2008 Fusion V6 SE stuttering while driving

[Ford9n]

I have a 2012 Fusion, has the 3.0 V6, with about 11,000 miles. I like driving the car, but it has a problem that my local AutoNation Ford dealer and the Ford region service person could not diagnose. I drive mostly in the city and generally the car runs fine. But at a constant speed above 65mph, the car develops a noticeable stutter or hesitation. It almost feels as if it has an engine miss, or as if the brake is rapidly being applied. It accelerates fine and seems to shift okay. It does not seem to matter if cruise control is activated. Place the car in neutral, the problem is gone. The problem has not triggered a service light. On longer trips, this problem is annoying.

The dealer acknowledged the problem, as did the Ford regional service person, but they do not have a solution. I have been told by the dealer other V6 Fusions also have this problem.

I have seen a few other internet post expressing this same problem [and frustration], but have not seen a fix. Any ideas?

[FusionDiffusion]

Hmm, yes that sounds like a problem that would be difficult to track down without some extended testing. Does it do it with your foot off the gas while still in drive? Is it sort of a light jerking or more like the engine is dropping out completely? Does it do it all the time while going more than 65 MPH or just sometimes? If you go faster (like 80 MPH) and take your foot off the gas does it do it in a certain speed range or at any speed above 65?

[Ford9n]

It is more like a 'jerking' feeling. The car does not do it under moderate or aggressive acceleration or deceleration, just when the car is cruising at a steady speed. It is noticeable enough for passengers to comment. It is most pronounced between, say 65 and 75 or 80 [although you can feel it from time to time at lower speeds]. When at a constant, steady speed, it is nearly continuous. I have not had the car consistently above 80, tough to do in NE Ohio. The dealer had the car for about a week, checked various systems, but did not replace anything. There were no software updates available. The dealer did rebalance the tires.

 

[FusionDiffusion]

Well what I would do is hook up a scan tool and do some data logging to see if you can catch anything abnormal. Not sure if you have an OBD-II scan tool or not, but you can buy an ELM327 for only about $10-20 online. If you log the data I can take a look at it.

[con_fusion]

sounds like this thread - http://www.fordfusionforum.com/topic/9207-bucking-at-constant-highway-speeds-2012-sel/

[Ford9n]

Con-Fusion, that is it exactly the problem my 2012 is having. May take FusionDiffusion's advice and purchase an ELM327 to see if I learn anything, but I am quickly becoming of the opinion its a lemon and should be replaced while the dealer is still willing to give me something for it (although I would feel bad for the next person that gets stuck with it). Are the 2013's any better?

[Ford9n]

Update. Problem is not fixed, but I have noticed the stutter / hesitation occurs around 2100 to 2500 rpm in 4th, 5th and 6th gears. Can't tell if the hesitation / jerking happens in gears 1 through 3. Does not have the problem when in 'Park' or 'Neutral' at this RPM, so it seems there must be some load on the engine for the misfire type feeling to occur. From other postings, it doesn't appear the MAS is the issue. Would the DPFE or EGR cause this problem? When the car was about 2-3 months old, and for the following 3-4 or so months, there was a mild smell of burning plastic from the engine compartment. Related? Car has just over 12,000 miles and still not throwing a code.

[Marvin Crompton]

Its unlikely a dirty MAF, but you never know (clean it anyways). I would go in the direction of a fuel related concern. Either the fuel pressure is not what it should be with higher engine loads or dirty fuel injectors. I would think that if this was the case, the symptoms would be a little more consistent. A faulty injector that becomes electrically faulty only when the temperature is high enough. The injectors themselves have resistance, and the faulty injectors resistance may change at high temperatures making it unstable and cause intermittent injector problems (thus a misfire). Only automotive oscilloscopes can find such issues though.

[Noahfreak]

Did you end up figuring this out? I've got a similar behavior coming from my 2012 SE 3.0. It's most noticeable when cruising at highway speeds, because of the constant load on the engine, but I have noticed the miss at idle rpm. You can barely tell when it's idling, but I'm pretty dialed in to this sort of thing. The only time I don't notice it is when I'm accelerating. It feels like the old points ignition setups on carbureted engines from the 60s. You never really could completely eliminate a miss from those ignition/fuel systems. Considering that this has coil-on-plug and sequential port fuel injection with 4 valves per cylinder, it should be smooth as silk when working properly.

I was leaning toward coil packs or the ground connection on same as my first place to look. Mine did a little bit of sitting in a dirt lot before I bought it used so I imagine a little moisture condensate and corrosion could have gotten in somewhere and I may just need to clean the connection. I know Fords used to be notorious for bad grounding issues back in the day, so I'm wondering if this is still the case? I also thought about the rubber boots around the stem of the coil packs. If those were to leak voltage at all, I could see this happening. I had an old Saturn with similar behavior and it turned out one of the plug wires had wiggled partially loose from the plug and was intermittently ground arching into the cam cover.

[FusionDiffusion]

Weak ignition or voltage leakage could be a cause, since low RPM/high load puts the most stress on the ignition system components.

[Noahfreak]

It occured to me earlier today that this might be a sticky EGR as well. I had an old Saturn that did this only while cruising with tiny throttle changes. I pulled the EGR off and cleaned all the carbon out and it fixed the issue on that car. I'm curious to know if this is possible on a mass-air car with drive by wire throttle. If it is, it might seem more random too because throttle pedal inputs don't always translate linearly to the engine.

The Fusion sat for a while before i bought it, so I'm going to wait until I run a few more tanks of fuel through it. It's only on the second tank and this behavior has started to come and go already. It also feels like it pulls a little harder than it did the first few days. Had it out today and felt a lot torquier. Maybe it was just some stale fuel getting flushed out of the system.

[JAO]

The 2012s have a known throttle body assembly fault. It may be replaced under a recall - check with your dealer. Also check into a possible fuel pump recall. I've heard there have been a lot of fuel pump replacements performed on the 2012s.

[wjcollier07]

I've been experiencing this issue since I got my '11 at 35k. 2 years later, just turned over 80,000 today and the stumbling has only gotten worse. It feels like what you'd expect to be a bad misfire or a failed/failing ignition coil. If you're pulling up a long grade and holding a gear near the peak torque point, the stumble is bad enough where you can watch the tachometer shake right along with it.

 

To address the issue, I've already changed the plugs (with OEM, of course), I always run TopTier fuel, I run Fuel System Cleaner (PEA based) every 6 months and run Amsoil Signature. I couldn't possibly maintain the car any more impeccably. I even change the ATF every 30-40k miles (twice since I bought the car). In addition to that, my throttle body failed about a year ago, and was replaced by the dealer (prior to it being a CSP)

 

With all of the different conditions I've driven the car in, extremely high heat, extreme cold, flat high speed highway, mountain roads to very high altitude, snow, ice, etc. (anything you can do with a sedan in the continental 48), I'm beginning to think it's not the engine at all, and it's actually the transmission.

 

I can't really explain why, but I do know that my '07 (with the AWF21) is SO smooth and so perfect compared to the bumbling stumbling '11. While I understand there is a substantial difference in the engine, which is what gives the newer generation an extra kick in the horsepower dept, I can't see how there doesn't seem to be the same issue with the 3.5 cyclone (even though that's also a very different engine, it shares many of the same top end components as the duratec 30 in its latest generation.

 

Please tell me there's a light at the end of this tunnel. It's getting worse, I'm getting very irritated by it, and I plan to have the vehicle for another 4 years, or until about 140,000 miles (can't wait to see how bad it'll be by that point)

[crash525]

I am glad I had found this. I have a 2012 3.0 sel certified preowned crap with 19,000 miles. I posted my same problem on here and I got no reply. I am having the same issue. it happens at any speed while cruising between 2,000-3,000 rpms. It feels like I am pulling a trailer (trailer hitching motion). I took my car to three different dealer and they notice the problem but cant find out what is wrong. After a few attemps they just tell me that its how they all operate.I drove a few different cars all the same though and they have never done this. Anyways. One dealer had "neutralized my motor mounts." They the motor had shifted a bit and since then, the problem happened more frequent and at a more broad rpm range. I took it to a different dealer today and they said they have a good idea on what it is but it doesnt go back in for a few more days. I will see if they can fix this.

 

Has anyone noticed the motor mounts are very sloppy in these cars? alot of free play and they bottom out alot too. Also does anyone notice the car shutter/bounce/jerk when they let off the throttle after accelerating or cruising? Mine does. Its horrible.

 

I have lost all faith in ford. This is my second fusion. The first one the dealer could not fix so they got me into another one. Same everything except the motor. The first one had the 2.5l. I have had both blower motors go out and the new one that was just replaced is going out(chirping noise), sync malfuntioned (common issue), horrible idle on the 4cyl, blendoor go out on the first car, ABS go out on the first car, horrible shifting from both cars, short and consistant acceleration and pause and acceleration issue on the first one, low rpm growl(sometimes at idle or accel) on the second car, and I think that is it. I regret trading in my 2006 jetta tdi for these cars. its sad to say my 8 year old car with 6 times as many mile had more features, idled smoother, ran better, and had less problems. The only reason I got rid of it was because it started to rust. I had high feelings toward ford with previous vehicles but not after this.

 

I will post back up after my car has gone to the dealer. Also fords region customer service managers really suck and are horrible at their jobs. They say that they will call within 24 hours and never do. Even after calling back multiple times they never call back. The fasted call back I got was within 3 days and the longest time I waited was 7 days.

[wjcollier07]

Try premium fuel. I've been chasing mine for so long until recently when I changed out the transmission fluid to Redline D6 and added LubeGard Red, which helped the shudder slightly, but only today have I noticed any significant difference with a full tank of 93 octane. I'm still in the early stages on anything definitive, but try it for a few tanks, see if it works!

[crash525]

Well I think my dad and I have figure it out. It is a combination of flimsy motor mounts along with free play in the transmission and how the stupid throttle body functions. My dad is a seasoned mechanic auto btw. Heres my conclusion. While cruising and there is no real load or tension on the motor, the motor mount will relax since the car is cruising and then will eventually get a load since the mounts move so easily. When the load occurs you will get that back and for trailer hitching motion. The motor will bounce since the mounts are weak and the car is cruising, nothing can hold the motor from bouncing. Hence you dont feel it while acceleration and you feel a few small bounces when you let off the throttle and about every time the car downshifts. Since there is also free play in the transmission this adds to the effect of the motion. Now heres my take on the throttle bodies part in the issue. Since ford decides to mainly run the throttle body WOT ( from what I hear and see on graphs) the pcm has to adjust with timing and fuel adjustments, the pcm cannot adjust fast enough to prevent the trailer hitching motion. Basically the car and the pcm are in a weird spot while cruising because of how they have the throttle body operate.

 

If you want to get the car to do the motion bad if you have a manual shift on your car get to 40-45mph and put it in manual mode, shift to 4th gear and cruise. It will be more prevalent doing it like that.

 

Try this, when the car is parked and the car off pop the hood and rock the car back and forth till the motor mounts bottom out and bounce back. You will hear the free play in the transmission and you will notice the car move alot between the rocking.

 

I doubt ford will do anything about this because this issue will not injure or harm anyone/thing.

[akirby]

What do you mean mainly run the throttle body WOT? That would max the rpm.

[crash525]

Yea I thought the same, it would rev out completely. But I guess that ford opens the TB all the way while under an acceleration to reduce wind drag by the butter fly. They compensate this with timing and fuel changed. If you have a chance to monitor your TB while driving then you will notice while cruising with you foot on the pedal just a small amount the TB is open almost all the way. Stupid idea. Overly complicated and makes the driveability of the car less than desired. While you foot could be at 1/4 throttle the TB will possibly be at 1/2 or more. Under small acceleration the TB open WOT. Unless the car has valve timing ( im not sure if it does) then changing timing and fuel will not be beneficial in any way because the car will still take in more and cause it to run lean.

 

I hate how ford has this set up because the car is unpredictable. The way the car drives changes every time. Its not consistent. Oh well. I still have not yet heard back form ford regional customer service managers. Its been over a week since I had called.

[akirby]

I don't see how it can work that way. You can't compensate for a wide open TB with timing and fuel changes to prevent the engine from revving higher and using more fuel.

 

Reducing "wind drag" on the butterfly also makes no sense.

 

I think you're misinterpreting the data.

Edited October 6, 2014 by akirby

[crash525]

I will attach data from my flight recorder data. Yes it does not make sense at all. But when the throttle is WOT and the car is under a load it will not rapidly increase engine rpm. That equals less air flow, and the computer uses less fuel and changes the timing. Its like getting in a manual car going 30 mph and putting it in overdrive and flooring it. The rpms will increase slowly it will still accelerate.

 

In the file there are a list of PIDs.

 

APP2 is accelerator pedal actual and that is what the gas pedal is at.

APP1 is accelerator pedal desired and that is what the computer wants it to be at.

 

ETC_ACT is electronic throttle control actual (throttle plate) where the throttle plate is at, (degrees open, I think 81 degrees is WOT)

ETC_DSD is electronic throttle control desired where the computer wants the throttle plate to be.

 

FP is fuel pressure.

 

The graph is recorded in seconds. It only recorded 8 second, 4 seconds before the button push and 4 seconds after.

 

The recording was taken in 3rd gear and there was no shifting up or down.

 

As you can see the cars pcm wants the car to run WOT when you only want it to run at 25%.

 

If you have a different explanation to this then let me know.

image2014-08-18-094230.pdf

[akirby]

If that's accurate then my first guess is it's somehow tied to cylinder deactivation.

 

I think app1 and app2 are the 2 accelerator position sensors - one is 0-5v and the other is 0-2.5v. App is the normalized result so in this case your throttle was at 55% not 25%. It compares the results from app1 and app2 and if app1 isn't double app2 then there is a fault. At least that's my interpretation.

[crash525]

That could be true. I was told by two ford techs. I dont take what they say to heart. Anyways, notice how the pedal position is at a certain % say even 55% open but the throttle plate is at 100% open. Since it is a drive by wire they can program what ever they want to make it do what they want. I have not heard of these motors having a cylinder deactivation feature. They could have the egr valve open all the way when this happens choking the motor out so the throttle plate can be opened all the way along with adjusting the fuel and adjusting the timing. I think the way the throttle plate works is flawed and overly complicated.

[akirby]

If that's true then ask yourself why they would make it so complicated?

[crash525]

Because engineers have to make things complicated.

[akirby]

Because engineers have to make things complicated.

 

Not without a really good reason.