Engine Break-in

[S4toSTI]

On my audi forum when someone asks about breaking in their new car someone usually posts this (http://www.mototuneusa.com/break_in_secrets.htm) link. Anyone else have some good references for new engine break in. I know it is a very tricky and highly disputed internet subject but the more info new car buyers have the better.

[2point4DSM]

On my audi forum when someone asks about breaking in their new car someone usually posts this (http://www.mototuneusa.com/break_in_secrets.htm) link.

I've seen this before and the subject was debated on a DSM forum. My feeling is that there is a lot of mis-information on that site. I especially like how he compares a brand new piston to one that is used and tries to pawn it off as evidence of his break-in technique.

Check out the first pic of two pistons coming from a Honda F3; wouldn't it make sense for the top side of the piston before the first ring to look like the corresponding section of piston on the left since he is talking about ring seal. (ps. there is no ring on the very top of a piston so there should be some kind of combustion byproduct there ).

What I've done over the years is talked to people at machine shops and other mechanics that are into taking apart and building motors on a regular basis and the consensus is that it is better to break a motor in slowly so if there are any problems things can be fixed.

Most importantly, does any one know of any manufacturer's manual that says to beat on the motor to break it in. Any one believe multi-billion dollar companies that have tons more experience in racing and building motors is going to give bad advice in their owner's manual.

[blkbomber01]

they say to take it easy for the first xxx miles.... but i believe that if its built right you can start it up and romp on the gas, unless you have a new turbo or sc, they i would follow the break in directions

[Safir]

My engine builder suggests 500 "nice" miles with 30wt non-detergent oil. Makes sense to me, so it's what I go with.

as for a new car, which will come with oil in it, 500 "nice" miles followed by an oil change at 1,000 miles. or so.

[the mike]

Subaru recommends keeping the RPMs under 4000 RPM for the first 1000 miles and varying the RPMs, that is not keeping the RPMs at a certain speed(cruising on 95 or 295). They also say never to go to full throttle while breaking in the motor.

Mitsubishi is 600 miles I believe.


As soon as my 04 WRX hit 1001 miles, it went WOT.:mrgreen:.

[UnderPoweredRS]

My motor came broken in :-D

[2point4DSM]

My engine builder suggests 500 "nice" miles with 30wt non-detergent oil. Makes sense to me, so it's what I go with.

This (along with the other stuff that has already been mentioned) brings up a good point....

Break-in is specific to machining techniques. Some manufacturers are able to build a motor so well now that there is virtually no break-in period for rings. And the advice found in the owner's manual is really meant for the whole car in general to help take care of the brakes, tranny, suspension, ecu, etc.

And different machine shops might recommend different ways to break-in a motor depending on their techniques and experiences. So if you buy a new car then go by the manual's recommendations but if you have a motor rebuilt then go with the machine shop's recommendations.

There are also some sites out there that talk about oil contamination in certain motors, found in new cars, during the break-in process. I think there are interesting facts found on them which helps back the idea that it is better to break-in a motor nice and easy. Because if you run the motor hard trying to seat the rings what kind of abuse are the bearings taking.

[the mike]

Also, I have heard to not run synthetic during break in if your car doesn't come with a factory synthetic fill.

[MuddyREX]

I was very tender with my car before 1000 miles.

I also heard that you should swap out the break-in oil before the 3000 miles because it doesn't have very good long-term characteristics.

[S4toSTI]

I was very tender with my car before 1000 miles.

I also heard that you should swap out the break-in oil before the 3000 miles because it doesn't have very good long-term characteristics.
I took out that oil after 500 but in another batch of regular oil then at 2000 i started to use synthetic.

[Raven18940]

Just to show how things can vary, Saab recommends a loose but long break-in period. They say for the first 5000 miles don't go completely full throttle or above 5000 (fuel-cut is 6500). We changed the oil at like 2500 miles to synthetic and it's been running it ever since. Now I drive it like I stole it all the time and it runs great, actually seems to like it.

[MrDibbs19]

i just got my new 06 acura rsx-s... about 200 "easy" miles... but from what the rsx-s manual says, it says i should do 600 miles and it will be broken in... other tuners/mechanics i work with say drive it nice for a 1,000 miles...

[poolmike]

For old Chevy V8's its simple. Run it for 15-20 minutes at high idle 1500-2000 rpms, change the oil. Take the vehicle out on the road and stand on the stupid pedal! Always works for me.