Is New Engine Break In Procedure Still Necessary?

[Fairweatherider]

Do today’s new engines still need a “break-in” procedure? Or just drive it normally and do the first one or two oil changes early?
I’m interested in what the GM owner manual suggests and also what real world engine builders/mechanics think.
I’ve read some guys say that “taking it easy” for the first 500 miles just glazes the cylinders and doesn’t let the rings wear in properly or fast enough. The theory is that you should drive it hard and vary the RPMs right from the start (after reaching full operating temperature of course).
What do you all think? Is new engine break-in a thing of the past?

 

[Joseph Garcia]

This is a good question, but unfortunately, I do not have the answer.

The last new vehicle that I had was a 2015 Honda, and I changed the oil early, based on traditional engine break-in theory. I was reprimanded by the dealer for the early oil change, stating that the first batch of oil in the engine was a special break-in blend of oil that was designed to go the full mileage until the first oil change.

Let's see what other folks have to say here.

 

[Marky Dissod]

Do today’s new engines still need a “break-in” procedure? Or just drive it normally and do the first one or two oil changes early?
I’m interested in what the GM owner manual suggests and also what real world engine builders/mechanics think.
I’ve read some guys say that “taking it easy” for the first 500 miles just glazes the cylinders and doesn’t let the rings wear in properly or fast enough.
The theory is that you should drive it hard and vary the RpMs right from the start (after reaching full operating temperature of course).
What do you all think? Is new engine break-in a thing of the past?

I'd be willing to bet lots of money that I don't have, that GM does not bother with 'break-in' motor oil,
they just use a Mobil1 factory fill that anyone could find at any auto parts store.

If that's the case, then, simply because I'm an overcautious pessimist,
I'd look up the break in procedure for GM's LT4, and use that.

Actually, if it has Engine Confusion (DFM), I'd entirely avoid this feature and drive in L9 during the break-in.
Soon as you can find a DFM disabler (or even a minimizer), I'd install it pronto.

Don't forget to change the ATF & differential fluids after their break-ins as well.
It's an opportunity to find and use other upgraded fluids that would still be warranty-approved.

Do your very best not to drive at any engine RpM or road speed 'constants'.
The more variable you drive it, the better the break-in. Push it, but don't shove it - be sensibly aggressive.
I'd keep it under 4750RpM til after the 1st oil change.

 

[jfoj]

Best thing you can do is do not take short 15 minute trips, depending on the outside ambient temp the engine oil in these engines can take up to 30 minutes to match the engine temperature.

Even a 4-8 mile vehicle will have fuel in the oil. Pull the dipstick and check and smell for yourself.

I would try to get the vehicle on the highway for a 45 minute drive to fully warm the engine oil.

If you are getting a 6.2l run Premium fuel in it.

Thing to consider

 

[Fairweatherider]

And if I do smell oil on the dipstick, should I drive it to burn the fuel out of the oil, or should I stop and do an oil change? I understand that this is a DI engine, and that fuel in the oil is a side effect of excessive idle time. I've never owned a DI engine, so I don't know anything more than that.

 

[PPK_]

Do today’s new engines still need a “break-in” procedure? Or just drive it normally and do the first one or two oil changes early?
I’m interested in what the GM owner manual suggests and also what real world engine builders/mechanics think.
I’ve read some guys say that “taking it easy” for the first 500 miles just glazes the cylinders and doesn’t let the rings wear in properly or fast enough. The theory is that you should drive it hard and vary the RPMs right from the start (after reaching full operating temperature of course).
What do you all think? Is new engine break-in a thing of the past?

I recommend changing oil and filter at 25 hrs or so on the engine. You can see what drained out on my first oil change at 25 hrs… nothing better than a pic to look at.. zoom up on it and you can what came out…

 

[Marky Dissod]

[Rant]
How hard would it be for GM to break in each engine before installation?
Thanks for nothing.
[Rant over]

 

[Vladimir2306]

Judging by the engines that come straight out of the box from GM, I get the feeling that GM has stopped even doing cold running-in. So, running-in is vital, and after it, you should change the oil, somewhere around the first 1000 miles.

 

[jfoj]

@Fairweatherider

Fuel contamination can be managed, however, it can also become cumulative depending on the weather and driving conditions.

Best way to manage the problem is make sure you are driving regularly 30+ minutes straight and/or get on the highway for 30+ minutes, probably at least once a week.

Short 10-15 minute trips, regularly using using the Remote Start feature or starting the engine and allowing the engine to warm up without driving either in the Winter or Summer clearly puts more fuel in the engine oil. I believe the Auto Stop/Start feature will also contribute to more fuel in the oil as well. Excessive idle time can also be a contributor to fuel contamination as well due to idle being a richer mixture when compared to cruise mixture.

If you are running 5W30 or 0W40 oil you also have at least a bit of safety margin for fuel contamination in the crankcase as well. As fuel contaminates the engine oil its viscosity is lowered.

As always, manually check the engine oil every 2nd to 3rd fuel fill up for proper level and also smell the oil for traces of fuel. Once you get your nose trained for fuel detection, you will be in a better place to understand how your driving habits may contribute to fuel contamination in the engine oil.

 

[jfoj]

Back to the original question about break in oil, from initial oil analysis it appears that the factory fill has a higher level of Moly in the oil. Unclear if this is due to Moly coatings on the camshaft or bearings, Moly assembly lube or an oil with Moly additives. Moly is a good friction proofing/lube additive.

Personally is you plan on running something other than 0W20 engine oil, I would change the oil ASAP. Even if you plan on running 0W20 oil, I would change the oil by 10 hours or before 500 miles. Get a magnetic oil drain plug, search my user name as I have a thread on this.

There is a good oil on the market that has a high Moly content, but it is not officially Dexos approved, but pretty much meets the Dexos requirements. There are licensing issues and oil formulations need to be provided to GM for Dexos approval and some vendors do not want to provide the oil formulation details to protect their products. If anyone is interested in more info, PM me for details.

And about the engines being "Cold Tested", I am pretty sure this is not being skipped, "Cold Testing" shows no level of combustion because no fuel is introduced into the engine. There would be no real benefit for skipping "Cold Testing" because this limits feedback for problems during quality control.

Most modern engines need less "Break In" period, especially with piston rings. Gone are the days of harder piston ring materials and todays engines have matched cylinder hone surface to seat softer piston ring materials in a quicker fashion. Same with camshaft and lifters now that roller lifters are more the standard. Break in has more to do with bearings, transmissions and differentials, not putting undue loading on these components for 500-1000 miles or so. Most normal driving will be fine for the first 500-1000 miles, whether you are in town or on the highway. Refrain from towing and hauling heavier loads would be wise as well.

 

[Silverado4x4]

I don't believe at all on the letting the engine idle or using remote start is putting more fuel in the engine vs normal driving and getting in the oil. The metered injectors are putting enough fuel in the cylinder needed for combustion and more fuel for higher rpm's so way less fuel at idle that is burned off when combustion is happening. So what is being said here is fuel at idle is washing down the cylinder and draining down to the oil. No way. Only way is if the engine rings are worn and your getting blow by then gas will get in the oil or you have a leaking injector dripping fuel in the cylinder when the motor is not running.

 

[jfoj]

@Silverado4x4

Believe what you want. DI engines are a much different animal than previous port injected engines. The higher pressure fuel delivery with DI, especially when the engine is cold will leave liquid drops of fuel in the cylinders especially around the piston rings, liquid fuel does not burn, so it will work its way quicking into the crankcase.

Additional you need to understand the engine coolant temperature and oil warm up behavior of an engine that is just idling from cold start vs driving. See graph below. Cold Start Idle was for 15 minutes, Drive was 17 minutes. Even at 17 minutes of driving the engine oil was only around 175F even though the engine had hit 200F. This was semi rural driving with at best maybe 4 traffic lights and speeds typically between 35-45 MPH. The engine was not even 100% fully warmed up at 17 minutes of driving, usually these engines operate between 203-210F when fully warmed up. Ambient temperatures due influence warm up times, but we are still not out of the Winter temps in many areas. Many owners tend to use the Remote Start features more when the temperatures are colder to warm the cabin and clear the windows, I get it, sometimes you need to to this, but doing this on a regular/daily or multiple times a day basis is not a wise idea.

It also not all about the engine idle time as well, it is about getting the oil, not the engine, up to a high enough temperature to start to "cook" fuel out of the oil. Again, fuel contamination of the oil can be cumulative depending on the outside ambient temperature and how the vehicle is driven. The more short drives, the worse the problem gets.

Pull your dipstic, check the oil level and smell te towel used to wipe the dipstick for fuel. A number of reports about vehicles fresh off the dealer lot have fuel smell in the oil.

 

[blanchard7684]

yes I think there is reason to alter driving habits with a new engine, even with modern engines. I would opt to drive it such that the rings will get a good wear pattern. This would be something like stop and go driving and/or varying rpm slightly for a few hundred miles. It doesn't have to be perfect. You won't trash your motor if you don't do this to perfection. The reality is that before you signed the papers 4 other people drove your car and likely floored it repeatedly. lol.

And the DI engine's propensity to put fuel into the oil, I recommend the first oil change quite early as well. I did mine at 1800 miles.

I had a 4runner that I bought off the lot and went on an off roading trip. I literally left with gear from dealer lot. Lots of highway miles and heavy acceleration to pass. High altitudes where the anemic 4runner engine stayed at 4.5K for minutes on end to keep 78 mph. No issues and a total violation of the owners manual break in procedure.

 

[WalleyeMikeIII]

The owners manual describes the GM proscribed break in process, which is essentially not much.
Don't use cruise or drive at constant speed/rpm for the first 500 mi
Be gentle on brakes while the pads and rotors seat to each other
Don't tow for firt 500 miles.

Past that I would try to do a few full thermal cycles of getting the engine to full operating temp, then letting it cool all the way back down (which you will probably do anyway in 500 miles).
And maybe somewhere past 350 miles, give it a few higher RPM runs (but not Wide Open Throttle) to around 3500-4000 RPM.

 

[Marky Dissod]

View attachment 451849

For the first 322 km (200 mi):
• To break in new tires, drive at moderate speeds and avoid hard cornering.
•* New brake linings also need a break-in period. Avoid making hard stops. *This is recommended every time brake linings are replaced.

For the first 800 km (500 mi):
• Avoid full throttle starts and abrupt stops.
• Do not exceed 4000 rpm.
• Avoid driving at any one constant speed, fast or slow, including the use of cruise control.
• Avoid downshifting to brake or slow the vehicle when the engine speed will exceed 4000 rpm.
•* Do not let the engine labor. Never lug the engine. *This rule applies at all times, not just during the break-in period.

For the first 2 414 km (1,500 mi):
• Do not participate in track events, sport driving schools, or similar activities.
• Check engine oil with every refueling, and add if necessary. Oil and fuel consumption may be higher than normal.

Pity that break-in procedures do not include disabling Engine Confusion / DFM.

 

[RET423]

No, drive it exactly like you drive whatever else you drive; engine break in is an enduring wives tale

If it's a rebuilt do the first oil change early, other than that let it eat

 

[Mollys70]

I think if GM wanted a break in period, they would have programmed that into the computer.

 

[djnice]

GM wrote the owners manual posted above. That's what they recommend. How could they program the computer to randomly change speeds while the owner is driving down the highway.

 

[West 1]

Modern pistons rings seat quickly but only when under a load. A new engine will create more heat than a fully broken in engine so watch temperatures closely and never let it overheat.
If you have a long hill to use that is perfect for engine break in, if you are using 50% or more throttle to climb the hill the combustion pressure will help the rings seat in perfectly.

When started on an engine dyne modern rings will seat by the end of the first dyno pull. A dyno pull lasts maybe 30 seconds start to finish but those are done under full throttle and put full combustion pressure on the rings to help them seat quickly.

After the first 50 miles RPM is not a concern but heat will be for the first 1,000 miles. This all pertains to Gasoline engines.

Dielsel engines need to be loaded to seat the rings but it takes more load to do it on diesel engines. It is recommended to pull a trailer to help load the engine so the turbo's reach full boost and help break in the new rings.
On Class 8 Trucks, the big rigs, 18 wheelers, they are designed to haul 80,000 pounds and break in procedure recommends they hook up to an 80,000 pound load and hit the road to break in the rings. If they don't the engines use a lot of oil.

This is recommended to seat the piston rings so you get good combustion sealing and less blow by. Obviously if you see temperatures climbing while doing this shut it down and let it cool. High Temps can destroy your new engine quickly.

These notes are just addressing breaking in the piston rings. The rest of the car will need some pampering also to break in properly so read the manual for details.

 

[Sean Michael]

I think if GM wanted a break in period, they would have programmed that into the computer.

I bought a new Cadillac CT5-V and the digital guage cluster shows a reduced redline for the first 500 miles, there's video on the Cadillac forum of someone hitting 500 miles on the odometer when the redline immediately jumps up to normal. So GM can and does implement some programed break-in protocol when they deem necessary. I'm assuming GM would've done the same on other vehicles like Tahoes and Yukons if they thought it was import enough.