2018 MAX Limited Engine/Turbo Stutter on Hard Acceleration. Turbo Issue?

[Bmanxx13]

Hi all,

My wife and I bought our 2018 MAX a couple months ago and absolutely love the vehicle. Perfect for our family, and has much more room compared to the Explorer.

This weekend we decided to take a family trip up to the mountains and I noticed while on an 6% grade incline (most of the drive up, and some back down) the turbos felt like they were sort of ...giving out. I would constantly see the boost gauge bounce from 0 to ~15+ until I let off the throttle, and as soon as I got back on the accelerator the boost would start bouncing again. I could feel less performance while this was happening. Most of the way we were going ~80 MPH. I was able to maintain speed, but this experience was new to me.

Is this normal behavior with the EcoBoost engine? This was our first trip up the mountains with the EcoBoost engine so I'm not sure if this is normal or not. We haven't noticed any odd behavior with the engine on the highway, nor in city driving. No hard idle, and no engine lights.

I googled around and saw many posts about turbo stuttering caused by the CAC (charged air cooler) and moisture buildup, but wasn't sure if this affects 18+ models. Any ideas?

 

[Expy lover]

This issue not normal.


Sent from my iPhone using Tapatalk

 

[Dice Roll]

I saw a flutter today for the first time in my 19. I didn’t sense anything in how it performed. Just saw the gauge flutter going up a hill. I put the boost up there first thing, and have been watching it. Just finished my first week with the truck.

 

[Squark]

Did it feel like stuttering or was it smooth and your rate of acceleration was changing? I had a bad ignition coil and discovered it in the mountains. Whenever I'd give it a lot of throttle it would shudder and stumble, but idled perfectly and was fine in normal driving. I eventually got a check engine light and the dealer replaced the coil.

 

[Bmanxx13]

It only happened under heavy acceleration. Definitely felt like the truck was hesitating, and at times lack of power. As mentioned, when I let go of the throttle then accelerated it would be fine for a couple seconds then go back to stumbling up the steep inclines. It wasn’t enough to alarm my wife or kids, but I could feel that something wasn’t right immediately. I thought the truck was going to stall the first time I experienced it, but kept going.

I haven’t had a check engine light pop up yet, but I’ll have the dealership check the coils and plugs. Hopefully they can find something to fix the issue... I’ve read that there can be error codes even without the check light coming on. Ours also idles and drives perfectly around the city and on the highway. Most of the time it’s hard to tell if the truck is on.

 

[Squark]

It only happened under heavy acceleration. Definitely felt like the truck was hesitating, and at times lack of power. As mentioned, when I let go of the throttle then accelerated it would be fine for a couple seconds then go back to stumbling up the steep inclines. It wasn’t enough to alarm my wife or kids, but I could feel that something wasn’t right immediately. I thought the truck was going to stall the first time I experienced it, but kept going.

I haven’t had a check engine light pop up yet, but I’ll have the dealership check the coils and plugs. Hopefully they can find something to fix the issue... I’ve read that there can be error codes even without the check light coming on. Ours also idles and drives perfectly around the city and on the highway. Most of the time it’s hard to tell if the truck is on.

That sounds like what I experienced. It only stumbled up steep inclines or under heavy throttle. It's possible you have a pending code that hasn't tripped the check engine light yet.

 

[Bmanxx13]

I saw a flutter today for the first time in my 19. I didn’t sense anything in how it performed. Just saw the gauge flutter going up a hill. I put the boost up there first thing, and have been watching it. Just finished my first week with the truck.

Yeah, going up hills doesn't really affect mine as much that I've noticed. The issue came apparent once I was on a steep incline under continuous heavy throttle on our way up the mountains. It would probably also happen when towing, but we haven't towed with our Expy yet, so I don't know for sure.

 

[Dice Roll]

How much boost do you guys see normally? Mine shows zero or close to it most of the time. Gradual acceleration doesn’t seem to move it much or at all. I barely hear the whistle when it does show some boost. I’ve had a powerstroke for years and I’m used to hearing the whistle a lot more.

 

[AKentPhoto]

Uneducated guess is wastegate actuator... Older EBs did it to the point where you could hear them clanking on cold start. Open the hood and see if you hear any clanking when you cold start. It will be coming from the turbo itself.

The wastegate is what regulates the amount of boost.

 

[Mike Wolfe]

Were you using 87 octane "CRAP" fuel
If so try some decent 91 octane or higher fuel
May have been the knock sensors causing the issue due to poor quality fuel