Avenger Diesel: Glow Plug System Warning Signs & Fixes

I had a similar issue with my 2012 Dodge Journey diesel last winter. Had limited experience with diesel engines before this, but learned quite a bit through this repair. The symptoms matched yours exactly, persistent preheating lamp, engine light on, and smoke under acceleration. After noticing these warning signs, I took it to my regular workshop. The diagnostic revealed a damaged cable connection to the glow plug heating element. The repair cost was 95€, which covered both diagnostics and fixing the faulty connection. The interesting part was that it wasnt the glow plug control unit itself causing trouble, just the wiring. Once they fixed the connection, all symptoms disappeared and the car has been running smoothly since. Before suggesting specific fixes though, could you share: How long has this been happening? Does the smoke appear more during cold starts? Have you noticed any changes in fuel consumption? Did you get any specific error codes from the engine light? This info would help narrow down if your issue is similar to what I experienced with my Journey or if its something else in the glow plug system that needs attention during your car maintenance visit.

Thanks for the input. These issues started about 2 weeks ago, and yes, the smoke is definitely worse during cold starts. The engine light scan showed error code P0670 which points to the glow plug control unit. My fuel consumption has increased by about 15% lately. The car had its last service 3 months ago at 68283 KM, and they didnt mention any issues with the diesel engine components at that time. The heating element system seemed fine then too. Based on your experience with the wiring, I will have them check the connections first before replacing the entire control unit. This seems like a smart first step in the diagnostic process. Makes sense to start with the simpler, less expensive fix. Will update once I get it checked out.

Thanks for providing those details. After dealing with similar symptoms on my Journey, the increased fuel consumption you mentioned actually rings a bell. In my case, the wiring fix alone didnt completely solve the problem, there was also carbon buildup affecting the heating element system. Your error code P0670 points more directly to the glow control unit than my situation did. Given that your diesel engine was serviced recently and the issue developed suddenly, this strengthens the case for a control unit problem rather than just wiring. The 15% fuel consumption increase is significant. When my car had this issue, I saw about a 10% increase before getting it fixed. The complete repair on my Journey ended up involving: Cleaning the heating element connections, Replacing the glow control unit, Basic car maintenance check of related components Total cost was around 380€, significantly more than just the wiring fix, but it resolved all symptoms including the smoke and engine light issues. The car also returned to normal fuel consumption levels. Would recommend having both the wiring and control unit checked, as these symptoms often indicate multiple related issues in the diesel engine system. Keep monitoring the fuel consumption, it can be a good indicator of whether the repair was successful.

Thanks to everyone who shared their experiences. After getting the car checked out today, I wanted to update on what was found and fixed. The diagnostic test confirmed both a faulty glow plug control module and damaged wiring to two of the glow plugs. The mechanic showed me where corrosion had affected the connections. Total repair included: Replacing the glow control unit, Repairing damaged wiring, Cleaning all glow plug connections, Full system check of the diesel engine Final cost was 425€, which included parts and labor. The engine light is now off, no more smoke during acceleration, and the preheating lamp works normally. Already noticed improved fuel economy on the drive home. The car maintenance technician mentioned doing regular checks of the glow plug system connections could help prevent similar issues in the future. Glad I asked here first, helped me understand what to expect and saved time in the diagnostic process.