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How to "break in" a 5.7L HEMI? (Moved)

33K views 34 replies 17 participants last post by  stevesrt8 
#1 · (Edited)
Just got my 300C as many of you know, it only has 73 miles. Now I know with a 4-stroke jetski you should ride it pretty hard to make sure the rings seat real good, but what about a car? Will it be better for me to drive it like I stole it, or normal, or go into complete grandma mode?:pat:
 
#3 ·
I agree with the nice and easy part for the first few hundred miles and varying the speed and rpm a bit. The problem your going to have is once this baby gets running a little freerer is keeping your foot out of it. Intoxicating is a understatement.
 
#5 ·
This is from the '07 manual. I was very pleased to read that "brief full-throttle..." part. I took full advantage, "within the limits of local traffic laws" ...of course!

Drive moderately during the first 300 miles (500 km). After the initial 60 miles (100 km), speeds up to 50 or 55 mph (80 or 90 km/h) are desirable. While cruising, brief full-throttle acceleration, within the limits of local traffic laws, contributes to a good break-in. Wide-open throttle acceleration in low gear can be detrimental and should be avoided.
 
#6 ·
nah

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

read that link and then tell me what you think.

Break in is an old myth. Modern manufacturing and assembly has eliminated the engine needing a genuine break in procedure.

There are driveline parts that still benefit, that's why the first gear limitation.

We have a professional 3rd gen engine builder in the family and he says the rotating assembly is either right or not, and the rings are seated in a very short time, like minutes.

Drive it hard and you'll actually have more power.
 
#7 ·
Drive it hard and you'll actually have more power.
This is true, I have seen the proof from two mates, David and Ashley who bought the exact same TICKFORD AU XR6 ute at the exact time and both did their own thing, the mate Ashley who drove it like he stole it actually got more RWHP at a local dyno day, this was a year + after owning them, mind you his ute had more rattles too :biggrin: :biggrin:
 
#10 ·
from the 2008 300 manual:


ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine in
your new vehicle.
Drive moderately during the first 300 miles (500 km).
After the initial 60 miles (100 km), speeds up to 50 or 55
mph (80 or 90 km/h) are desirable.
While cruising, brief full-throttle acceleration, within the
limits of local traffic laws, contributes to a good break-in.
Wide-open throttle acceleration in low gear can be detrimental
and should be avoided.
The engine oil installed in the engine at the factory is a
high quality energy conserving type lubricant. Oil
changes should be consistent with anticipated climate
conditions under which vehicle operations will occur.
The recommended viscosity and quality grades are
shown in Section 7 of this manual. NON-DETERGENT
OR STRAIGHT MINERAL OILS MUST NEVER BE
USED.
76: THINGS TO KNOW BEFORE STARTING YOUR VEHICLE
A new engine may consume some oil during its first few
thousand miles (kilometers) of operation. This should be
considered as a normal part of the break-in and not
interpreted as an indication of difficulty.
 
#12 ·
Pretty much seems like you should avoid low gear hard acceleration from what I read. So I think that the 55 and hammer it idea should do you pretty well.
My wife broke her 07 Hybrid Camry in the wife/hybrid way by barely touching the throttle. She came to me complaining that she couldn't get the engine to turn on while driving very often and thus couldn't break in the motor. So I took it out on the highway and did it my way ;) Car is still perfect
 
#27 ·
Haha, I tried getting her into something with a little more OOMPH! But she was firm in her hybrid ways.
This summer when gas was $4+/gallon... you wouldn't believe the agony she put me through. lol:pat: "My car gets 600 miles to a tank, blah blah blah blah blah." Grrrrr!!
 
#16 · (Edited)
Wait, question before this thread dwindles into nowhere land, how often should I do the hammer at 50 thing? Like every 10 miles I drive, everytime I get on an open road where I can do that (which is about 3 times a week)?
 
#17 ·
Remember, we're only talking about 300 miles, total. Not like the 500 - 2000 miles of yesteryear.

If you haven't already, you'll find that 50 - 70 at full throttle is very brief indeed. I probably 'kicked' mine a half a dozen times during that first 300 miles... and closer to 85 than 70. I didn't have much opportunity either.

The autostick is the semi-manual shifting you get when moving the shifter left and right - left for down shifts, right for up... hold it right for a second to pop back into Drive.
 
#18 ·
Just beat on it. It will survive. Just make sure there is oil in the crank case. I drove a 6.1 07 SRT 3000 miles right off the show room floor. Average 100mph on lots of interstates. My 5.7L hemi in my ram, I did 8k in the first month. mostly easy miles. The car engine stopped using oil at around 8k mark and the ram was around 20k. Most people just trade off their vehicle before the motor goes boom, the rest of the car would be worn out prior to a complete engine failure. Just keep oil in the crank case and gas in the fuel tank. They are thirsty during first break in.
 
#20 ·
I follow a procedure that Bobby Allison, (famous ex-Nascar racer) spelled out on an interview I saw years ago. He would run the engines up to redline on a frequent basis, but in a controlled, relatively slow basis. In other words, he would not totally beat on the engine, but rather make sure it was run through the entire RPM range frequently. He would vary the rate that the engine would reach peak RPM as well.
 
#21 ·
I left the lot like i stole it,If its a Hemi drive it like a Hemi
 
#22 ·
FYI, I know it's not a 300 but there is an insert card in my 09 Challenger SRT's owners manual that says to do the break in time of 500 miles and lists what to do. I guess it's up to the individual owner to decide about their car.
 
#25 ·
My view on the breakin period stays the same for both my motorcycle and car. I agree with those that say a new engine today is a lot better made, but it seems to me that I can feel them getting loose between 400 to 500 miles. That is the point when I start pushing hard for short spurts and bringing the revs up. Hard for me to say who is correct on this one, but I just feel guilty about pushing a new engine hard initially. Love the way the Hemi pulls once they break in, a pleasure to drive for sure.
 
#26 ·
Motor last longer than 4 years or 200000miles. By that time everyone has grow tired or used up the car and buy a new car. Just drive the car.
 
#28 · (Edited)
I took delivery on my car today, absolutely stunning. I was going 60 and ran her open till 80 on my way home, but only one time (heavy traffic, too much for my feet ;) ) The sunroof came out perfect and I have officialy decided I am not going to change a single thing about the car, its stunning! So glad I bought this car, I say better than the dayum STS anyday! :)

The tint came out great too, not to dark, but not to light. I love it, I also love how the spoiler is molded into the trunk lid, and how the hood comes down more over the headlights to give it that aggresive look compared to earlier model 300C's.

God it's beutiful, its been a long time since we owned such a car. Thanks guys for somewhat talking us into looking at them more seriously!:D
 
#33 ·
Just read the part where the manual says it's detrimental to be in low gear/high rpm's.


I have already accidently kind of done this a couple of times already (the worst was 4000 rpm in 1st gear....the other time or two was probably around 3000 rpm). I used the autostick to slow down at toll booths and forgot to put it back into drive when the radio was turned up. She only had around 700 miles on it. What do you guys think? Sell it? Get a new one? :)
 
#34 ·
Bump! Come on people -- I would really like some opinions on this matter. Thanks, Jordan



Just read the part where the manual says it's detrimental to be in low gear/high rpm's.


I have already accidently kind of done this a couple of times already (the worst was 4000 rpm in 1st gear....the other time or two was probably around 3000 rpm). I used the autostick to slow down at toll booths and forgot to put it back into drive when the radio was turned up. She only had around 700 miles on it. What do you guys think? Sell it? Get a new one? :)
 
#35 ·
easy...

easy there, Jordan. Take a Valium or something!

Please go back and read the entire thread. Click on the link provided. Learn the info.

Now note there is NO WAY you harmed your car. It is proven fact that cars driven aggressively during the so called "break in" make more power and run better than cars "babied".

So let that Hemi breathe! Get on it!
 
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