2007 Mountaineer problem

[mercuryconnor]

I did some searching but I don't know much about cars so I don't know if the posts I read described the same problem as mine or not.

I own a 2007 Mercury Mountaineer Premier AWD V8. The car has 67,000 miles on it and I am the third owner.

When starting out in drive while the engine is cold, the car accelerates very sluggishly and jerky. This is slow acceleration where I notice it, like when driving through a parking lot or when you're at a red light that turns green, but you're stuck behind a huge 18 wheeler truck and you are stuck accelerating slowly behind them. During this slow acceleration the car really jerks around instead of going at a smooth pace. I don't notice this as much when the engine is warm, nor do I notice it when I do quick accelerations.

The other problem I have happens only about half of the time, and it's whenever I approach 50mph. The car starts to shake violently, and I can feel tons of feedback in the gas pedal. It feels like it's slipping out of gear or something. When I ease off the gas pedal, the shaking gets worse, however if I floor it, it goes away (maybe because it downshifts?) I've gotten the car up to 75 or 80 before and it stays well below 2,000 rpm's, so I know it can get into whatever gear that is. I don't know the proper terms for this, the only thing with cars that I am able to do on my own is change my oil. I don't want to automatically say this is a transmission problem, because in the past I've had similar problems with other brands of cars and it's turned out to be anything from sensors to software.

Does anyone know what might be causing these two problems? Could they be related? Is there a known fix for this?

The car is under warranty for another year or so, or until 100,000 miles, but I expect the time limit will expire before I reach 100,000 miles.

 

[mad_4u]

Do you have any Error code or check Engine light?
you need to check your
spark plugs, coils & Fuel filter.

 

[mercuryconnor]

No error codes whatsoever. I bought the car somewhat recently so I have no idea what the maintenance history is. No clue when the transmission fluid was last changed or any of that.

 

[PotatoExplorer]

Hmmm, I feel like I have the same problem you listed first. I think it's just the nature of how Ford programed these vehicles. It's like when you start the vehicle and try to drive nice and slowly to let things warm up a bit before getting up on the gas, the transmission just doesn't want to up shift so it just hangs in first gear all while revving up higher and higher. Eventually it lets go and shifts up but kind of slams into gear. I've been contemplating on going to the dealership to get the programing updated... not sure if it will fix this issue though. It's more annoying than anything. It seems like as soon as it shifts up into 2nd gear, the problem doesn't reoccur unless you shut it off and let it sit for a while and try to start it up again.

 

[mad_4u]

if you just got the car and you do not have clue of the maintenance history, you should service it 1st.
Change All Oils including transmission oil and filter,
change the spark plug, air filter, fuel filter.

it could be the transmittion oil is low or old and It takes time to distribute it inside the gearbox.

 

[mercuryconnor]

if you just got the car and you do not have clue of the maintenance history, you should service it 1st.
Change All Oils including transmission oil and filter,
change the spark plug, air filter, fuel filter.

it could be the transmittion oil is low or old and It takes time to distribute it inside the gearbox.

Thank you, I will take it in to my mechanic today, have him look it over and go ahead and replace the transmission fluid. Since the check engine light is off and there are no codes (no pending or stored codes either) I don't believe it is a misfire issue.

 

[thebrakeman]

Sounds like a bad plug or coil. I was going to recommend you check for pending codes, but looks like you checked that.
Either way, sounds like a bad plug or coil. It typically manifests at moderate throttle, but not enough to induce a downshift. The load on the engine is heavy at a throttle position just before kickdown. The downshift reduces the load on the engine, and the stuttering goes away.

What type of gage are you using to check for codes?

 

[mercuryconnor]

Thank you everybody for the advice. I had the trans fluid, filter, and gasket changed out yesterday. I no longer notice the inconsistent acceleration at low speeds while the engine is cold. It accelerates smoothly and drives better now. I haven't yet driven on the highway so I can't comment on whether or not the gear slips when it reaches 50mph, but so far so good.

My mechanic said it's possible the sparks plugs may be worn, but he said they aren't bad and aren't worth replacing just yet. He confirmed there are no misfires.

 

[tripplec]

You had better hope he used the Correct transmission fluid. It won't last long otherwise and a new transmission will be next. They are not forgiving. They should know and double check in this day and age with so many different fluid requirements out there. They are not compatible with many of the other fluids used.
Just saying.

 

[mercuryconnor]

You had better hope he used the Correct transmission fluid. It won't last long otherwise and a new transmission will be next. They are not forgiving. They should know and double check in this day and age with so many different fluid requirements out there. They are not compatible with many of the other fluids used.
Just saying.

The invoice said OEM Mercon fluid.

 

[Explorer_PL]

There are 4 Mercon fluids I know of:
Mercon (plain, no longer manufactured I believe)
Mercon V
Mercon SP used in our cars with v8/6R60 2006-2008
Mercon LP used in our cars with v8/6R80 2009-2010

Those triton engines need significant misfire to trigger a code. I have had a bad coils multiple times with no engine light. Only after a while, when it got really bad, it would trigger a misfire error P30x

 

[mercuryconnor]

Well, after a weekend of driving, I can say the transmission fluid change did not help at all. I checked and they did put the correct fluid in. However, driving on the highway the car felt like an earthquake every time I approached 45-50 mph and it wanted to change into the next gear. Once again the only relief from that was flooring it, as easing off the gas pedal made the shaking worse. I was able to get it up to normal cruising speeds (about 75 mph) and it drove fine there, but passing 45-50mph was difficult every time.

 

[tripplec]

Sounds like an internal problem and/or solenoid controlling he shifting. You can check with a transmission specialist at a shop. A small private one rather than a big chain may be more inclined to fix the problem rather than just say you need a rebuild and do the entire transmission.

 

[tripplec]

There are 4 Mercon fluids I know of:
Mercon (plain, no longer manufactured I believe)
Mercon V
Mercon SP used in our cars with v8/6R60 2006-2008
Mercon LP used in our cars with v8/6R80 2009-2010

Those triton engines need significant misfire to trigger a code. I have had a bad coils multiple times with no engine light. Only after a while, when it got really bad, it would trigger a misfire error P30x

Last I read the Explorers did not get the 6R80, (Pickups or Expeditions). The 6R60 is paired with the V8 in 2009 and I believe 2010 the last year of this series.

It would be good if I were wrong and a switch was made to the HD transmission.

 

[mercuryconnor]

Sounds like an internal problem and/or solenoid controlling he shifting. You can check with a transmission specialist at a shop. A small private one rather than a big chain may be more inclined to fix the problem rather than just say you need a rebuild and do the entire transmission.

It wouldn't be the end of the world for me if they said I needed to replace or rebuild the transmission as my trans is covered under warranty for another year or so. Side note, the mechanic (not dealer) charged me $385 to do the trans flush. Seems insanely high, right? 6 quarts of Mercon SP, filter, gasket, labor. I chose that mechanic because he is the only one in my area that is approved under the warranty program, and I don't really want to go back to the Kia dealership I bought the car at to have them work on it. Not really sure how it will play out if I need to have a covered repair.

 

[Explorer_PL]

Tripplec -

I am afraid you need to read more about 6R's


And yes, $ 385 is a high.
I just picked up 8 quarts of Mercon SP from Advance Auto and an original Motorcraft filter at a Ford dealer, all was about $ 98 together. I'll be doing it in the next few weeks.

 

[tripplec]

I am always reading hear!! LOL Even though its not my vehicle but my son's.

A dealer wanted about $400 to do his tranny fluid as well when we asked.

 

[tripplec]

Well it looks like its an 80 looking at the PDF now. Hmmm missed that somehow. Now corrected in memory.

 

[thebrakeman]

At 67,000 miles, you are actually at the perfect point to replace the spark plugs. Recommended service is at 100,000 miles, but in case you aren't aware, by that point, may will have 1 or more plugs break inside the head (carbon buildup on long-sleeve plug, thru tight-clearance head), requiring additional labor and money. Previous/original owner of my Mounty changed plugs at around 60,000 for this reason, and had no issues.

The plugs just might be your problem, too. I would change them before letting someone repair/replace my transmission. It may be money spent sooner than you expected, but it will be needed soon anyway. And it's something you can do yourself, as long as you look up the recommended procedure, and use some patience.

 

[Explorer_PL]

Most of the shaking / idle / shuddering issues come down to spark plugs and coils on these engines.
Dealer wanted to replace my tranny for $ 4000 - 5000 and in the end it was my coils.
I said it in some other post, but once you replace them for the first time, go in there every few months, and break them lose and tighten them back.
With proper tools it's a 30-45 minute exercise and you may just save yourself a bigger headache down the road.