Alfa 159 Glow Plug System Failure Warning Signs

Had a very similar issue with my Alfa 156 2.0 JTDm from 2008. Speaking from moderate experience with diesel engine problems, the symptoms you describe match exactly what I encountered. The diagnostic test revealed a faulty connection between the glow plug control unit and the wiring harness. During cold start conditions, this caused irregular preheating cycles and the constant warning lights. The excessive smoke during acceleration was directly linked to incomplete combustion due to improper preheating. The workshop found corroded connectors at the glow plug harness, which required cleaning and partial replacement. The total repair cost was 95 Euro, which included the diagnostic test and fixing the cable connections. The good news is that its a relatively straightforward fix, but I would not recommend continuing to drive without addressing it. Poor preheating can lead to increased engine wear and potential damage to the fuel injection system over time. Could you share: Current mileage, How long have these symptoms been present, Whether you notice any starting issues in cold weather, If the check engine light shows any specific error codes This information would help determine if your case is similar or if there might be additional underlying issues with the car maintenance requirements.

Last service was at 85000km so quite recent. The symptoms started appearing about 2 weeks ago. The heating element in the glow plugs seems inconsistent, especially during cold starts. Vehicle stalling occurred twice last week. Just checked the error codes using a basic scanner and got P0380, definitely pointing to the glow plug circuit. The starting issues are more noticeable when temperatures drop below 10C. Worth mentioning there is no starting issue when the engine is warm, which further suggests its glow plug related rather than a fuel system problem. Will get it checked soon since the symptoms are getting worse and I dont want to risk further diesel engine damage.

Thanks for providing those details. After dealing with my similar Alfa 156 issue, seeing your error code P0380 really confirms my initial suspicion about the glow control unit being the primary culprit. When my car had these symptoms, I noticed the exact same pattern, no issues with warm starts but problematic cold starts. The engine misfire and stalling you mentioned matches what I experienced, especially when the heating element system wasnt functioning correctly. The control unit on mine eventually failed completely, causing constant engine light warnings and severe starting issues. Your recent service history suggests its likely not a maintenance-related problem, similar to my case where the glow plug control unit failed despite regular servicing. Based on my repair experience, you should factor in these potential costs: Control unit replacement: 220 Euro, Labor costs: 120 Euro, Diagnostic confirmation: 45 Euro Since youre already experiencing stalling, Id strongly recommend getting it fixed within the next week. In my case, waiting too long led to additional stress on the diesel engine starting components. The increasing frequency of your symptoms matches how mine progressed. When the stalling started happening with my car, it quickly went from occasional to frequent within a matter of days.

Thanks for all the detailed responses and sharing your similar experiences. The progression of symptoms you described with your Alfa 156 matches what I am seeing. After reading about your repair experience, I will schedule a workshop visit this week rather than risk further issues. The diagnostic test results with the P0380 code combined with the cold weather starting problems and stalling make it clear this needs immediate attention. The total repair cost estimate of around 385 Euro for the control unit replacement and labor seems reasonable given the complexity of the heating element system. I appreciate the warning about potential additional diesel engine damage if left unaddressed. Will book it in tomorrow and make sure they do a complete glow plug system check including the wiring harness connections you mentioned. Better to fix it now than risk more expensive repairs later. Thanks again for helping confirm my suspicions about the glow control unit being the likely culprit.