Sometimes when I start the engine the start is difficult seems to have air bubbles in the fuel system, has a metalic sound for some seconds. I changed the EGR because of its broken cooler, the auxiliary water pump and the engine oil (Castrol 5w30 now and Shell before). On VCDS I have no DTCs but I'm not sure about some values:
052 Charge air pressure specified value 1053 hPa
053 Charge air pressure; actual value 951 hPa
143 Fuel high pressure; actual value 351500 hPa
147 Fuel Pressure Regulator Valve 16.41 %
184 Injection amount deviation cylinder 1 -0.52 mg/stroke
185 Injection amount deviation cylinder 2 0.79 mg/stroke
186 Injection amount deviation cylinder 3 -0.46 mg/stroke
187 Injection amount deviation cylinder 4 0.19 mg/stroke
218 Main injection; duration of activation 651.2 µs
219 Main injection; start of activation -2.09 °
220 Mean injection quantity 10.52 mg/stroke
The engine noise is the same everyday at first start but the fuel with air behavior appears once or twice per month.
052 Charge air pressure specified value 1053 hPa
053 Charge air pressure; actual value 951 hPa
143 Fuel high pressure; actual value 351500 hPa
147 Fuel Pressure Regulator Valve 16.41 %
184 Injection amount deviation cylinder 1 -0.52 mg/stroke
185 Injection amount deviation cylinder 2 0.79 mg/stroke
186 Injection amount deviation cylinder 3 -0.46 mg/stroke
187 Injection amount deviation cylinder 4 0.19 mg/stroke
218 Main injection; duration of activation 651.2 µs
219 Main injection; start of activation -2.09 °
220 Mean injection quantity 10.52 mg/stroke
The engine noise is the same everyday at first start but the fuel with air behavior appears once or twice per month.