1004ron

OK, that's good. How about the second part of the question?

Just revisiting this - fairly risky to drain the coolant with it at normal operating temperature and even if that was done, it would be well below operating temperature with the new cold coolant just added and would take longer than 10 minutes to get back up to operating temperature.

I have done two drain-fills on my 2017 Sport. The fact that the new spec Ford coolant is compatible with the old spec there's no issue with not purging all the old coolant and I didn't purge the system on each occasion - the first time it the fluid in the reservoir didn't look anything like the new color, and with the second drain-fill its closer to the new color. Maybe next time I'll purge it with distilled water before refilling.

Not sure who that comment was directed at? I always buy the concentrate and mix it 50/50 and the product details state clearly not to go higher than 60/40. My comment was to drain/fill a few times with distilled water and that way you would have removed about all of the old coolant mix, then go back with say a 60/40 mix knowing that the engine still contains some straight distilled water. I use a vacuum fill kit similar to this.

"Must have been RockAuto." - That doesn't sound like a confident response to me. Reliable code reading is the best starting point. .

The only way to get only the new coolant in the system is to do a few drain-fills with distilled water and then the final fill with a higher concentration of the new coolant expecting some distilled water to remain in the engine.

Welcome. I'm not surprised to hear that you have Fords in Canada - afterall they build them there

Running the coolant flush for only 10 mins would not have warmed up enough to open the thermostat and you should set the cabin heating to MAX for it to circulate through it.

The PCM theory is an even deeper rabbit hole vs the unknown condition of the spark plugs and coils. 2 rounds of plugs and coils of uncertain origin and quality = 2 rounds of uncertainty. Not having a reliable code reader is the reason why your diagnostics is floundering leaving you to guess and assume. Use the free app Forscan Lite which will work with many but not all OBDII adapters, even many of the cheap OBDII adapters. Amazon.com: vgate vLinker FD Plus OBD2 Adapter Bluetooth BLE Scanner for FORScan, Work with iPhone, Android, and Windows : Automotive

Welcome. What alternator did you purchase and from where did you purchase it?

I don't have an explanation for what you're experiencing but can confirm that none of the changes I've made using Forscan have reversed themselves.

If you're unsure of where the plugs were purchased then they're suspect in my opinion and would recommend they're replaced using ones bought from a reliable supplier such as RockAuto, and not eBay or Amazon. The knockoffs also come in Motorcraft boxes.

Welcome. Best get a multimeter and measure the voltage at the battery when you attempt a start. Also scan it for stored fault codes.

What a coincidence - this morning as I pulled off my driveway onto the road I got a Tire Pressure warning - pulled back into my garage and found a nail embedded in the rear tire. Switched to my Edge for the drive to work and will repair the bike tire when I get home.

Like these OEM plugs? Set of 6 OEM Motorcraft SP594 Ford CYFS12YRT3 Spark Plugs Replaces SP542 SP578