Hi all, I have seen lots of threads about losing coolant from the inverter pump/lines/reservoir. However, I have been having an issue of slowly losing coolant from both my engine and inverter reservoirs... Is there anywhere that these two systems meet? Or are they 100% separate? If I knew the point at which they converged, I feel that it would also be the source of my leak... I top off about an inch in each reservoir everyday I drive. It does not leak heavily enough that I have been able to look/shine light into the engine compartment and see an obvious drip/stream coming from a particular location. Thanks so much for any help! Nick
Hey Nick, welcome to the forum! The only place the two systems meet is that the radiator, and I'm pretty confident the cores are separate even though they share the same radiator. Do you have any external drips?
After the car has been running for some time, I can see that there is some coolant pooled up on the plastic underneath the radiator, but I can't see/locate a steady drip. Perhaps the radiator itself has a leak right where the two systems meet? Also, thank you! Long time lurker, first time poster.
Welcome to Prius Chat . The systems are separate. Is there any visible signs of leakage or puddle underneath the car? Where are you adding the engine coolant: the overflow reservoir or the radiator? Any recent damage to your Prius? Good luck and keep us posted .
Sounds like you found the likely culprit! Just out of curiosity, what's the year and mileage of the offending Prius? Also, has the coolant ever been changed? Love your username, by the way.
2007 prius with 150k on it. New hybrid battery at 130k, and other than that it has never had any real issues! No recent damage to prius that I know of.... although my wife is the primary daily driver (beginning to wonder if she had a run-in with a bad pothole or something...) Water pump looks clean. I believe I have been adding coolant to the overflow reservoir for the ICE. I don't have the tools at my disposal to lift the car up or do a pressure test on the system. So I guess the next stop for me is the mech. shop! Is it safe to have them pressure test the inverter coolant system as you would the ICE coolant? Love how helpful and knowledgeable everyone is here, thanks a bunch!
Go borrow a cooling system pressure tester from your local parts store. Pressurize the systems and your leak(S) will show themselves. I would suggest you have at least two leaks but the cooling system pressure tester will confirm or deny this. Don't overheat your ICE that ally head and cast iron block do not tolerate high temperatures very well.
This sounds most plausible. It's an odd coincidence that both circuits are losing coolant, and the one place they're at least very close together is at the front, their two radiators. Either an accident, or rocks kicked up by a car in front of you, something managed to damage both radiators?
I’m not sure the inverter circuit is pressurized??? If it is I don’t think a pressure testing kit would have that type of cap.
Skibob you may be right on the inverter side. But it certainly would work on the ICE side maybe he gets lucky and finds a common leak to both systems do not know.
Don't bother adding water to the ENGINE coolant reservoir you have to add water directly to the rad. The rad is probably empty. Take the black plastic cover off the top of the rad. There's like 5 screws. You have to get your finger behind the screw and push it out as you unscrew the screw. Take cover off with car cool open the rad cap fill to the top. Put the cover back on but don't bother with the screws the hood captures it when its closed. Screws been missing on my 07 for 8 years. I like to be able to check the read level. Cover loose its fast and easy. Inverter coolant leak is pretty rare. Engine coolant leak fairly common as the water pump wears out. No where do those loops meet each other. Completely separate. They each have there own compartment in the rad. Top one is the engine with the rad cap. The small bottom one is the inverter that's serviced by the Inverter reservoir that's sits on the left side of the inverter.
