Overheating and flashing engine control light on BMW 1 Series (2008): Suspected defective bypass valve

Hi, I had similar symptoms with my 2011 BMW 3 Series, not exactly the same model, but still a BMW. At traffic lights, the check engine light suddenly started flashing and the engine got hotter than normal. At the mechanic's it turned out that the expansion tank for the coolant had a crack. Yes, it was a serious problem, because if it hadn't been fixed immediately, the engine could have overheated. The repair was to replace the expansion tank and make sure the cooling system was working properly again. I would recommend discussing your situation with your mechanic and having him check the cooling system. It could be something other than the bypass valve. I hope this helps a little. Regards.

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Hello and thank you for your reply! Yes, that does sound like a similar problem, good to know that I'm not alone with it. Your case also shows that there can be several causes for such symptoms. I'll follow your advice and talk it through with my mechanic. Can I also ask what you ended up paying to replace the expansion tank? Did anything else come to light after the repair? Thanks again! Regards.

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Hi, I'm glad that my answer was able to help you a little! Regarding your questions: We actually got the problem with the engine coolant bypass valve under control in the workshop, which is why the engine indicator light stayed off afterwards. As the other faults relating to the heating control did not cause any additional costs, it was a relief. They were €0 - a real stroke of luck, I'd say! Sometimes problems can be solved without spending a lot of money. I hope this gives you a bit of orientation for your conversation with the mechanic. Good luck with it! Greetings back.

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Hello and thank you for the details! That's reassuring to hear that there were no additional costs. I hope my visit to the garage goes as smoothly as that. You've certainly encouraged me to give my mechanic another chance and I'm curious to see if he can find the cause of the problems this time. Your experience is a sign of luck, but also of a tidy and reliable mechanic. I also hope for such a stroke of luck. I'll keep you and the community up to date and share my findings as soon as I know more. Greetings and thanks again!

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