For a few weeks ive noticed the sound of liquid sloshing from engine area, behind dash, it does it whenever the engine starts from idle but doesnt do it while engine is running, only on the transition from idle to running internet searching doesnt seem to help with possible causes, although one possibility might be air in coolant system but i have no idea how to bleed the air out 2017 prius gen 4, 70k miles no other issues
This is likely an early sign of the 'heat exchanger' issue (coolant leak) - search this site for many threads. Check to see if you coolant is low. I ignored this warning sign and eventually my engine overheated due to lack of coolant. Sanctioned fix is to replace the catalytic converter, but it is possible to do a 'bypass'. You'll see in the many other threads. Since your mileage is low, I think Toyota will fix it no charge.
Checked under the hood and the Coolant tank was almost empty, way below the "low" line, Looks like im another victim of the 2017 Prius coolant leak then? I will refill and monitor for few weeks. Last service was November 2023 but I didnt check fluids after the service. Problem is, ive been taking my car to local independent garage for services and in UK Toyota only extend warranty past 5 years if you get it serviced at the main dealer. Watching youtube videos this repair costs £2000. I swear if this coolant leak turns out to be issue im facing and Toyota dont fix it I will sell and NEVER deal with Toyota again Im fed up of Toyota design flaws, last one being have the CAT on my gen 2 easily stolen.
