Hello everyone. I have a 2019 F150 with the 2.7 EB that I bought new. It is approx 24K miles. When I take off sometimes after the auto start/stop there is a grinding and humming sound that starts. The faster it accelerates the louder is gets. Sometimes it happens for just a second or 2 but somethings it is a couple minutes before it is goes away. It happens about half the time the truck auto cycles. I never lose power during. When I deactivate the auto start/stop before it shuts off there is no issue. My truck is still under factory warranty and was thinking about taking it in before it expires. Any ideas on what this may be?

 

Wonder if the starter is disenguaging clearly after a "auto start" event.

I know they say the starters are built for AS/S, but I don't trust it long term, so I bought an "Auto Start / Stop Eliminator" for our one vehicle that has the deal, a '19 Forester. I also do not like sitting at a highway entrance from a side road or gas station, waiting to pull into traffic, with a dead engine. It was $100 well spent in my view.

 

Double posts get difficult to follow.

Please try not creating multiple posts in different areas of the forum in the future.

 

Combined them here.

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Do you have 4WD? Manifold vacuum is lost when the engine stops. Do you see where I'm taking this? Where is the grinding heard from?

 

Yep -I was staying away from this one. I think I am IWE'd out.

 

just a theory bases on your description of the grinding you hear after taking back off. I see it as a possibility that you're losing some vacuum to the IWE until it can build back up. Check valve perhaps but just a theory. Drive in 4WD for a while and see if the grinding goes away after an Auto stop.

 

So I thought about it for at least 5 seconds -I suspect the system would not vent the IWE system during auto stop, and as long as the check valve is working properly, IWE should remain unlocked.

Before we theorize further, maybe we should wait for OP to update!. haha we're already going down that rabbit hole.