2014 SHO Surging / Loss of Power

[LipschitzWrath]

Car is a 2014 Taurus SHO, non-pp, 155k on the odometer. Car is driven almost exclusively on the highway and doesn't get beat on very often. I'd say it lives a pretty dang easy life.

Anyways, a month or two ago I noticed that the car would surge when accelerating. It seems more noticeable when going uphill. The RPM's bounce with the surging maybe 200 RPM's or so. It started out barely perceptible, but is gradually getting worse.

There also seems to be a loss in power. The car is still strong, just doesn't seem as strong as before.

The car sounds normal, and no CEL.  Mileage seems unaffected. My last two tanks have been 24.0 mpg.

I replaced the spark plus about two months ago with NGK Iridium. No improvement.

I was leaning towards coils next, but that's $180 that I would prefer not to guess at.

Ideas?  Tests I can run?

I heard of doing a KAM reset? Maybe a throttle pedal reset?

Thanks in advance!

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[Ta2dResqr]

What do your LTFT and STFT look like? Any pending codes? Any knock, misfire on a scanner when under load? What did you gap your plugs to? Any mods or a tune? Are you using Top Tier 93 fuel? Last time you did an intake cleaning or fuel injector cleaning?

 

[LipschitzWrath]

What do your LTFT and STFT look like? Any pending codes? Any knock, misfire on a scanner when under load? What did you gap your plugs to? Any mods or a tune? Are you using Top Tier 93 fuel? Last time you did an intake cleaning or fuel injector cleaning?

I don't have a scan tool, so I couldn't tell you about the fuel trims, long or short term.

Perhaps now would be a good time to ask what a quality scan tool is. As I understand it, downloading Forscan is pretty popular. What are people using for OBDII adapters? Do they make a bluetooth one so I can use my phone?

What is a "pending code"? I have no check engine light so I know of no codes. I don't believe this car has ever thrown me a CEL.

No knock or misfire under load, but not watching it with a scanner.

I did not gap the plugs before installation, I just threw them in. The plugs I bought are advertised as having a gap of 0.032". Since they are the one thing I have replaced since this started, I'm thinking they are going to be lower priority on the troubleshooting tree.

No mods or tune on this vehicle.

No change in fuel quality on this vehicle since, like, ever, but certainly not since we'll before the problem started.

Have never done an intake or injector cleaning.

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[Ta2dResqr]

I highly recommend a scan tool. If you are going to use ForScan, they have 2 models they recommend. They are both by OBDLink. The Bluetooth model will link with your phone. The phone app will not program modules and is limited in function. I do not recommend the Bluetooth model for anything except reading data. I personally have both the Bluetooth and the wired versions.

Most plugs are "pre-gapped", however, I always recommend checking them. Think about how packages arrive on your doorstep. From the moment they are gapped on the production line, all through manufacture and packaging, during shipping and stocking, and up until the moment they are installed, they are susceptible to be changed.

These motors are direct injection and as such, no fuel travels through the intake system which allows the extra build-up of carbon from recirculated oil via the PCV system. I would suggest an intake/upper engine cleaning of some sort (SeaFoam, BG, CRC, etc.). Along the same lines, a fuel system cleaning periodically is good maintenance. When a motor is under high load, everything has to work harder/faster. Items that are beginning to have issues will usually show under load first.

A pending code is something that has not met the criteria yet to set a hard code. They are generally visible with a good scan tool.

Knock and misfire may be below the threshold to set a code or be physically felt but beginning to affect engine performance under load. I would check all the fuel trims, knock, misfire, etc. counts when you get a scan tool.

Fuel quality is a question because if you have not been using a top-tier fuel for an extended period of time, this may have led to build-up and deposits.

I would start with getting a scan tool if you are going to begin troubleshooting yourself. The next big thing is a service manual. Both of these will help you determine if it is a fuel, ignition, etc. issue and how to properly service it.

A KAM reset is a Keep Alive Memory reset. These are fuel trims, ignition curves, shift points, etc. Anything the vehicle uses to learn slight differences from your vehicle to the ones before and after it on the line. It also adapts to a certain degree to your driving style. If you do a KAM reset with no big changes, this may prolong your diagnosis. Usually, a KAM reset is done after a tune, large component changes, etc. By resetting the KAM, your vehicle will use a set of factory defaults until you complete enough drive cycles for the system to learn all the nuances of your system and driving. The vehicle will not feel or act the same until is has gone through it's complete learn cycle.

 

[LipschitzWrath]

Thanks.  If I go with Forscan, I will make sure I get the wired adapter for now. My wife has a Surface that would work well for this.

Two questions.

Would you recommend something OTHER than Forscan?

For this issue specifically, do you see me needing any capabilities beyond what the wireless version provides? Can the wireless version perform data logging or is that wired connection only?

Hopefully there will be some pending codes or other data to help narrow my search. For some reason I just have a nagging feeling it's a coil.

I will look into intake and injector cleanings.

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[Ta2dResqr]

Personally, since the free trial of ForScan is renewable and the corded connector is cheaper, I would start there. I would also set a price alert for MSD coils. I was able to pick up a set of 6 for about $150 on Amazon.

 

[LipschitzWrath]

Personally, since the free trial of ForScan is renewable and the corded connector is cheaper, I would start there. I would also set a price alert for MSD coils. I was able to pick up a set of 6 for about $150 on Amazon.

Thanks.

So you agree that the coils could be a suspect (admittedly among many)?

I was looking at another set of coils, not quite as nice as the MSD, but not bad. I think they were listed for $180.

Were the coils you bought used or new?

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[Ta2dResqr]

"Used". Amazon Warehouse sells any previously sold item as used. The box I received was defaced. There had been a shipping label on the front. They cut it off leaving the box damaged. Everything inside was sealed and there was not a single mark on the coils or boots. I would stick with Motorcraft, Delphi, Denso, NGK, Standard, or MSD, one of the bigger company names.

Yes, coils could be of concern. You should be able to see that on the plugs though. If they are not burning well, the plugs will show it.

 

[SHOdded]

rpms bouncing without change in throttle input can be a sign of a bad torque converter.

what is the transmission fluid maintenance history?

 

[LipschitzWrath]

rpms bouncing without change in throttle input can be a sign of a bad torque converter.

what is the transmission fluid maintenance history?

I just did a drain and refill with Motorcraft at 150k miles. That's what the owner's manual says. Is the consensus to do it more often than that?

For what it's worth, the fluid didn't look bad at all when I drained it.

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[LipschitzWrath]

rpms bouncing without change in throttle input can be a sign of a bad torque converter.

what is the transmission fluid maintenance history?

Just thought to add this - while that would certainly explain the RPM surging, I don't think that addresses the loss of power.

Said loss is somewhat sporadic. Sometimes I jump on the throttle and it goes like normal, other times it's like driving a Prius.

About 2 week ago, I mashed the throttle to get in front of a semi before a construction zone. The car kicked down and the engine get loud, but there was no acceleration. I wound up having to abandon the pass.

To me, that tends to rule out the transmission.

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[Macgyver]

Only way to be sure would be to Log it all the time till it happens and see what the log says.

 

[LipschitzWrath]

Only way to be sure would be to Log it all the time till it happens and see what the log says.

Agreed, and that's my plan as soon as I get some time.

It appears the TCM just failed in my wife's truck so I am currently dealing with that.

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[Macgyver]

Well that sucks.......

 

[LipschitzWrath]

Yeah, going through a bit of a spat.  Fortunately, the TCM is about a 5-minute fix since they mounted it on the fan shroud.


The down side is it costs $750.  Such is life.  My wife gets stressed out about stuff like this.  We paid the truck off like 3 years ago.  Whenever something like this happens, I have to remind my wife that shelling out $750 is pretty cheap compared to the payment we would be making on a new one.


As for the Taurus, it won't be too hard to log the event.  There is a hill on the interstate on my way to work that the car does the surging thing every single time.  I plan to log it and then dissect the data.  Speaking of that, it will take me a minute to get up to speed on Forscan.  Does it have the option to log everything or do you have to select individual PID's?


I should have paid closer attention to the old spark plugs when I replaced them.  I feel like one or two of them maybe looked a little different.  Of course I threw them away and have no clue which is which.

 

[Night Hawk]

https://youtu.be/vrhBu5XtafU

Id check all the vacc lines, especially involving boost.  It happened to me at the track one year no codes, no other symptoms just waaay down on trap speed. Found the line that popped off, reconnected with a zip tie, good to go.

Good luck!

 

[LipschitzWrath]

https://youtu.be/vrhBu5XtafU

Id check all the vacc lines, especially involving boost.  It happened to me at the track one year no codes, no other symptoms just waaay down on trap speed. Found the line that popped off, reconnected with a zip tie, good to go.

Good luck!

DING DING DING! WE HAVE A WINNER!

Just popped the hood to check this and the exact hose connection in the video was off.

I haven't had a chance to test drive it yet but I'm confident that's it.

For now I reconnected the hose and zip tied it. Anyone know what size and type hose for that connection?

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[LipschitzWrath]

Alright, today was the first time I've driven to work since the issue was discovered. I'm happy to report the car is back to normal 100%. I'd consider this issue resolved unless something else comes up.

And for those following along, a new TCM resolved my wife's truck problems. Less than 5 minutes to fix. Too bad it cost me $750.

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