Seat Alhambra Diesel Preheating Lamp Issue

I also own a Seat Alhambra with a diesel engine, and I experienced a similar problem a while ago. The preheating lamp stayed on, and the check engine light illuminated. It sounds like you might indeed have a defective glow plug. A glow plug is an electrical resistance heater that warms the cylinders of a diesel engine to aid in cold starting. Have you noticed any decrease in fuel efficiency or a rough idle, especially during cold starts?

Yeah, since the preheating lamp issue, I've definitely noticed a drop in fuel efficiency, and the engine sounds like a bag of nails when I first start it in the morning. Was it a straightforward fix for you? Did you replace the glow plugs yourself, or did you take it to a mechanic?

Given the symptoms you described, it seems highly probable that the glow plugs are the culprit. Considering the complexity of accessing and replacing glow plugs in modern diesel engines and also the need for specialized tools, I would recommend taking your car to a qualified workshop. They can accurately diagnose the issue and replace the faulty glow plugs. It will ensure the correct parts are used and the repair is carried out safely and effectively. Ignoring it might lead to further engine problems and affect fuel efficiency. Good luck!

I just picked it up. You were spot on. All four glow plugs were shot. Replaced them, and the check engine light is gone. It cost me 440€, but at least it's running smooth again. No more rough idle on cold starts. Thanks again for your help!