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really awful
Crashes / Fires:
1 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
69,018 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2009 Mercury Mariner engine problems

engine problem

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2009 Mercury Mariner Owner Comments (Page 2 of 2)

« Read the previous 20 complaints

problem #18

Aug 042011

Mariner 4-cyl

  • 92,912 miles


I was on a high traffic freeway coming home from a maternity appointment (I was 7months pregnant and it was hot) and going 70mph middle lane. When my car just cut off. I was still moving but my dash was off check engine light came on and I pulled to the side. I could get it started back up but it went off again. I finally got off on a ramp. I had to have my car towed and rent a car. Between the tow rental and work on my car the total was (est 1400). Then a year later it began every now and then stalling or surging while I was driving. It has progressively worsen. Now it has been when I stop or let off the gas it goes dead. Recently went to an auto shop and they hooked it to the computer. It said it was my throttle body. It was cleaned and all was fine for a week. And now it is doing it again. I finally did google throttle body and Mercury Mariner.I found other complaints.

- Pope, MS, USA

problem #17

Jul 022013

Mariner 6-cyl

  • 65,000 miles
Recently purchased 2009 Mercury Mariner (Ford escape) has three times simply quit while driving at low speed and the throttle is gently pressed. Latest incident was while traveling uphill with two grandchildren and a 18 wheel truck on the back bumper. Luckily my wife had the presence of mind to shift to neutral, re-start the engine, and accelerate away from the truck. No error codes have been set during these three events.

- La Conner, WA, USA

problem #16

Aug 082013

Mariner 6-cyl

  • 45,300 miles
Driving along and unexpectedly engine goes in limp mode with no warning and no acceleration- extremely dangerous as was driving on expressway when this occurred.

- Philadelphia, PA, USA

problem #15

Jul 262013

Mariner 6-cyl

  • 54,000 miles


Driving at highway speeds when the vehicle lost all power. Was able to the vehicles momentum to pull to the side of the highway. After turning the car off, waiting, restarting the vehicle, I was able to restore power to the engine to return home. Turning left through cross traffic, the vehicle lost power again. Was able to quickly turn the vehicle off then on again to restore power and move out of the way of oncoming traffic. The dealer diagnosed and replaced the throttle body for being defective. The vehicle is no longer under warranty and I was required to pay. This is the second time this problem has happened. 1.5 years ago the same problem happened and the throttle body was replaced under warranty.

- Austin, TX, USA

problem #14

Jul 052013

Mariner 6-cyl

  • 50,000 miles
About four weeks ago I had noticed that the gas pedal of my car was acting strangely; occasionally, as I was trying to accelerate from a stopped position it wouldn't work, or "catch, " right away, and I would have to push down increasingly hard until it moved. I had an appointment at my local dealership when I was driving home one Friday, stopped at a stop light to turn left, and it stalled. I brought it in the following Monday morning and after a couple hours the service advisor and technician told me I needed a new throttle body. They tested it and said they could see it "sticking." However, and this is where my complaint comes in, they told me a new part wouldn't come in right away as it was on backorder and there were 48,000 orders besides mine! it has since been 3 weeks since that visit with no new part and no expected date, and the service advisor told me today when I called that there were close to 750,000 orders for this throttle body because it's the same part used in many different vehicle make and models. Regardless, my car is progressively getting worse. When I push the gas pedal I more frequently get no action and at times it now also accelerates unnaturally fast, almost jumps, then quickly returns to normal. Yesterday the pedal required so much force before the car moved that I thought it had stalled on me again, only this time while I was driving it. The dealership has told me that they have no idea when the part could come in and cannot give me a loaner car for an unlimited amount of time, so until then I am driving around in unreliable vehicle, never quite sure how it's going to act. It infuriates me that there are so many of these parts on back order, and yet a recall was never issued. Had there been a recall when the other thousands of people had issues I would not have to sit around waiting, while feeling like I'm putting my own life in danger.

- Prattville, AL, USA

problem #13

Apr 032012


  • 35,400 miles
Was driving down country road and all of a sudden felt then engine what I thought was kick out of gear. Had no acceleration at all. Pulled off road and the vehicle was running in a rough idle, but still could not give it gas. Once placed in park the idle leveled out and still no acceleration. The wrench symbol was on. I stopped the engine and waited 10 minutes then restarted engine and everything was ok. For about 3 months. I took into the Ford dealer only to be told there was no code and they could do nothing without it. Problem has gotten steadily worst. And now it is at point where wife can not drive her car! I am driving it and finally yesterday the engine light came on. I ran it to autozone where they confirmed the dreaded P2112 code. I took it to the Ford dealer today figuring alright less than 5 years old and 42,000 miles I would finally get it fixed. No go! although for $106 they did confirm what autozone already told me that the throttle-body was shot and would cost another $430 to fix.I promptly called Ford customer care line and was told that they would contact the service manager at my Ford dealership to work out a payment plan for me to get it fixed still at my cost. This is crazy that I payed over 26,000 for a vehicle that I still owe 11,000 on and under 5 years old with 42,000 miles and this is my 3rd major problem with it.. have already had the engine pulled apart once to be fixed and one of the drive shafts had to be fully replaced. This is unfortunate but will be the last Ford I ever own!!!

- Elgin, SC, USA

problem #12

Jul 232013

Mariner 4-cyl

  • 126,000 miles


Driving about 40 mph vehicle lost speed. Could not accelerate. Came to a stop point had to turn off vehicle. Turn back on and was ok. Happened twice. Went for a diagnostic and was reported a problem with throttle actuator control system -.stuck closed. "??? check with dealer $435. Check online and found out that Mercury Mariner is having this problem but no recall "

- Clearwater , FL, USA

problem #11

Jul 052013

Mariner 6-cyl

  • 97,100 miles
Car stalls and/or otherwise looses motive power at all speeds (start-up, low speeds, as well as, mid and high speeds) causing dangerous situations on the highways. The part (electronic throttle body) needed for this repair was originally back-ordered 7-8-2013 with expected delivery date of 8-7-2013. Now the expected fulfillment date is 9-23-2013. This is an incredibly longtime to wait to have a car fixed. Can anything be done to expedite this unrealistic time line. How many of these failures do they have" is a recall warranted"

- Bloomfield, MI, USA

problem #10

May 312013

Mariner 4-cyl

  • 111,000 miles
2009 Mercury Mariner engine stalls, surges then no acceleration. Coast to side of road, while trying to not get rear-ended. Engine still runs, is extremely rough. After turning the ignition off, then wait and restart, runs okay. This has happened on many occasions in past month and half. I contacted Ford dealer and service guy says it is most likely the throttle body starting @ $500 repair not covered under the warranty. Happens at any speed. From start or just while driving. First incident 5-31-2013.

- Indianapolis, IN, USA

problem #9

Jun 072013

Mariner 6-cyl

  • 33,800 miles
Driving up ramp to get on 95 car started slowing down after I gave it gas to get up ramp. I noticed a wrench light illuminated on dash so I pulled of manual after turning off car to see what it meant (throttle) I sat for 5 fives started the car and it drove fine, but since then it has happen 3 more times.

- Baltimore, MD, USA

problem #8

Jun 072013


  • 32,000 miles


While I was driving the car jerked as if I hit my brakes and it wouldn't let me accelerate anymore so I pulled over on the side of the road and the car was vibrating real rough so I turned the car off and sat there for a minute and tried starting it and it took a couple tries and I got down the road and pulled into where I was going and it did it again as I was pulling into a parking spot. I really hope this problem can get resolved soon with no cost iv done everything I can to my car to keep it in good condition as in getting the oil changed in it every three thousand miles and even putting the best gasoline in it at $3.65 cents a gallon so its time for Ford/Mercury to support there side of the situation.

- Little Rock, AR, USA

problem #7

Jun 182012

Mariner 6-cyl

  • 46,000 miles
When being aggressive with the accelerator the engine stalls and the accelerator stops working forcing the driver to pull off of the road. When bring the car to a stop it jerks forward until it is put into park, still the accelerator does not work no matter how pushed. After turning it off start up takes longer than usual and either the little wrench or the engine symbol appears. After taking it to a mechanic it is diagnosed that is has a bad electronic throttle and it will have to be replace. Prior to this there has not had an accident, instance or work done that would cause this.

- Ponte Vedra Beach, FL, USA

problem #6

May 242013

Mariner 4-cyl

  • Automatic transmission
  • 87,000 miles
The contact owns a 2009 Mercury Mariner. The contact stated that while driving 65 mph, the vehicle lost acceleration power then stalled. The vehicle was moved to the shoulder and restarted then the check engine light illuminated. The contact took the vehicle to a dealer, where they ran a diagnostic test and stated that the accelerator was defective and needed to be replaced. The vehicle was repaired but the failure recurred. The contact took the vehicle back to the dealer but no defect was found. The failure mileage was 87,000....updated 07-10-13

- Grain Valley, MO, USA

problem #5

May 192013

Mariner 6-cyl

  • 40,850 miles
This is the fourth time since purchasing the car at carmax in October 2012 that the car has "shut off" without warning at low speed when close to parking or driving slow--without rhyme nor reason--I had it diagnosed at carmax to no avail, then Cherokee Ford to no avail (where I purchased a new battery), then at christian brothers auto where they replaced the spark plugs and coil.( I have an extended warranty so my cost was 200dollars) the problem continues. I have done research and see the throttle body is most likely the culprit and a safety alert is on the web from consumer report and Ford forum and North Carolina safety board---I am having the trottle body replaced at my expense--my daughter drives this vehicle and I want it safe! apparently this involves this model 2009-2012.

- Johns Creek, GA, USA

problem #4

Apr 262013


  • 83,000 miles
While driving my car suddenly began decreasing in speed, it appeared my gas pedal had been disconnected. The car was still on so I turned it off and back on and it worked fine. For a month before hand my car would make a loud bang and jolt when ever I switched between drive, reverse, park etc. When presenting the problem to Ford they were very rude but explained I had heard about this issue online. They finally looked at the car for me and were given an error code (of P101 I believe).

- Stratford, NJ, USA

problem #3

Apr 232012

Mariner 6-cyl

  • 65,000 miles
The contact owns a 2009 Mercury Mariner. The contact stated that while driving approximately 50 mph, the vehicle abnormally accelerated. The contact applied the brakes and was able to stop the independent acceleration. The failure recurred three times. The manufacturer was made aware of the failure. The vehicle was not repaired. The approximate failure mileage was 65,000.

- Mt Pleasant, MI, USA

problem #2

Jan 072012

Mariner 6-cyl

  • Automatic transmission
  • 26,006 miles
The contact owns a 2009 Mercury Mariner. The contact was entering a parking space when the vehicle exhibited an abnormally loud revving sound and accelerated into a fence without warning. There were no injuries nor was a police report filed. The contact was able to secure an appointment to have a diagnostic performed on the failure. The manufacturer was notified of the failure but the vehicle was not repaired. The failure mileage was 26,006 and the current mileage was 26,011. Updated 02/09/12 the consumer stated the body damage was repaired. However, the vehicle continues to accelerate. Updated 02/13/12

- Livonia, MI, USA

problem #1

Dec 092009

Mariner 4WD 6-cyl

  • 15,000 miles
2009 Mercury Mariner. The rear end of the vehicle makes a squealing noise upon acceleration I took the car back to the Ford dealership in hillsdale. The vehicle was in the shop 12/9/2009 through 12/16/2009. Unable to fix the noise, Ford Motor Company had them tear down the transmission and replace the drive chain. When I picked up the car I was told that the noise was still there and that Ford engineering said it should not be a problem. The noise was still consistent and has grown increasingly louder. Since this initial complaint I have received a recall notice for the transmission solenoid regulator valve. The vehicle has been accelerating when it shouldn't and not accelerating when it should, like when merging into traffic when the transmission would not perform properly.

- Adrian, MI, USA

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