Hey, good man, the whole thing sounds funny. I had a similar problem with my 2004 Opel Astra - so pretty similar to your rust bucket (just kidding ;-). I would describe myself as someone with some experience of cars, so not exactly an expert, but not a novice. I had the same problem with my auxiliary heating control unit back then, it was broken. They checked the whole thing at the garage and that was the culprit. The repair cost me 440 euros, a bit expensive, but what can you do, right? I would recommend that you go to a garage and check whether your control unit is faulty. If the problem persists, let's talk and maybe I can help you a little with my knowledge. Is there anything else you can tell us about it? A few more details could be helpful. Take it easy and don't let it get you down!

(Translated from German)

Hey dude, I had something similar with my old Vectra and in my case it was the water pump - it was gone. Had the same problem back then at around 133506 kilometers. I ended up having to have the radiator and thermostat replaced. That cost me about 150 euros. But before you change anything, have a specialist do it first. Given the mileage of your car, an inspection might not be a bad idea. Find out when the last service was. Because troubleshooting can still be a bit tricky. I hope I've been able to help you a bit, man!

(Translated from German)

Hey, I'm just looking at your post again. Interesting what you say about the water pump, person3! For me it was the ECU at the time, but you're right, it could be so many things. The Vectra isn't exactly the youngest car, and it's always good to have a specialist look at things like this - as you said. Sometimes we can be wrong in our assumptions. So, better get it checked out by a professional. The cost may vary, of course, but it's worth it considering how important the cooling system is to the car. And about the message error between the ECUs... could be, but could also be not. Get that checked by a professional too, okay? Better safe than sorry. I hope you get it all sorted out quickly. Let me know what happens to your old rust bucket (finally my chance for a joke ;-) )!

(Translated from German)

Hi guys, wow, thanks for all the tips and experiences you've shared! I really appreciate it a lot. The water pump thing, person3, that could actually be it. And person2, I will definitely have the ECU checked out. The message error between the ECUs sounds logical too, I'll definitely have that checked out. Yes, she's no longer a young lady, the good old Vectra. But I'll have an expert look over it and let you know what the results are. By the way, your old rust bucket jokes made me laugh! Stay healthy and thanks again!

(Translated from German)