VW Touran 2.0 TDI Uzun seyahat sonrası sabah geç çalışma

Merhaba Arkadaşlar,

Aracım 2009 VW Touran 2.0 TDİ . 

Arac 1 saat yol giderse ertesi gün uzun uzun marş yapsam da motor çalışmıyor. 5 10 dakikalık seyahatlerde ertesi gün hafif zorlansa da ama çalışıyor. Bir kere çalıştıktan sonra kapatsam da sorunsuz çalışıyor.

Gidişinde çekişinde rölantisinde sorun yok. Ustalar sorunu bulamadi. 9 aydır sorun devam ediyor.

Mars dinamosu temizlendi kömürler değişti, akü değişti, mazot filtresi değişti, yakit hortumları değişti, yakıt hattina check vana takıldı, Enjektörler degisti, her yer kontrol edildi.

Sanki bir şekilde silindire yağ veya yakıt doluyor ya da hava yapıyor ama neden kısa seyahat değil de uzun seyahat sonrası sabah böyle yapıyor olabilir. Arıza kodu vermiyor.

Kızdırma bujilerine bakıldı mı kızdırma bujilerinin hatları dahi kontrol edilsin bence.

Evet bakıldı. Sağol.

İngilizce bir siteye sorunu yazdım, şu cevap geldi.

Biraz yapay zeka cevabı formatında ama işe yarayabilir...

It sounds like your 2009 VW Touran 2.0 TDI is experiencing an issue that could be related to fuel delivery, engine timing, or a component that behaves differently under heat after longer journeys. Since your technicians have already replaced and checked many parts, it's important to consider some additional possible causes for this issue:

1. Fuel Leaks or Vapor Lock

• Even though you replaced the fuel hoses and installed a check valve, it's possible that there's still an issue with fuel delivery. Fuel vapor lock could occur when fuel vaporizes in the fuel line, preventing proper fuel flow. When you travel long distances, the fuel system could heat up enough to cause fuel vaporization. After the engine cools down, the vapor lock could release, allowing the car to start again. This could explain the difficulty starting after long journeys.

2. Glow Plugs or Glow Plug Relay Issues

• Diesel engines rely on glow plugs to assist with starting, particularly in colder conditions. If the glow plugs or the glow plug relay are not functioning correctly, it may cause starting issues, especially after the engine has been hot. Glow plugs are used to preheat the air in the combustion chamber, and if they aren't functioning as they should, it might make it harder to start the engine after long trips when the engine is hot.

3. Crankshaft or Camshaft Position Sensor

• A failing crankshaft or camshaft position sensor might cause intermittent starting problems. These sensors tell the engine control unit (ECU) the exact position of the crankshaft and camshaft, which is vital for proper engine timing. If one of these sensors is malfunctioning, the engine may struggle to start or fail to start altogether, particularly when hot. These faults often don’t always trigger fault codes, making them harder to detect.

4. Fuel Injectors or Injector Timing

• Even though the injectors were changed, there might still be an issue with the timing or fuel pressure at the injectors. If the injectors are leaking or not properly atomizing the fuel, the combustion chamber may become flooded with fuel, especially after a long drive when the engine has heated up. Once the engine cools down, it could start more easily because the excess fuel has evaporated or been cleared.

5. High-Pressure Fuel Pump or Fuel Pressure Relief Valve

• The high-pressure fuel pump might be functioning intermittently. If the fuel pressure drops too much when the engine is hot, it may cause difficulty starting. The fuel pressure relief valve could also be faulty, affecting the fuel pressure in the system, leading to hard starts after a long trip.

6. Starter Motor or Electrical Issue

• Even though the starter motor was cleaned and checked, it might still have an issue that only manifests when the engine is hot. Heat soak could affect the starter's electrical components, making it struggle to engage when the engine is warm but functioning fine once it cools down. There could also be an issue with the wiring or relay associated with the starter motor that’s sensitive to temperature.

7. Compression Issues

• If there are any compression issues, such as worn piston rings or valve seals, they might not be noticeable during short trips but could become a problem when the engine is hot. When the engine cools down, the seals might expand slightly, allowing for easier starting, but when hot, they could allow fuel or oil to seep into the combustion chamber, making it hard to start.

Diagnostic Tips:

• Fuel System Pressure Test: Have a fuel pressure test conducted to check if the fuel system is maintaining proper pressure, especially during hot conditions.
• Temperature Sensors: Check the coolant and intake temperature sensors. If these sensors are giving incorrect readings, they could affect starting behavior, particularly when the engine is hot.
• Live Data from ECU: Even though there are no fault codes, accessing live data from the ECU during a hot start condition might reveal irregularities in fuel pressure, timing, or sensor readings that could point to the underlying cause.

Summary:

Your issue is likely related to fuel delivery, engine timing, or heat-related sensor issues. The fact that it occurs mainly after long trips and when the engine is hot suggests a component that behaves differently under heat, potentially causing flooding of fuel or oil into the cylinders. I would suggest checking the fuel system pressure, the high-pressure fuel pump, and engine sensors that might not throw codes but could still cause intermittent problems.

Sağlam enjektörler takıldı ama sorun düzelmedi. İlginç olan bilgisayara bağlanınca her zaman 2 no'lu silindire fazla yakıt gittiği görülüyor. Enjektör yeri değişse de bu durum değişmiyor.