Ford Mustang Problems

Wrench Light Illuminated
The 2017-2022 Ford Mustang’s optional 10R80 10-speed automatic transmission has had many manufacturer communications through the NHTSA Portal. While not as urgent as a true recall, a NHTSA manufacturer communication, can give us insight into what problems a vehicle is presently having, long before the manufacturer decides to file a recall notice. The Ford 10R80 Transmission has been known to frequently throw a wrench indicator light which corresponds to a powertrain malfunction, and shift erratically. The most common causes of transmission failure are discussed below.

PCM Failure:
The Powertrain Control Module (PCM) is essentially your vehicle’s brain. It communicates between the engine, transmission, and other critical systems of your vehicle. When a PCM begins failing, it may send DTC codes, causing your wrench light to come on. Normally, a PCM will fail due to excessive heat, excessive vibrations, or software incompatibility. A failed PCM may prevent the car from starting, or the car may start but will not go into gear. A failed PCM may also cause your exhaust to smell like unburnt fuel. If your car is not starting, or will start but will not go into gear, please bring it to the dealership immediately for warranty repair work, because a faulty PCM will eventually cause the transmission to fail as well.

TCM Failure:
The Transmission Control Module (TCM) is a computer that is designed to calculate the correct time to shift your transmission into a different gear. A TCM can fail due to excessive heat, or incorrect voltage. When a TCM begins to fail, it will throw trouble codes causing the wrench light or other dashboard lights to come on. Other signs of a bad TCM are harsh shifting, delayed shifting, or failure to go into gear. A transmission that won’t shift is an extremely dangerous situation. If you feel your car hesitating to shift or not shift at all, please bring it to the dealership for warranty repairs immediately.

Transmission Valve Body Rebuild:
If your Ford Mustang has the optional automatic transmission, then this extremely complicated part may fail. A transmission valve body is an aluminum plate with maze-like channels, that work with solenoids to control the transmission’s shifting. Because your Mustang’s automatic transmission has 10 forward gears, there is an amazing level of complexity involved to get your transmission to shift into the correct gear properly. Many Mustang owners have complained of erratic shifting, poor shifting, missed shifts, and high engine revs with no upshift. Bad shifting, with or without a dashboard light coming on may be symptoms of a failing valve body, or one of the solenoids attached to the valve body. This condition is extremely dangerous, so please bring it to the dealership for warranty repairs immediately.

Engine Runs Hot / Overheats
The Ford 2.3 Liter Eco-Boost engine has a long history of running hot, and overheating. Several recalls have been issued over the years, concerning their improper installation, or the need for additional heat shields. This excessive heat from under the hood can cause failure to brake cables, fuel lines, fuel tanks, and other wiring near the source of the heat. Also, as your Mustang’s Eco-Boost engine is turbocharged, the compressed air exiting the turbocharger is hot. Ford has equipped your Eco-Boost motor with an intercooler to help lower these temperatures, but customers still complain of high temperatures under the hood, and overheating. If your wrench light, or high temperature light is illuminated, please bring your vehicle to the dealership immediately for warranty repair work. Do not wait for the problem to degrade the engine further.

Carbon Build Up:
In order to deliver high performance, while keeping fuel mileage as high as possible, your Ford Mustang is equipped with a direct-injection engine. While all direct injection engines are generally more efficient, because the gasoline does not travel through the intake valve like an ordinary internal-combustion engine, a small amount of oil may run down the sides of the valve, unmixed with the gasoline which can cause oil buildup. Over time, due to the heat of an engine, that oil will bake on the valve, and turn into carbon buildup. This problem will only get worse over time, preventing the intake valve from closing properly, and carbon will eventually fall into the cylinder and damage piston rings. If your check engine light comes on, or your fuel mileage is consistently lower than when you bought the vehicle, please bring your Mustang to the dealership for warranty repairs.

Head Gasket Failure:
Some clients are informing us that their head gasket has failed. A head gasket is a gasket between the cylinder block and the head of the engine, preventing fluids from leaking out of the engine, and preventing fluids from mixing inside the engine. Either one will eventually cause the engine to fail. Excessive engine heat and carbon build-up will eventually cause the head gasket to warp and fail. If you see fluids collecting in your engine compartment, or underneath your Ford Mustang, you may have a failed head gasket. Anytime you see fluids leaking from your car, please bring it to the dealership immediately. This is not normal. Modern cars do not leak fluids.

Piston Failure:
It is not uncommon for Ford Mustangs to have piston failure. If the issues above, such as carbon buildup, and excessive engine heat are not addressed early enough, your engine’s pistons will eventually become damaged, and cause the engine to fail. While this repair may be covered under your warranty, because of supply chain interruptions, this breakdown could cause your vehicle to be in the dealership for over 30 days. Please contact The California Lemon Law Group to find out if you are entitled to a lemon law buyback.