species8472

2017 3.5L EB with 21B10 done. It's garage kept with coldest at around 5C/40F despite -30C/-22F outside here in Edmonton, Alberta, Canada.

Now a couple weeks ago and for the first time, I had to leave it outside overnight at -20C/-4F. When I started her in the morning, she got the infamous cold start phaser rattle for the very first time.

But here's the twist, since then I have parked it back inside the garage. And I have not had the cold start rattle again even after letting it sit for 3 days straight.

So, the question is - should I get the phaser replaced?

b-real

iTrader: (1)

Are you still within warranty?

SIC_HDPP

Do you have a warranty with ford? Try leaving it outside again and see if it occurs. If both are yes I would get them replaced.

kfergiez

Yep. The trick is repeating the issue.

The failure point of the cam phaser is a locking pin in the phaser itself. When you start your engine, oil pressure goes to the phaser to operate the phaser. The LACK of oil pressure at the start when that pin is not engaged is what causes the rattling.

The fact that you parked it in an extremely cold environment and it started rattling then tells me that your pin never engaged at shutdown... my SPECULATION is that it will get worse. But you've got to repeat it.

species8472

Yes, still under original 100,000 km powertrain warranty. Plus whatever the 21B10 extension.

The problem is repeating the rattle, it hasn't rattled at all since that one time overnight at -20C/-4F. It's only -7C/19F this week overnight but I am going to leave it outside and see.

b-real

iTrader: (1)

Not sure it’s phasers. “Cold start” doesn’t mean the engine has to be at 0F, just not up to operating temp. When my phasers would rattle it was in the summer, so maybe 60F overnight. And it would do it every “cold start”.

Regardless, if you have a powertrain issue you should get it resolved while it’s on Fords dime, but whatever the issue is the dealer will have to verify what the issue is before they can fix it with having Ford pay for it, which means leaving it with them for some amount of time.

kfergiez

Absolutely true. My thought was that the retention pin never parked... But I may jumped the gun on that.

OP let us know!

species8472

Dang it. Left her outside overnight and no rattle on start up this morning. I can't reproduce it so I probably can't get the dealer to do anything.

Now I am wondering if the extreme cold a few weeks ago was causing the pin not to lock as a one time thing!?!?

YEGdude

Could be just the start of pin wear.

How many KMs do you have ?

species8472

94,000 km