7.3 Engine break in
More Turbo
Joined: Mar 2021
Posts: 507
Likes: 233
I have always broken in my vehicles by putting on the first 1,000 to 1,500 miles by driving easy, varying the RPM, keeping it below half throttle and 2,500 - 3,000 RPM. Then I change the oil and drive it a little more normal for a bit. Then off to the races. My biggest complaint is owning an oil burner. No car I have followed this procedure for has been an oil burner. Then again, several used cars I have owned haven't been either and probably weren't broken in like this. But I will continue doing this for every new car I buy. Can't hurt and might actually help.
Hotshot
Joined: Jun 2003
Posts: 12,353
Likes: 4,388
From: SW VA
I drive a new engine more spirited than normal, making sure to use more engine braking, and more RPM range. It’s habit for me, as this is encouraged for motorcycles and ATV’s to help seat the rings.
I do this for 1k to 1500 miles and then change the oil. New engines produce more wear particles as the bearings and machine surfaces form their initial wear patterns. Sand from casting could also be hiding in some tight corners of the block. A cheap oil change is good peace of mind, and sure as hell won’t hurt anything.
I do this for 1k to 1500 miles and then change the oil. New engines produce more wear particles as the bearings and machine surfaces form their initial wear patterns. Sand from casting could also be hiding in some tight corners of the block. A cheap oil change is good peace of mind, and sure as hell won’t hurt anything.
More Turbo
Joined: Oct 2023
Posts: 700
Likes: 478
I mean we could just settle this if someone is willing to buy two identical trucks and break one in the way the manual suggests and just drive the other one normally, then at say 5,000mi pull both engines and dismantle to inspect and compare wear markings on all effected parts. Who's up for it?
Hotshot
Joined: Jun 2003
Posts: 12,353
Likes: 4,388
From: SW VA
I mean we could just settle this if someone is willing to buy two identical trucks and break one in the way the manual suggests and just drive the other one normally, then at say 5,000mi pull both engines and dismantle to inspect and compare wear markings on all effected parts. Who's up for it?
How one person treats their engine/transmission, can be similar to, or polar opposites of how they treat their paint. Some people spend thousands of dollars on paint correction, buffing, ceramic coatings, etc...and others don't do anything and might wash their truck once every few months. Some people do maintenance/fluid changes early, and others just let the truck tell them when to do it.
I think as long as the maintenance is getting done at or before the manufacturer's maintenance schedule, the truck will be just fine for a long time to come.
7th Gear
Joined: Feb 2018
Posts: 7
Likes: 1
When I worked at an ag dealership, the only recommended break in on tractors was to change front diff and planetary oil. It's the only unfiltered oil on the tractor. My plan is to drop rear diff oil before service interval and vary engine speed with only moderate load.
Back in the SBC days we would keep rpm above 2k to prevent excessive cam wear on a new build. Less wear at higher rpm than idle.
Was also always told rings won't seat with synthetic oil either, but better machining, and they are filled with synthetic oil from new disproves that.
This is my build week for my first new vehicle and I'm getting excited.
Back in the SBC days we would keep rpm above 2k to prevent excessive cam wear on a new build. Less wear at higher rpm than idle.
Was also always told rings won't seat with synthetic oil either, but better machining, and they are filled with synthetic oil from new disproves that.
This is my build week for my first new vehicle and I'm getting excited.
Hotshot
Joined: Oct 2006
Posts: 10,173
Likes: 8,041
From: Texas
When I worked at an ag dealership, the only recommended break in on tractors was to change front diff and planetary oil. It's the only unfiltered oil on the tractor. My plan is to drop rear diff oil before service interval and vary engine speed with only moderate load.
Back in the SBC days we would keep rpm above 2k to prevent excessive cam wear on a new build. Less wear at higher rpm than idle.
Was also always told rings won't seat with synthetic oil either, but better machining, and they are filled with synthetic oil from new disproves that.
This is my build week for my first new vehicle and I'm getting excited.
Back in the SBC days we would keep rpm above 2k to prevent excessive cam wear on a new build. Less wear at higher rpm than idle.
Was also always told rings won't seat with synthetic oil either, but better machining, and they are filled with synthetic oil from new disproves that.
This is my build week for my first new vehicle and I'm getting excited.
The last three new trucks I have purchased have all been duallies. Of those three, two had to go to work the day after the purchase pulling either an 18000 lb fifth wheel or an 18000 lb gooseneck. Third one had an easy life for the first couple thousand miles. Now, take a wild guess as to which one needed the rear differential completely rebuilt before the 36000 mile bumper to bumper warranty went bye bye!
If a person needs the truck to work; there is no sense obsessing about how soon. Put it to work and don’t look back. If it’s gonna break, break it on Fords dime, not your own!
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Cargo Master
Joined: Jan 2004
Posts: 2,429
Likes: 701
From: Minnesota
Why is everyone so focused on the engine? IMO, it is the differentials that need the break-in. Do a coasting test somewhere where it is safe to do so. You will be amazed at how much better your truck coasts after 1,000 miles compared to 0 miles. Those differentials are tight when new.
After our original 7.3 failed during a towing vacation, we towed our 5er with the brand new replacement engine; zero miles on the engine. It has been fine. No ill effects. But, the differentials were already broken in; so no concerns.
After our original 7.3 failed during a towing vacation, we towed our 5er with the brand new replacement engine; zero miles on the engine. It has been fine. No ill effects. But, the differentials were already broken in; so no concerns.
Mountain Pass
Joined: Feb 2024
Posts: 168
Likes: 153
As for my new 7.3, having been a mechanic for a couple decades, I changed it around 700 miles. I believe the best information on this subject is in this video:
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