Partner preheating lamp stays on

Sounds familiar! Is it struggling to start, especially when cold? Rough idling and startup smoke too, maybe?

Yeah, cold starts are rough, and the idling is all over the place until it warms up. Was it just the glow plugs? Anything else it could be?

Those were the exact symptoms. For me, it was the glow plugs. I wouldn't mess with it too much yourself unless you know what you're doing. Get it checked at a workshop.

Took it to the shop, and you were spot on. Glow plugs were bad. Cost 440€ to replace them, but it's running smoothly again. Thanks!