- Engine runs rough or dies at idle.
- Engine vibrates
- Lack of power
- Poor throttle response
- Smoke from the exhaust
Diagnose Check Engine Light
To fix the problem, you must first identify the fault code that triggered the 'check engine' light.
Every time a check engine light goes on, a specific Diagnostic Trouble Codes is stored in the memory. However, access to these codes is possible using an OBD-II scanner.
These devices range from something simple as a Bluetooth OBD adapter that connects to an application on your smartphone over dedicated hand-held scan tools to powerful diagnostic tools.
These instructions work on 2000 and newer Lancia models, including:
- Nuova Delta
- Loose gas cap: A loose, damaged, or missing gas cap can trigger the check engine light.
- Mass airflow sensor: The MAF sensor is used to determine the mass flow rate of air entering a fuel-injected internal combustion engine. The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine.
- Oxygen Sensor: O2 sensor is mounted in the exhaust manifold to monitor how much-unburned oxygen is in the exhaust as the exhaust exits the engine.
- Timing Chain: Most newer gasoline engines have Variable Valve Timing, which is extremely sensitive to timing issues. If the 'check engine light is accompanied by a lack of power, rough idle, and stalling, timing should be first on the list to check. The problem is usually with a chain tensioner, which is not long enough to compensate for slack in the timing chain. As this can be a prelude to a much more dangerous timing failure, check this without delay.
- Crankshaft Position Sensor: The crankshaft position sensor is quite a common failure point on many Lancia models. It will usually cause an intermittent misfire, engine cutting out, or not starting occasionally. In some cases, it can trigger various timing or alternator-related codes. Although being very sporadic in the beginning, symptoms will happen more frequently as time goes by.
- Turbo Issues: Turbocharged engines can suffer from various boost-related issues. Usual causes are broken hoses, a dirty air filter, or a blocked intercooler. It is also possible for a turbocharger wastegate to be stuck open. Lastly, the boost sensor can be defective, giving false readings. You might experience a lack of power and acceleration accompanied by whining or hissing noises from the engine area, smoke from the exhaust, and high fuel consumption.
- PWM Controllers: Unlike older cars, which had simple cooling fan regulation, newer ones use pulse width modulation (PWM) controllers. A module that controls the fan speed can get damaged by moisture and corrosion, resulting in dead cooling fans. Although this will not affect engine performance, it can still cause overheating.
- Proportional Valve: Diesel engines have a common rail injection system, where an electronic proportional valve controls the fuel pressure. If it starts failing, you might experience a loss of power, hard starting when cold and black smoke from the exhaust. In addition to the regulator with an integrated sensor, check the wiring and connectors for damage.
- Intake Swirl Flaps Another quite common and potentially very dangerous problem on JTD engines is intake swirl flaps. They control the intake geometry by opening and closing. With time, carbon buildup can obstruct the movement, sending the engine into 'limp mode.' More importantly, flaps can even break off and fly into the engine, causing catastrophic damage.
Flashing check engine light
While the solid check engine light can be caused by various things, one that is flashing on and off is a clear and definite sign of engine misfire.
This can be caused either by faulty sparks, broken coils, or leaking fuel injectors. Whatever the cause, the misfire can quickly damage a catalytic converter and other engine components.
Try easing off the throttle, as this usually helps. If not, stop the car at the first possible spot. Never ignore a check engine light that is going on and off intermittently.
An OBD-II scanner can help you determine why the check engine light is flashing.