Engine Break-in

All this tells me is that there is no meaningful consensus on what's 'right'. I know I've never taken any special care, beyond not being crazy, with my new cars and never experience any problems.

I think it's pretty cool cause you can pretty much do what you like and know you'll still get good life out of it.

 

I am usually more concerened with gentle, progressively higher heat cycles, than I am with high RPM break in. Heat cycling "breaks in" everything, not just cylinders and bores. I have used this method on my bikes for years, and I like to apply it to my off-the-lot auto purchases as well. Progressive warming and cooling of the metal parts allows them to "find their home", but this is just my opinion as a lifelong mechanic.

 

I can't speak for 2nd gens (not sure it matters anyway) but with older Toyotas I've had , after a rebuild, its start it up & go thru the gears at full throttle , it even said it explicably in repair manual, your mention of "progressive warming " isn't the best way to break in an engine, you aren't trying to temper the metals, any manufacturers reference to "breaking in" is really meaning SEATING THE RINGS, period. Usually with most engines the rings seat almost immediately..

If any engine has been rebuilt with OEM standard parts & all machining/building is done correctly, there is absolutely no reason whatsoever that motor can't be started & driven aggressively (full throttle) right from the get....

 

Heat cycling is *not* about tempering metals. It is about creating conditions that will allow bearings, shafts, and bushings to shift slightly to find their "most comfortable" position. These items can be left with undesirable preload during assembly. Heating and cooling cycles allow them to shift just a bit to where they run best.
Overall, it is not a big deal, though, as they will all find their way "home" eventually. That said, I am not a fan of the "Hard" break-in procedure, especially if the motor (and tranny, transfer case, differentials, etc.) is not at full operating temperature.
These trucks are well built and engineered. I doubt that any of these methods will have a significant difference in terms of longevity or performance on a normal stock street vehicle. Everybody here can chose whatever method they are most comfortable with.

 

Really? My tuner/builder does hard break in on every engine he builds including his 8 second civic.

 

From a Mobile One rep "Don't put synthetic oil in the engine until you have 10,000 miles on the engine or it will never break in" But maybe this doesn't matter if the engines really are broken in at the factory.

 

That Mobil One rep may have been a fake.

Myth: You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.

Reality: You can start using Mobil 1 in new vehicles at any time, even in brand new vehicles.

http://www.mobiloil.com/USA-English/MotorOil/Synthetics/Myths.aspx

 

My Chev Duramax I bought in 2006 had 15km on it when I picked it up...Immediately went out and drove it hard...a few pulls up to the limiter and aggressive driving at varied rpms and selective gearing...had 490,000km on it last time I spoke to the last owner and never had an issue with the engine or transmission. The built low compression turbo engine in my BMW M3 did a dyno pull of 600rwhp on its first run up and successively put down 800rwhp...engine has been perfect ever since.

The Tacoma which I picked out from the dealership had about 38km on it when i went for the test drive...I ended the test drive with 93km on it and all of it was aggressive driving...up to the limiter, engine brake coasting, varied rpms, etc...nothing severly abusive just making sure the rings and everything seat properly right now rather than scar things...will be doing an oil change after about 400km on it. From my knowledge it already has synthetic in the engine. Broke in all my quads and other machines this way. We will see how this one turns out.

 

No doubt this guy was probably a fake. Considering that Mobil One is put in Porsche, Vette's etc , right from the factory. Makes no sense. MJEFF

 

the whole point of break-in is to determine where the peak performance of your engine will be in it's life cycle, the manufacturer knows when and how to extend it's peak perfomance.

Porsche says to restrict rpms over 4000rpm out of a 7400rpm redline. Can you take your car straight to the racetrack? No problem but your engine will peak earlier and have a shorter peak than one following manufacturer recomendation. The porsche engineer says by breaking in the engine by their proceedure will hit peak engine efficiency at 30,000 miles.

This is done by slowly incrimenting periods of high heat to the engine.

Fact: The bearing clearances are "tight" when new.
Fact: At this state by heating this area by heavy load and rpm will expand the journals from the heat and cause scoring

You are breaking in the engine to avoid scoring of the bearing surfaces. To best avoid this you must start easily and slowly increase heat. Porsche recommends 2000 miles but for me 1500 was a better schedule as I do not drive the car often.


Also during initial start up, this all must be sacrificed to seat the piston rings, that is why that is in the service manual. it is a sacrifice you must make it is not a pass to discredit all of the above.

BTW porsche goes into detail with their process and made it very public

They "break-in" their motors at the factory on a variable load dyno for 30 min including warmup.

My opinion is this is to provide ideal break-in proceedure impossible to be done with the engine in the car and possibly to extend engine performance to the end of warranty for ppl taking their cars straight to the track

 

Question??? buying a new truck 1600 miles away. Originally had time to break it in before the drive home, but now my time is drasticaly limited. I may have to head home on a 1600 mile drive within a day or two after purchase. Concerned about break-in, should I try to avoid the hwy for at least the first 500 miles? does it matter with the pre factory break-in? Any theories? Thanks...

 

I've wouldn't worry, I've heard avoid cruise control and vary the speed.

 

Huh, what? You don't use your clutch after 1st gear?

 

Change engine speed every 30 min by gear or mph. Don't go over 3500 rpm

 

With all due respect we're not driving porches & you forgot to mention the porche recommendation of valve adjustments. (constant & on going for earlier air cooled motors)

Porche/VW are very maint/tune up specific & not very applicable to other manufacturers

 

IMHO I think it does relate especially as Toyota runs tighter bearing clearances.
Also I didn't mention valve train as I feel it is completely unrelated to the rotating assembly break in

 

well if everything goes as planned i'm getting my 2012 taco in a couple days.. what is the engine breakin suggestion these days.. i will have to drive about 40 miles (most highway) to get it home from the dealer. do i have to vary the speed/rpm?..

 

Is there evidence of this (documentation)?

I ask because I once compared the bearing clearances and tolerances between a late-1990s engine and an early-1960s engine from the same manufacturer, and the clearances and tolerances were almost identical between the years (well within 10% of each other).

This makes me suspicious of any similar claims. The best documentation commonly available would be engine specs from factory service manuals.