HELP! Will 5w30 Full Synthetic Prevent Proper Break-In?

[Albertcado]

I just got my car back with a new short block under warranty from the dealership,
but the tech put 5w30 Full Synthetic in the new engine because I simply asked if that is something Ford would approve. Basically throughout the warranty process I asked him about it and without a heads up or asking (he didn't ask Ford either if that was okay for the new engine) he just went ahead and used 5w30 FS and I ate the cost of the oil. He assures me it will still break in properly and I won't have to worry about the rings not seating properly since the difference in factory oil and the 5w30 FS is not huge. I was planning on switching over to 5w30 Full Synth on my 1st oil change on the new engine anyways, but obviously propery break-in is the biggest concern.

Do you guys think it will be okay or is this a huge concern? The tech (who is very competent, he is the only one who works on engines at my reputable dealership and has a lot of experience with mustang engine work, short block, long block replacement, etc.) tells me to drive it easy for the 1st 500-1000 miles and get an oil change in 5000. Should I go back and have them do the oil change now to 5w20 blend while it has very low miles on it to be safe or will the car still be able to break-in properly on the 5w30 Full Synth?

*side note, 1st engine was broken in properly with the factory oil (5w20 blend) and 1st oil change was done around 3k miles. This engine eventually had bad enough scoring to cause oil consumption and oil burning in cylinders, which Ford immediately approved for this 2nd short block so...

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[Ock]

im intrested to find out...

 

[Albertcado]

im intrested to find out...

I'm thinking it's kind of pointless to switch to the 5w20 blend now even with the low miles since the car was test driven on the 5w30 FS and I drove it home yesterday and commuted to work today, or maybe it is still better to have to switch the oil out now while its early. Is there anyone at Ford I can ask about this?

 

[Ock]

I'm thinking it's kind of pointless to switch to the 5w20 blend now even with the low miles since the car was test driven on the 5w30 FS and I drove it home yesterday and commuted to work today, or maybe it is still better to have to switch the oil out now while its early. Is there anyone at Ford I can ask about this?

im gonna go by what dealer puts on the ticket, so if any issues its on them. i know ive been thru to much at this point to worry about oil... lol i bet you have to.

 

[Albertcado]

You think so? It should still break in properly with the 5w30 full synthetic right?
Seems ridiculous that the 5w30 FS vs 5w20 blend in a new engine will be the deciding factor in the rings not seating properly. I'm really hoping I have zero to little oil consumption on this new engine, the 1st one was consuming lots which got me here in the first place...

 

[GregO]

@Albertcado
https://www.mullenixracingengines.com/how-to-break-in-your-engine

Read this link and discuss this with your Ford Motor Tech.
Don’t jeopardize your new short block warranty.
I’d suggest a candid conversation with the Dealer on Fords guidelines for the VooDoo 5.2 break-in procedure as that and your Gen3 use coated cylinders and Ford has a supplemental procedure for proper ring break-in.
Yes the VooDoo uses lower tension rings vs. the Gen3 but there is merit to an oil being too good and wrecking the burnishing process.

 

[Albertcado]

what oil weight did you start running on your 1st change?
I'm assuming you have very little to no oil consumption then?

 

[Albertcado]

hrm.. so maybe it's not a bad thing that my rebuilt engine started off with 5w30 FULL SYNTHETIC...

 

[WildHorse]

Brad Penn break in oil if you wanna be super anal about it.

 

[GreenS550]

You will be completely fine. Ford uses 5W30 from the factory on 21 and up GTs and the engine specs are identical.
Break in oil has been used by many of us that rebuild engines but a new shortblock is going to be identical to a new GT engine less the heads.
No worries at all.

 

[GregO]

hrm.. so maybe it's not a bad thing that my rebuilt engine started off with 5w30 FULL SYNTHETIC...

It’s good they used 5W-xx oil but Full Synthetic has obviously caused you some anxiety and rightfully so. The Gen3 coated aluminum cylinders need special care prevent glazing over and stopping rings for seating that last 15% to 20%
Talk to your dealer so you don’t end up voiding the warranty.
No one but the factory knows exactly what oil is installed at the motor assembly line during final fire up before heading off to Flat Rock.

@Albertcado
This is about the only 5W-XX break in oil I know of. The Coyote bearing-less overhead cams need instant oil delivery so only 0W-xx or 5W-xx should be used.
https://drivenracingoil.com/i-30497749-br-30-5w-30-conventional-break-in-oil.html
Even conventional Castrol GTX or Pennzoil 5W-30 for the first 1000 mile or so will do the trick.

 

[Albertcado]

It’s good they used 5W-xx oil but Full Synthetic has obviously caused you some anxiety and rightfully so. The Gen3 coated aluminum cylinders need special care prevent glazing over and stopping rings for seating that last 15% to 20%
Talk to your dealer so you don’t end up voiding the warranty.
No one but the factory knows exactly what oil is installed at the motor assembly line during final fire up before heading off to Flat Rock.

@Albertcado
This is about the only 5W-XX break in oil I know of. The Coyote bearing-less overhead cams need instant oil delivery so only 0W-xx or 5W-xx should be used.
https://drivenracingoil.com/i-30497749-br-30-5w-30-conventional-break-in-oil.html
Even conventional Castrol GTX or Pennzoil 5W-30 for the first 1000 mile or so will do the trick.

I talked to my tech again and he's confident the 5w30 full synthetic will have no negative effects on proper break in or rings seating on my new engine. I'm going to roll with it, break it in, then drive it hard after 1k miles. Seems ridiculous to flush 10qts of brand new 5w30 Full Synth oil just to put in 5w20 blend for "proper break-in", I feel like a switch over now on the new block would probably do more harm than good. My 1st engine that this one replaced went through factory oil and proper break in and look where it got me.

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