Nissan Serena 2014 Experiencing Overheating and Check Engine Light Issues: Possible Faulty Engine Coolant Bypass Valve?

Hey, had this almost identical issue not too long ago with my 2011 Nissan Teana, logging at about 140,000 KM. Turned out, your hunch is spot on. It was indeed a problem with the coolant bypass valve cable connection. Not sure if it's a Nissan thing but it's definitely a possibility. The initial symptom was my engine heating up super quick, which I reckon is the same as yours now. At the garage, the mechanic explained that a faulty valve cable connection was impeding the normal flow of the coolants, leading to overheating. Fortunately, it wasn't something overly complex to resolve but obviously it became clear how it could lead to serious engine damage long-term. Got the mechanic to replace the faulty cable connection and checked the coolant bypass valve too, just to be safe. After the fix, it ran smoother, no more engine heating up or check engine light on. My advice? Don't wait too long before getting things done at the garage, in case of further damage. Anyway, fingers crossed it's an easy fix for you just like what I experienced! Best of luck, chum.

(Translated from German)

Hey there, your situation sounds strikingly similar to what went through. That being said, I'm pretty curious right now, do you remember roughly what the damage to your wallet was when you had to carry out those repairs? I've got a similar thing going on with my own Serena and it would be really helpful to have a rough esti on what I'd be up against at the garage. Also, has anything else come up ever since you got it fixed or has it been smooth sailing since then? You know how it is, one thing goes wrong and then it’s just a cascading series of unending issues. Hoping that’s not the case here though. Cheers for the help!

(Translated from German)

Hey there! I feel you, it's always handy to have an idea on expected expenses. So, for me, the cost to rectify the coolant bypass valve cable connection was about 155€. They diagnosed the issue, figured out the faulty part and did the repairs. Not too hefty if you ask me and it pretty much sorted the issue out. And you know what, since I got that repair done, it's been smooth sailing – my Nissan's running as cool as a cucumber, again. No other major issues have popped up after the mechanic fixed the coolant bypass valve malfunction. It just goes to show, sometimes it's well worth nipping these things in the bud. Hopefully it turns out to be just as straightforward for your Serena too. All the best with it!

(Translated from German)

Wait up guys! You just gave me some real peace of mind with your responses. Spot on, the symptoms are exactly like what you both described. I was dreading a sky high mechanic bill but 155€ doesn't sound too bad an investment to dodge potential engine troubles. I'll go ahead and get this sorted at the earliest, fingers crossed my ride sails through this as smoothly as yours did. And you're right, I don't want to be dealing with a cascading series of issues anytime soon, all the best to you too, let's hope our Serenas get back to their fully functioning glory soon. Thanks again guys! You've been a tremendous help.

(Translated from German)