Seeking Solutions for Overheating Issue and Check Engine Light on 2003 Fiat Idea

Hey there! I've had a similar issue with my 2001 Fiat Punto, just a different model, but pretty much in the same ballpark as yours. I'm not a professional mechanic, but I have a bit of a knack for car troubleshooting. Ended up finding out my woes were due to damage to the wiring harness. Took my Punto to my trusted local garage and after a while poking around under the hood, they got it sorted for me. The damage repair set me back about 110 Euro, but it was worth it, since it's been running smoothly ever since. Have you checked it out yet, or are you planning on doing it? What's the current mileage on your Idea? Any fixes or modifications done before this issue cropped up? Providing these details could help us dig deeper and help you better. Good luck!

Hey, thanks for the swift response! It's great to find someone who's dealt with a similar problem. My Fiat Idea has been clocking miles, it's at around 165139 km now. I got it serviced recently, but nothing major or special, just the regular stuff. I was thinking about getting it checked out soon based on the symptoms, and your experience gives me a bit more insight, so thanks! I didn't consider the wiring harness but will get it looked into now. Would also appreciate if anyone else has dealt with similar issues and can add something to this. Cheers!

Hey again, Handy to know your Fiat Idea's current mileage and service history, and cheers for the fast update. So, from my experience, your hunch about the coolant thermostat might very well hold some water given the symptoms you described. Remember, the thermostat's job is to regulate the flow of coolant depending on the engine temperature. So, if it's malfunctioning, your engine easily could run hotter than usual. And once the engine gets hot, it can turn on the check engine light as a response. When my Punto had a similar problem (plus the wiring harness issue), the diagnosis wasn't as straightforward as it could have been. The thermostat wasn’t completely broken, it was only partially opening, which made it really hard to pinpoint without the right testing gear. I'd suggest getting your thermostat checked, especially as it should be a cheaper fix compared to the wiring harness, running you around 30-60 Euro. Worth to check it than to risk overheating your engine seriously! Feel free to drop another comment if you need more of my two cents or experience. Good luck with your Fiat Idea and hope it gets back to its best really soon!

Really value your insight. I appreciate the thorough response and the explanation about the potential thermostat issue too. It definitely gives me a clear idea of what I need to be looking for and what to discuss with my mechanic. I am gonna move with getting my Fiat Idea looked at soon, prioritising that thermostat. Your input and experience has been massively helpful and I can't thank you enough for sharing. I'll drop a note here once I have some updates or if I need further suggestions. Again, cheers for the help! Until then!