Peugeot 807 Overheating Bypass Valve

Whoa, overheating on an 807, that's nasty! I had something similar, though it wasn't exactly the bypass valve at first glance. Turned out to be a sneaky coolant leak messing with everything. Did you check the coolant level recently? That bypass valve might be getting cooked if the engine's running too hot. What readings are you getting?

Thanks for the quick reply. Coolant level looks okay on visual inspection, but could you give me more details on the coolant leak you had? Did it cause similar diagnostic errors related to the bypass valve? What specific readings would help diagnose this?

Visual inspection is a good start, but those leaks can be tiny. Mine was a hairline crack in a hose, losing coolant slowly. Yeah, it threw all sorts of random codes including the bypass valve thingy. Seriously, I'd get a pressure test done on the coolant system. It’ll find even the smallest leak. Otherwise, you'll be chasing shadows and probably doing more damage. Just a thought, probably worth going to the workshop!

Thanks for the advice about the coolant leak and the pressure test. I'll schedule a diagnostic assessment at a workshop. It was indeed a small leak, and it was fixed under warranty. Repair cost: 0€.