Engine running unevenly in your Ford Puma

You can recognise an engine that does not run smoothly by vibrations, juddering and an unstable engine speed. In the Ford Puma with EcoBoost engine these complaints often occur between 2,500 and 3,000 revolutions per minute. The problem has various causes, from sensors to ignition components. Most issues can be solved. Early diagnosis prevents further damage.

Owners report various symptoms that indicate an unevenly running engine. The engine idles roughly, you feel juddering during acceleration and sometimes you lose power at higher speeds. These signals can occur separately or in combination.

‘ Checking the fuel system is a logical first step when you have complaints about engine behaviour. ’

Fuel injection as a cause

Problems with the fuel system often lead to juddering and hesitation. A contaminated fuel filter or clogged injectors disrupt the fuel supply. This results in uneven combustion and therefore an irregularly running engine.

In the Ford Puma this mainly occurs after a long period without replacing the filter. At certain moments the engine then receives too little fuel, which you will particularly notice during acceleration. Checking the fuel system is a logical first step when you have complaints about engine behaviour.

Contaminated fuel also has an impact. Small particles in the fuel block the fine nozzles of the injectors. This disrupts the injection pattern. As a result, combustion in the cylinders becomes uneven.

Spark plugs and ignition problems

Worn or defective spark plugs often cause the engine to run unevenly. The spark plug produces the spark that ignites the fuel mixture. Spark plugs that do not function properly result in poor combustion. There is then no optimal combustion.

In the Ford Puma EcoBoost engine, spark plugs wear out sooner than in conventional engines. The turbo creates high pressure and temperature. This puts more stress on the ignition components. Replace spark plugs according to the service schedule. If you have complaints, replace them earlier.

Symptoms of spark plug problems are:

• Difficult starting of the engine
• Loss of power at high engine speed
• Increased fuel consumption
• Uneven idling

Recognising turbo problems

The turbocharger forces more air into the cylinders. This increases engine power. Problems with the turbo lead to noticeably reduced power. The engine then runs unevenly. In the Ford Puma with 1.0 EcoBoost you notice turbo problems immediately. The turbo works continuously and is therefore sensitive to faults.

A leaking turbocharger or broken wastegate (a valve that controls turbo pressure) disrupts the build-up of pressure. You notice this when accelerating from low speeds. The engine responds sluggishly and jerkily. The engine delivers less power than normal.

Watch out for these signs of turbo problems:

• Whistling or hissing sound during acceleration
• Bluish-grey smoke from the exhaust
• Sudden loss of power
• Increased oil consumption

Check the oil level, for example every two weeks or before a long trip. The turbocharger is lubricated by engine oil and a shortage quickly leads to damage. Always use engine oil with the correct Ford specification.

‘ Reduced oil pressure leads to serious engine damage. ’

Loss of power with the EcoBoost

The 1.0 EcoBoost engine is known for its efficiency. The engine also has weak spots. Problems with the timing belt or oil pressure system often cause loss of power. This engine uses a timing belt that runs in oil. This is called a wet belt. The belt is continuously immersed in engine oil.

Contaminated engine oil clogs the oil strainer. Particles block the flow. This leads to reduced lubrication. As a result, the engine runs unevenly. Over time the tensioner of the timing belt loses tension. This directly affects engine performance.

Ford has carried out recalls for this problem. In a recall, the manufacturer calls cars back to the dealer to fix a known problem free of charge. Check whether your Ford Puma falls under these actions. Have the engine checked by an authorised dealer. Reduced oil pressure leads to serious engine damage. Address this immediately.

Faults caused by sensors

Modern engines use various sensors. These sensors measure, for example, the amount of air and the accelerator pedal position. The engine uses this information to perform well. A defective sensor disrupts the engine management (the system that controls the engine) and leads to an unevenly running engine. In the Ford Puma the throttle position sensor (accelerator pedal sensor) regularly causes problems.

This sensor measures the position of the accelerator pedal. The sensor sends signals to the engine ECU. The sensor sends incorrect information. The difference between what you ask for and what the engine delivers is then large. This results in juddering, hesitation and unpredictable behaviour.

The mass air flow sensor also sometimes causes problems. The mass air flow sensor measures the amount of air entering the engine. This sensor measures how much air the engine takes in. The sensor then determines the correct amount of fuel. A contaminated or defective mass air flow sensor disrupts the mixture composition.

Air filter and air supply

A clean air filter ensures that the engine performs well. The EcoBoost engine needs a lot of air for the turbo. A clogged air filter restricts the air supply. This leads to loss of power and uneven running. You will especially notice this at higher speeds.

Replace the air filter according to Ford’s service schedule. Do you often drive short journeys or in dusty conditions? Then replace the filter more frequently. A new air filter costs little. It solves many complaints.

‘ Only then do you start with a repair. ’

What repairs cost

The cost of repairing an unevenly running engine depends on the cause. Costs vary widely. Simple causes such as replacing spark plugs or filters cost between 100 and 200 euros. Replacing sensors costs between 150 and 500 euros. This depends on the type of sensor and labour time.

Turbo problems are more expensive. Overhauling or replacing the turbocharger can run into several thousand euros. Problems with the timing system fall into the same price range. Have this handled professionally by an experienced mechanic.

First have complaints investigated in a workshop. Many workshops read out the fault codes from the engine computer for a small fee. When reading out fault codes, the mechanic uses a diagnostic computer to check which faults the car has registered. This gives clarity about the cause. Only then do you start with a repair.

Regular servicing prevents problems

Servicing on time reduces the risk of problems with an unevenly running engine. Follow Ford’s service schedule. Replace oil, filters and spark plugs on time. This prevents common engine issues.

Check the oil level every two weeks. Also check the oil quality. The EcoBoost engine is sensitive to oil problems. The timing belt system requires clean oil. Always use engine oil with Ford specification WSS-M2C948-B.

Have software updates installed at the dealer. Through updates Ford sometimes resolves known problems with the engine management (the system that controls the engine). In a recall, the manufacturer calls cars back to fix a known problem free of charge. A visit to the dealer for updates solves complaints. No other measures are then needed.

When should you go to the workshop

Persistent complaints about uneven running? Then go straight to a workshop. Are warning lights illuminated or do you hear abnormal noises? Act quickly. Continuing to drive with a hesitating engine leads to consequential damage.

Has the engine suddenly lost power? Do you feel juddering while driving? Then have a professional diagnosis carried out. Some problems seem minor. They sometimes point to a more serious fault in the engine or turbo.

Look for a workshop with knowledge of Ford engines. The EcoBoost has specific characteristics. Not every mechanic knows this engine well. A proper diagnosis prevents unnecessary repairs. It also saves you money.

At Carnews you will find more information about Ford Puma problems and practical maintenance tips for your EcoBoost engine. Do you want to know what complaints other owners are reporting? Then take a look at our Ford Puma owner experiences and compare the known issues by model year.

Frequently asked questions

Which common causes can make a Ford Puma engine run ‘unevenly’?

Common causes of an unevenly running Ford Puma engine include a defective throttle position sensor (TPS) and problems with the oil pressure system, often due to the (wet) timing belt and tensioner, especially in the 1.0 EcoBoost engines. In addition, blockages caused by contaminated engine oil and wear or fouling of spark plugs, air filter and fuel filter can lead to unstable idling and juddering when accelerating. Faults in other position-determining sensors can also contribute to an erratic engine character and loss of power.

How can I myself trace the cause of my Ford Puma engine running ‘unevenly’ and which simple checks can I carry out?

You can start yourself by checking the basics: see whether the engine oil level is correct and the oil is clean, and whether the air and fuel filters are not clogged. Check the spark plugs for wear or fouling and replace them if necessary. Pay attention to whether the engine judders mainly when idling or around 2,500–3,000 rpm, and whether any warning lights appear on the dashboard. If the problem persists or you hear abnormal ticking or rattling noises, have the TPS sensor and the timing belt/oil pressure system checked by a garage.

Are there specific Ford Puma models or model years that suffer more often from an ‘unevenly’ running engine, and what are the ‘symptoms’ of this?

Ford Pumas with the 1.0 EcoBoost and MHEV engines (with wet timing belt) in particular are mentioned more often in complaints about unevenly running engines. Typical symptoms are an unstable idle speed, juddering when accelerating (especially around 2,500–3,000 rpm) and noticeable loss of power at higher revs. In addition, abnormal engine noises (for example ticking noises) and sometimes warning lights for engine or oil pressure are reported. These problems are often related to timing belt/oil pressure issues, ignition (spark plugs) and sensors such as the throttle position sensor.

What are the potential risks for the engine and safety if I continue driving with an ‘unevenly’ running Ford Puma engine, and when is professional help ‘unavoidable’?

Continuing to drive with an unevenly running Ford Puma engine can lead to reduced lubrication, increased wear, possible engine damage (especially with oil pressure or timing belt problems) and, in extreme cases, engine failure while driving, which endangers road safety. The risk increases significantly if the uneven running is accompanied by warning lights, abnormal ticking or rattling noises, noticeable power loss or oil pressure warnings. Professional help is unavoidable as soon as these signals occur or when the uneven running persists or worsens. In such cases you should stop driving immediately and have the car checked to prevent costly engine damage.