil only if necesary. Do a leak test on cylinders, inspect sparks and stuff.
5. Drive hard...done

Always use premium gas to prevent ping, always checking for noises, pressure, temps, etc.

And thats true about the ring seals, you will have blowby gases in the first hours of the engine life, but rings are not everything. I do all of this because of the oil seals, bearing and cam clearance.
 
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