2015 Ford Transit 250 was towed to our auto repair shop in Whitmore Lake, MI due to a loss of power, engine stall, and check engine light on while driving. The truck would start and idle smoothly, but as soon as it was put into gear or the engine accelerated, it coughed, shook, ran very rough, and quickly stalled.
Ford Transit check engine light problem repair caused by driving through a deep puddle on the highway. Diagnosed the problem, installed a new air filter, test-drove the vehicle, and confirmed the problem was fixed.
Would a wet air filter cause a rough running engine, engine stall, and Check Engine Light problem?
Yes. A wet air filter restricts airflow to the engine, causing a fuel delivery problem, rough running, and displaying a check engine light.
Diagnosis
Our Ford truck technician gave the vehicle a quick under-hood inspection and didn't notice any apparent problems. The truck started without issue and idled smoothly, but the Check Engine warning light was on. As soon as the vehicle was put into gear, it coughed and sputtered, ran very rough, and quickly stalled. It started again without hesitation and idled smoothly until the throttle was opened, and it immediately began sputtering, running rough, and stalled once again. The technician's first assumption was a fuel supply problem related to a plugged fuel filter or a failed fuel pump.
Next, the technician connected a scan tester and found an error code for a fuel delivery problem. This finding added weight to the technician's assumption the problem was fuel-related and that the diagnosis was correct.
Then they checked and found that the fuel pressure was good. This indicated that the fuel pump and fuel delivery were not the problem. The hunt for a reason for the problem just got complicated...
Next, the technician checked the mass air flow sensor readings, which were found to not be within specification when the throttle was snapped open. This meant the initial diagnostic assumption was not wrong, but the problem was due to an unexpected cause, like what often happens in diagnosis.
Next, the technician opened the intake air filter box and found the air filter to be completely soaked with water. The wet filter severely restricted airflow into the engine and upset the mass air flow sensor and fuel flow management. The engine was starving for air and fuel!
The wet air filter likely resulted from hitting a large puddle of water on the road and water being sucked into the air filter housing and choking the engine.
The air filter was removed, and the engine restarted. It performed normally without problems, and the check engine error codes were cleared and did not return.
The technician recommended cleaning and drying the air filter housing, replacing the air filter element, cleaning the mass air flow sensor, and avoiding big pot-holes full of water!
Repair
The mass air flow sensor was cleaned, the air filter housing was cleaned and dried, and a new air filter element was installed. The truck was road-tested, run, and driven with no power loss or check engine warning light. After the test drive, the engine computer was scanned, and no error codes were found. The technician did their final quality assurance inspection and reported that the vehicle was fixed and ready for return to the owner.
The customer was very relieved and very happy this was a simple, inexpensive repair!
FAQ
Can a wet air filter be dried out?
We do not advise drying an air filter that has been saturated with water. The water can cause the filter material to break down and disintegrate, allowing harmful dust to be drawn into and damage the engine.
Can water be drawn into the air cleaner and cause engine damage?
Not usually. If enough water reaches the air filter, the engine will quit running and prevent major damage. If the water is deep, it can flood the engine and get into the engine oil sump. When water mixes with engine oil, the engine bearings can be quickly damaged and require an engine replacement.
Tips
If you must drive through a large puddle, it is best to slow down as much as possible. Hitting a puddle at speed can cause the water to splash up and be sucked into the engine air intake and wet the air filter.
If your engine stalls from driving through a puddle, removing the wet air filter can sometimes get the engine running and allow you to drive to the closest auto repair shop. Running the engine without an air filter is not recommended, but it can be done briefly in an emergency. Avoid driving through water without an air filter.
It is recommended to replace an air filter that gets wet. The filter media can be damaged by the moisture and fail, allowing dust and dirt to enter the engine and cause damage.
If you have any Ford Transit service or repair needs, our Ford Truck specialist would be happy to help you.