Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2003 Ford Mustang owners, lightly cleaned up (personal details are redacted by NHTSA).
We have had issues with this car since it was bought new. All issues have been looked at by the dealer during the factory warranty and still remain unresolved. I have written a letter to Ford headquarters but they sent a complete rejection letter. I was told today by a Ford customer service representative to file a complaint here. I can supply documents and the original letter to Ford if needed. The main issues from purchasing new and driving off the lot are (in rough order of importance): -major paint and clear coat issues (brought to dealer two days after purchase to complain. They have never resolved problem and it has continued to get worse to this day.) -driver door window stops working intermittently. -car engine surging making car lurch forward (my wife was involved in a minor accident because of this. …
Tl* the contact owns a 2003 Ford Mustang. The contact stated that the vehicle experienced a loss of power. Upon inspection, the contact discovered that the spark plug was missing from the engine compartment. While tightening bolts in the engine compartment, the vehicle ejected another spark plug. The vehicle was taken to hollingsworth richards Ford where the contact was notified that this was a known issue with this vehicle. Since there was no recall, the engine head cylinder would need to be replaced. The manufacturer stated that, due to the mileage of the vehicle, the contact would be responsible for the repair cost even though this was a known issue with this model vehicle. The failure mileage was approximately 167,000.
The exhaust pipe breaks where the A/C water drips. This is due to poor design of the car. This article describes it better. Https://Ford.oemdtc.com/100/exhaust-leak-cracked-or-separated-right-side-exhaust-pipe-1999-2004-Ford-Mustang
1) everything was running fine, no problems detected. Maintenance on vehicle was up to date. Was turning a corner and there was a pop and after that the engine started to mis-fire. 2) was able to limp the 2 miles to the Ford service center. There, they told me that the spark plug had blown out of the engine block and that this happens on occasion. I had two options: the first was to pay $610 to put a patch in that wasn't provided with a warranty and they told me it could last 2 years or blow 2 miles down from the shop after I left, or pay $2500 and have a new cylinder put in. After researching this issue, I found that this is a very common occurrence with Ford vehicles, that Ford is aware of but is not taking care of. I was also told that even if the car was still under warranty that the warranty would not cover this and I would still have to pay out of pocket. …
While sitting at the traffic intersection awaiting the light to turn green. I heard a loud pop from under hood and all of sudden the car began to run like crap. I pulled over to check under the car to see if something had fallen off, but I found nothing. I then checked under the hood to find out my spark blew out my passenger side cylinder head. I took it to the Ford dealership for repairs, but my extended warranty would not pay for the repair because they do not cover spark plug damages. This left with a $4,463 repair cost to fix my car that I only owned for three months. While doing research on the internet and asking questions in mechanic shops, it has been apparent that Ford engines have defective cylinder heads and recall needs to be issues in regard to this matter. There are many victims affected by this issue and Ford has done nothing about this problem. …
While slowing down, downshifting or switching gears, the car engine will just fail and shut off/stall without any warning. The car will not "buck" or shake, it will just turn off, causing the power steering to stop operating. I have had two close incidents where I was turning into a parking lot and almost hit a car because the power steering shut off when the engine died without warning. I am afraid this problem will cause a bad accident, especially when I have two young children riding in the vehicle most of the time. I took the car to Ford dealership they stated that they did a full inspection but did not find anything wrong. I am still experiencing the same problem at least several times a day when my engine will just shut off without any warning or notice while I am operating it. …
Purchased a 2003 Ford Mustang with 22,000 miles on it in feb 2005. Had a ticking/tapping sound coming out of engine bay area at 30,720 miles. Took it to gervais Ford in ma, tech looked at it quickly out in the lot and said it was nothing to worry about but I could make an appointment if I would like to. Made an appointment the following week, had 2 tech's look at and they both said it was normal and not to worry about it. Well to my surprise at 37,000 miles 1,000 miles after the warranty has expired the engine fails. Took it back to gervais Ford and was told both head gaskets blew and it will cost me close to $2,000 to repair. Possibly more if any internal damage has been done. This is absolutely ridiculous on a vehicle that is new and the issue could have been possibly resolved earlier if that Ford dealer properly diagnosed the vehicle.
2003 Ford Mustang svt cobra. This is my second 2003 cobra (the first was involved in an accident). Both cobra's have and had problems with stalling, which causes a near complete loss of braking power (the brakes must have the engine running in order for them to work, unlike some vehicles), which is potentially extremely hazardous to my safety, as well as any other vehicle, pedestrian, children, or animal near me. It happens on deceleration at low speeds driving around town. There is a massive amount of documents going on that shows nearly 40% or more of 2003 cobra owners are having the same issues. Ford has updated the PCM 2 times already for the 2003 model year, and the problems still exist! Here is a link to a site with many owners reporting the problems: http://www.svtperformance.com/forums/showthread.php?s=&threadid=25697.
While driving my vehicle on the interstate I heard what I thought was a popping sound and then experienced a loss of power. I exited off the interstate and began driving again. My vehicle felt as if my torque converter was slipping and that power was reduced from the motor. I took my vehicle to my local service mechanic who advised me that the 3rd cylinder spark plug had somehow backed itself out of the cylinder head which was causing a loss of power to that cylinder. It also was still receiving power via the coil pack which in turn melted the rubber boot and fried the coil pack for that cylinder. The rubber from the boot ran down into the spark plug and filled the hole. I had to replace both the pug boot and coil pack for the 3rd cylinder along with the labor of removing melted rubber from the spark plug hole and cylinder head.
2003 Ford svt cobra new with 850 miles has stalled during deceleration eleven times to date causing a very dangerous situation since you have no engine power for acceleration, brakes or steering. I have just missed being in several accidents that could have been fatal to me and others. Ford svt keeps saying they have a PCM reflash and a TSB coming out in two weeks that will fix the problem. However, they have been indicating that for months and are obviously trying to avoid resolving the issue. There are many documented complaints on the svtperformance.com board in the terminator forum including mine in addition to calls to svt on their hotline @ [phone]. Please investigate this serious issue with Ford before someone is killed or seriously injured. Thank you.
NHTSA investigations
Spark plug ejection from cylinder head
On September 6, 2005, odi received a petition requesting that the agency investigate allegations of engine spark plug ejection in certain model year 1997 through 2004 Ford vehicles with triton v-8 and v-10 engines.odi received a total of 474 non-duplicative complaints on the subject vehicles where the complainant, or the dealer repairing the vehicle, reported that a spark plug detached from the cylinder and/or…
Engine complaints in other Mustang years
Frequently asked questions
How common are engine problems on the 2003 Ford Mustang?
NHTSA has 64 complaints about the engine & cooling of the 2003 Ford Mustang, 28% of the model year's 231 complaints. The component named most often is engine (35 mentions).
Is there a recall for 2003 Ford Mustang engine problems?
No. NHTSA lists no engine & cooling recall for the 2003 Ford Mustang, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2003 Ford Mustang engine problems start?
Half of the complaints with a recorded mileage happened before about 5,000 miles, and 71% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 1 injury to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.