1000 Mile Engine Break-In: How Critical?

[GWA1]

My new Explorer should be in this week. Is there a speed that Ford recommends you stay under while breaking in the new engine? and if so, for how many miles?

Owners Guide says

BREAKING-IN YOUR VEHICLE
Your vehicle does not need an extensive break-in. Try not to drive
continuously at the same speed for the first 1,000 miles (1,600 km) of
new vehicle operation. Vary your speed frequently in order to give the
moving parts a chance to break in.
Drive your new vehicle at least 1,000 miles (1,600 km) before towing a
trailer.

 

[GregV8]

No matter if they say there is no break in period. I grew up old school.
I drove it very gently during the first 1,000 miles. Varying speeds, varying rpm's (but mainly lows).

 

[Prosecutor]

Engine break-in question

Is there going to be any problems with full-throttle starts during the engine break-in period? I wanted to thoroughly test my new Explorer before my wife and I complete the sale (it is a factory order), but did not want to do anything that could damage the engine before it is ready. I read where you should vary engine speed and not tow anything for the first 1k miles, but it does not say anything about the throttle.

 

[1995E]

No problems so far. I went 5k RPM when I hit 500 miles. Since it said vary your RPMs, I did just that. Tried every RPM there was. Although, I heard it's not good on your gaskets or something if you push it too hard before break in.

 

[donm527]

yeah, i would wait until at least 500 miles to start hitting the pedal to the metal

normal driving... varying speeds and loads. letting it go through normal heat cycles. you dont want constant speed for proper break in of parts like the pistons, cylinders, rings. thats why engine builders dont put synthetic from the start... cylinders/rings break in too smooth and they will not retain oil properly. hammer the sucker hard and you may end up scoring the pistons/cylinders.

personally i try to keep it normal til 1000 miles then start pushing it harder. i'm almost at 4000 miles and can feel it's different than when it was the first day. gonna put in full synthetic soon at this point.

good luck.

No problems so far. I went 5k RPM when I hit 500 miles. Since it said vary your RPMs, I did just that. Tried every RPM there was. Although, I heard it's not good on your gaskets or something if you push it too hard before break in.

 

[Bill #5 Explorer]

Make sure the engine is up to full operating temps before full throttle accelerations, and after the break in process is completed.

 

[incredibleman]

Letting off the gas after being at a steady engine speed helps bring oil to the top of the cylinders.

Umm... if oil wasn't getting there already, wouldn't a typical highway trip destroy the engine? sorry, I'm not trying to be a knob, it just doesn't make sense to me.

 

[blueoval9erlifer]

ive been told varying stories about break in from the old drive it as fast as she'll go for 5 to 10 miles then turn around and do it again to take it easy and dont over rev it, from what i learned as a child with multiple rebuilt engines my father did was to lug it up hill and let the engine brake going down hill, also changing speeds is a good idea, if youve ever owned a car that is comfortable driving at 60 but not so much at 55 or 65 its probably because the 1st owner bought it and set the cruise at 60 and that is how it was broke in. the most important thing i think is to seat the rings and that is accomplished by working (or lugging the engine) which is not the same as going fast.

 

[Akmechanic]

the most important thing i think is to seat the rings and that is accomplished by working (or lugging the engine) which is not the same as going fast.

Totally agree. The rings need worked to seal properly to perform right. Trouble is, during this break-in period, the rings are producing more heat...so higher RPMs to wear them in and lower to cool them off a bit is the theory. (letting off the throttle let's a small breath of air in without as much combustion going on)
The old oil for break in was an uncompouned oil that didn't have the cleaning agents that newer oil has in it. With the older style, the break-in period was shorter but it left deposits in the engine too. The new oil is formulated to do it all nicely, along with advancements in the metallurgy since the 60s and 70s. Maybe all of my near useless info was good afterall... My students don't listen so I hope someone did.

 

[blueoval9erlifer]

thanks for the info AK that must be why some of the old school mechanics use a standard no additive 30 weight oil for about 200 to 300 miles for break in and then change the oil and filter to what is "supposed to be used" in the engine

 

[kert0307]

Good info, thanks for that. I will do this for peace of mind when I take my trip.

Yeah, not much to see in Iowa. It's pretty flat and mostly all farmland, born and raised here.

Why not just take the hwys and stay off I35 or I80. You'll have to slow down every 15 miles or so for all the small towns you will go through.

 

[boss377]

There's no correct answer to this question. Just take it easy for a few hundred miles and avoid running the s+#t out of it for a thousand miles. That's it; end of story.
I went with a 7,500 mile change so I'll be in line with the service interval Ford's maintenance plan uses. I do pay a little extra and use Mobil 1.
I use Blackstone Labs for analysis and my numbers are always perfect.
There's no benefit in changing oil early; these cars are equipped with an oil filter! There is no way to prove otherwise.
The bottom line is that you are going to do what you want to do anyway, and that will be just fine.
Just my 2-cents.

 

[Rick]

Umm... if oil wasn't getting there already, wouldn't a typical highway trip destroy the engine? sorry, I'm not trying to be a knob, it just doesn't make sense to me.

Normally you want and need VERY little oil in the top of the cylinders. Too much and you will burn oil and blow smoke. The piston rings limit how much oil gets to the top of the cylinders. When you have good valve guides, which a brand new engine does, the only oil that gets to the top end is the oil that gets past the piston rings.

By decelerating you are helping to move oil to the top end during the critical break in period. Running the engine steady won't accomplish that.

Hope that makes sense.

BTW, for my own new engine break in regimen I always change the oil and filter at 500 miles to get rid of any metal from the manufacturing process and the metal which is initially shaved off the high spots on your cylinder walls, piston rings etc. After the 500 miles I change as recommended by the manufacturer.

I bought my '93 Explorer brand new. I used Mobil 1 since my 500 mile change and the engine still runs like a top. The only work done to the engine in the past 20 years was a valve job. Valve seats are lubricated by the fuel, not from engine oil. When I pulled the heads off the engine, the cylinders looked beautiful with hone marks still present. Not a bit of sludge or varnish anywhere.

 

[VinceL]

Thanks for the explanation Rick. This place is awesome for learning stuff...

 

[incredibleman]

Interesting. I bought a new Suzuki motorcycle a few years ago and I broke it in with a lot of big throttle at low revs, and a lot of engine braking. No idea what the verdict is. It runs great and has great heaping gobs of power, but any 1000cc sportbike with 10,000 miles is going to run great and have gobs of power anyway. I also did the first oil change at 1000km, and I expected to see some metallic flakes in the oil, but there was absolutely nothing detectable, looked like brand new oil (but a bit darker). Even the magnetic drain plug, it was perfectly clean. I don't imagine my new Ranger engine is built with the same sort of precise tolerances, but I'm not sure whether to do an early oil change. The dealer told me to do the first one at 5000 miles.

 

[kert0307]

I also did the first oil change at 1000km, and I expected to see some metallic flakes in the oil, but there was absolutely nothing detectable, looked like brand new oil (but a bit darker). Even the magnetic drain plug, it was perfectly clean.

I bet most if the wear parts in that motor are non magnetic anyway...

 

[dolph2709]

3.5L ecoboost break-in

During break-in period (for 3.5L ecoboost engine) does it make any difference to use Premium gas vs Regular?

 

[peterk9]

from the owners manual;

Isn't amazing what you can find in the Owner's Guide?

Peter

 

[peterk9]

During break-in period (for 3.5L ecoboost engine) does it make any difference to use Premium gas vs Regular?

I wouldn't think so. Premium gas just gives you some added performance but should not affect the engine break-in as long as you follow the Owner's Guide scenario for the new engine. Just my guess though.

Peter

 

[77rednecktruck]

I think break in is a myth. I have built a few motors over the years and bought new cars, I just drive them normally and do not have issues. My Jeep with the Hemi I bought a few years ago went on a trip the first week I had it pulling a 3000 lb. trailer.