Volvo V70 diesel preheating lamp issue

Sounds familiar. I had similar symptoms on my V70 a while back - the constant preheating light is super annoying. Does it struggle to start, especially when cold? If so, it's almost certainly the glow plugs. Have you noticed any rough idling or engine misfires?

Thanks for the quick reply! Yeah, the cold starts are definitely rougher than usual. It cranks a bit longer, and there's a slight stumble for a few seconds after it finally fires up. Misfires, no, I haven't noticed anything specific. So you really think it's just glow plugs then? Any chance it could be something else related to the fuel system?

Based on my experience, that rough cold start is the giveaway. While other things could be contributing, the glow plugs are the most likely culprit with those symptoms. I'd suggest getting it checked at a workshop to confirm which one(s) are faulty. I ended up replacing all of mine when one went bad to avoid future headaches. It's probably best to get it sorted sooner rather than later to prevent any potential damage to the starter motor.

Okay, brilliant, I appreciate the insight! Glow plugs it is then. I'll book it in at the shop. Just had the quote through - 440€ including parts and labour. Ouch! Thanks again for your help – knowing it's probably 'just' the glow plugs makes me feel a lot better!