Hi forum, My 2015 prius 180k mile, last weekend had the water pump code, 261b, the temp shoot up, i stopped driving immediately and changed the water pump on this past Tuesday. After a few drive, the code went away on its own. But i obverse the coolant reservoir bubbling. which is concerning (headgasket?). The car does not overheat anymore. 1. the fan kick on at 203F if AC is off, if I use the AC, the fan is running when AC is on. 2. temp range 186 with AC on in maintenance mode. it is slightly higher if AC is off, range between 190s to 203 until the fan kicks on 3. sometime light white smoke in the back (bad sign). 4. the tube 16281 to 16264E are hot and will return coolant, that looks like it is from the engine/exhaust gas cooler. I will monitor my coolant level to see if it starts to drop. Any thoughts? What cause the water pump to go bad in the first place, just old? other issue cause over heat and ruin the pump over time? Thanks!
I also bought thermostat, my plan is to see if the coolant level drop first (headgasket), if it is the headgasket, i will send it to the shop could the thermostat cause the turbulence in coolant reservoir? i am fairly certain it is not suppose to be turbulence (not sure if it is bubbling) in coolant reservoir? perhaps it is early sign of the head gasket, not yet have any misfire code
There's lots of information on here about purging the air out of the system, which is likely the cause of things running a bit hot... I've no experience with that in Gen3 only in Gen2... Also don't worry about the inverter cooling system (turbulence in reservoir) because that system is separate from system you're working on and won't have air in it.
