If you drain all the coolant through the stopcock on the radiator with a hose attached before you break all that open, it's much neater. You don't get coolant splashing everywhere and especially down the dipstick hole if you have that removed. You don't want coolant in your oil!
I'm next week replacing both waterpump and thermostat, as a preventative job. No problems yet, but my Toyota hybrid is 10 years old with 230k km's (about 160k miles) and after changing these components I can go another 10 years. Also cleaning intakemanifold, EGR-valve and EGR-cooler next week. Quite a job for an amateur, but it's worth doing it, saving myself lots of money.
Great video, my Prius had the exact same problem with the thermostat going bad. Same issue, under 50 in town no overheating, over 50 on the freeway it was overheating.
Knowing the water pump and thermostat give issues I just recommend replacing them as a preventative measure. Somewhere between 150-200k miles before overheating and destroying your head gasket and getting stranded. If at 150-200k miles you replace them and the car makes it double I would say you saved money.
@@readtherealanthonyfaucibyr6444 usually stuck shut as the engine will run hot and blow the head gasket. But I’ve heard of both happening. The water pumps just fail with little warning but you get a check engine light. Both are easy to replace/DIY.
@@RobertBeedle Gotcha thanks, I hope they're not prone to sticking shut. I drove a car for years that had that problem and you constantly had to watch the temp gauge and be ready to stop. It would happen intermittently as the thermostat would start to go bad. Sometimes would close for 10 seconds and then open back up. My next car was one where the thermostat was prone to getting stuck open only which was such a relief. It got stuck open and I didn't even care, still haven't replaced it.
@@readtherealanthonyfaucibyr6444 usually people experience issues with them well after 100k miles. So I would just replace every 100k-150k and flush the coolant. Should never have an issue. Oh and buy OEM
Good stuff, thanks! Mine is over 200K miles driven so I´m thinking of changing the water pump already in advance only basing on mileage. Might as well change that thermostat on the same go...
If your losing coolant it is simple and very common on the Prius, you have blown the head gasket. Try Steel Seal or Blue devil. Remove the thermostat after installing the correct amount run the car for about an hour with the heater on full blast. Replace with a new thermostat and most often this will get you to the next 150 K buy then you should have saved enough in gas to buy a new one. Peace, thermostats do not cause you to lose fluid, leaks and blown head gaskets do.
If the thermostat goes bad it doesn’t expand or open to allow coolant to flow properly and what happens is when you put your prius into maintenance mode the coolant will overflow out of the reservoir and cause you to lose coolant through the overflow. I know because this happened to mine. I replaced the thermostat and the water pump for extra measure and she’s been running fine ever since over 250k miles and still going! Good luck to others encountering this similar issue of coolant loss.
@@Cambodimerican24 I have same issues with my Prius. I have a 2011. Changed out engine, water pump, sensor and thermostat. I have issue when I drive high speeds 70-80 mph up hill. Reservoir hot but not boiling like before. Temp red light would turn on or flash and then when I slow down it will eventually turn off. My mechanic replaced literally everything minus the radiator and the inverter coolant pump. Can anyone please help???? No codes or no check engine lights just the red light engine temperature turns on when driving high speeds up hill for long periods of time. Is the issue temp sensor on EGR pipes? My mechanic has replaced with all OEM parts. Any advice?
Question: same symptoms. If the thermostat is bad, will coolant boil out and cause level to drop? Thought I had a leak, now thinking it is the thermostat.
Initially pointing to the part, rather than flashing a light on several parts and exclaiming, “There it is!” would be more clear. When expressing what you’re doing, pretend you’re explaining it to a sixteen year old female. That should work.
My 2012 Prius plugin has 285k miles. I just replaced the water pump. Cost $200 at Longo Toyota ordering online. Really easy to replace. Solved my overheating problem. Now I I have a feeling the head gasket is next to go. So I bought that one for $50. Longo Toyota rocks.
Thank you for making this video and providing the details along the way. I now know what I'm up against. Did replacing the thermostat fix the overheating issue?
The $1500 electric air conditioning compressor can be destroyed if coolant gets in the AC compressor's connector and leaks down into the non-replaceable internal circuit board. Happened to me when a clueless mechanic replaced my Prius' water pump without taping off or sealing the connector after disconnecting the electric cables before draining the coolant.
HELP, please. Problem is sporadic random overheating, accompanied with coolant liquid blown out tru the release valve on the plastic overflow container. I installed new thermostat (ebay), new water pump (the old one looks ok, and the rotor does not appear to be damaged) pressure test was good, keeps 12 psi for long time, exhaust fumes in coolant is negative, I pumped many many many times, the liquid remains blue... Any information will be greatly appreciated.
Man... Removing that thermostat was a b...ch.😄 Actually, it is best to replace the Water pump as well while you doing it. It is best to replace them as a preventative measure after 150K, which I did not do on my 2010 Prius,(which I regret now), now it overheated couple of times at 218K, I received a code for Water pump. My water pump failed. I have to replace them both now, and see if I have to do a head gasket now...
I have same issues with my Prius. I have a 2011. Changed out engine, water pump, sensor and thermostat. I have issue when I drive high speeds 70-80 mph up hill. Reservoir hot but not boiling like before. Temp red light would turn on or flash and then when I slow down it will eventually turn off. My mechanic replaced literally everything minus the radiator and the inverter coolant pump. Can anyone please help???? No codes or no check engine lights just the red light engine temperature turns on when driving high speeds up hill for long periods of time. Is the issue temp sensor on EGR pipes? My mechanic has replaced with all OEM parts. Any advice?
I think mine is getting stuck, it will run fine for days, weeks sometimes, and mostly when I have the AC on, it will overheat for no reason, highway, street, and then it flows out the coolant tank, then I'll refill it, and it'll be fine for whenever it feels like doing it, I replaced the water pump because I was getting a code, and it would loose complete power, I replaced the water pump, and now it does that.
What actually was happening with your car? I’m getting heat light on and flashes when I turn heat on. It scared me. My remedy is to turn the AC on at 73f. Car works fine with NO heat light flashing. What could be the problem? I’m going to try release the air pockets first.
@@Greg-re7tr Good to know. I got dirt cheap the windshield washer pump and inverter pump from a Gen2 ata self serve salvage yard to play with this summer. Actually, more for a garden tractor homebrew spray bar attachment pump to see which works adequate. Didn't realize there were recalls regarding.
One other thing young buck, they have cordless ratchets that have more torque than the air ones why are you still carrying around that old school tool? Oh and forgive me, someone said lost coolant it why I said you do not lose coolant from a thermostat. I listened to you and you said overheating, yeah that could be 3 things, a bad fan clutch, water pump, or thermostat not opening for water flow. LOL
Video is too short for a big job and mostly seeing you and ring spanner crying and fighting for a long time with a couple nuts. I wanted to get a good peek at the faulty thermostat because I needed to find exact spare and also wanted to see the condition it was in.
If you drain all the coolant through the stopcock on the radiator with a hose attached before you break all that open, it's much neater. You don't get coolant splashing everywhere and especially down the dipstick hole if you have that removed. You don't want coolant in your oil!
I love all the coolant going allover the motor and electrical connections.
me too! 😍
I'm next week replacing both waterpump and thermostat, as a preventative job. No problems yet, but my Toyota hybrid is 10 years old with 230k km's (about 160k miles) and after changing these components I can go another 10 years. Also cleaning intakemanifold, EGR-valve and EGR-cooler next week. Quite a job for an amateur, but it's worth doing it, saving myself lots of money.
How's your Prius doing now?
Great video, my Prius had the exact same problem with the thermostat going bad. Same issue, under 50 in town no overheating, over 50 on the freeway it was overheating.
At how many miles?
The dipstick was removed and then the heater hose flooded the area with antifreeze. Hope the oil was changed.
Was thinking of the same thing!
Thannk you for this helpful video :)
Knowing the water pump and thermostat give issues I just recommend replacing them as a preventative measure. Somewhere between 150-200k miles before overheating and destroying your head gasket and getting stranded. If at 150-200k miles you replace them and the car makes it double I would say you saved money.
So the thermostats get stuck closed, or do some get stuck open?
@@readtherealanthonyfaucibyr6444 usually stuck shut as the engine will run hot and blow the head gasket. But I’ve heard of both happening. The water pumps just fail with little warning but you get a check engine light. Both are easy to replace/DIY.
@@RobertBeedle Gotcha thanks, I hope they're not prone to sticking shut. I drove a car for years that had that problem and you constantly had to watch the temp gauge and be ready to stop. It would happen intermittently as the thermostat would start to go bad. Sometimes would close for 10 seconds and then open back up. My next car was one where the thermostat was prone to getting stuck open only which was such a relief. It got stuck open and I didn't even care, still haven't replaced it.
@@readtherealanthonyfaucibyr6444 usually people experience issues with them well after 100k miles. So I would just replace every 100k-150k and flush the coolant. Should never have an issue. Oh and buy OEM
What are systoms thermostat fail? My prius red temp light blinks couple times only on freeway driving. I turn on heater but no heat at all.
Good stuff, thanks! Mine is over 200K miles driven so I´m thinking of changing the water pump already in advance only basing on mileage. Might as well change that thermostat on the same go...
Please answer the question “did that fix your problem of loosing fluid only at freeway speeds
Thanks brother.
From Paris, France.
Thank you for the video of the process how to change the thermostat 👍🏼✌🏼
If your losing coolant it is simple and very common on the Prius, you have blown the head gasket. Try Steel Seal or Blue devil. Remove the thermostat after installing the correct amount run the car for about an hour with the heater on full blast. Replace with a new thermostat and most often this will get you to the next 150 K buy then you should have saved enough in gas to buy a new one. Peace, thermostats do not cause you to lose fluid, leaks and blown head gaskets do.
Except that the thermostat housing is known to crack on these, which will totally cause loss of coolant.
@@KalebMarshallDulcimerPlayer How you know it's the head gasket? The engine will rattle loudly when you first start up!
If the thermostat goes bad it doesn’t expand or open to allow coolant to flow properly and what happens is when you put your prius into maintenance mode the coolant will overflow out of the reservoir and cause you to lose coolant through the overflow. I know because this happened to mine. I replaced the thermostat and the water pump for extra measure and she’s been running fine ever since over 250k miles and still going! Good luck to others encountering this similar issue of coolant loss.
@@Cambodimerican24 I have same issues with my Prius. I have a 2011. Changed out engine, water pump, sensor and thermostat. I have issue when I drive high speeds 70-80 mph up hill. Reservoir hot but not boiling like before. Temp red light would turn on or flash and then when I slow down it will eventually turn off. My mechanic replaced literally everything minus the radiator and the inverter coolant pump. Can anyone please help????
No codes or no check engine lights just the red light engine temperature turns on when driving high speeds up hill for long periods of time.
Is the issue temp sensor on EGR pipes?
My mechanic has replaced with all OEM parts. Any advice?
Question: same symptoms. If the thermostat is bad, will coolant boil out and cause level to drop? Thought I had a leak, now thinking it is the thermostat.
Yes
Good idea taking the dipstick out that way the coolant can go right in the oil
Initially pointing to the part, rather than flashing a light on several parts and exclaiming, “There it is!” would be more clear. When expressing what you’re doing, pretend you’re explaining it to a sixteen year old female. That should work.
thank you sigma man 5 yo ago. You are awesome
Thank you, this saves us a lot of $$$ by doing it ourselves!
Should I unplug battery first
You could at least tell people whether it fixed the problem or not... That is why we watched the video! Just saying...
My 2012 Prius plugin has 285k miles. I just replaced the water pump. Cost $200 at Longo Toyota ordering online. Really easy to replace. Solved my overheating problem. Now I I have a feeling the head gasket is next to go. So I bought that one for $50. Longo Toyota rocks.
I have 2012 Prius V, when you ready to do the head gasket work let me know, maybe we do both in a same time. I hope you are in South East.
Thank you for making this video and providing the details along the way. I now know what I'm up against. Did replacing the thermostat fix the overheating issue?
Which Prius are you working on? Super important!
The $1500 electric air conditioning compressor can be destroyed if coolant gets in the AC compressor's connector and leaks down into the non-replaceable internal circuit board. Happened to me when a clueless mechanic replaced my Prius' water pump without taping off or sealing the connector after disconnecting the electric cables before draining the coolant.
What are systoms thermostat fail? My prius red temp light blinks couple times only on freeway driving. I turn on heater but no heat at all.
HELP, please. Problem is sporadic random overheating, accompanied with coolant liquid blown out tru the release valve on the plastic overflow container. I installed new thermostat (ebay), new water pump (the old one looks ok, and the rotor does not appear to be damaged) pressure test was good, keeps 12 psi for long time, exhaust fumes in coolant is negative, I pumped many many many times, the liquid remains blue...
Any information will be greatly appreciated.
Man... Removing that thermostat was a b...ch.😄 Actually, it is best to replace the Water pump as well while you doing it. It is best to replace them as a preventative measure after 150K, which I did not do on my 2010 Prius,(which I regret now), now it overheated couple of times at 218K, I received a code for Water pump. My water pump failed. I have to replace them both now, and see if I have to do a head gasket now...
I don’t understand the air pockets and bleeding. Just turning the heater in high will remove all the air pockets?
Hi
Typically, how long it takes
To reach normal temp.?
Tks
after removing the intakemanifold, it's a lot easyer to acces the third bolt
I have same issues with my Prius. I have a 2011. Changed out engine, water pump, sensor and thermostat. I have issue when I drive high speeds 70-80 mph up hill. Reservoir hot but not boiling like before. Temp red light would turn on or flash and then when I slow down it will eventually turn off. My mechanic replaced literally everything minus the radiator and the inverter coolant pump. Can anyone please help????
No codes or no check engine lights just the red light engine temperature turns on when driving high speeds up hill for long periods of time.
Is the issue temp sensor on EGR pipes?
My mechanic has replaced with all OEM parts. Any advice?
Did you solve the problem brother my has got same problem this one showing key sign temp one
The last bolt that took your dad a lot longer......hidden way in the back......was that a nut or a bolt and what size socket. thank you
2 nuts and a bolt and 10mm socket only. (Mostly Prius socket sizes are 8mm, 10mm, 12mm, 14mm. 17mm, 19mm, and 22mm).
@@MrLopez87 Appreciation, boss man
Thank you Sir
It seems it missing lots of information, even what wrench (tools) to use. This was removed but never was mentioned.
Tank you brother
What code were u getting before replacing it?
Thanks for the video, what ended up being the problem? Bad thermostat or sediment?
Did it work? My Prius Gen3 is having the same symptoms
please everyone.. do NOT drain your coolant like that.. HAHAHAHAH
For me it was impossible to remove 3rd hidden screw in the rear. How did you ever remove that
I used a flexible socket on mine. It’s like 8 inches long and it bends like a spring. Was easy for me. But it’s definitely a pain with regular tools.
My 2013 Prius is doing excactly the same thing
Only mines heats up in the mornings after like 15 minutes in the freeway after 65 miles
Hi,what a wrench size to remowe it? Thx
YOU MISSED TORQUE SPECS AND TOOLS NEEDED
ALSO MISSED PUTTING THE CAR INTO MAINTENANCE MODE
Did you get the torque setting? There are 2 bolts and 1 stud, which may have different torques
I came to this video to see the seating of the thermostat and spring specifically and it's the one thing you don't show.
I think mine is getting stuck, it will run fine for days, weeks sometimes, and mostly when I have the AC on, it will overheat for no reason, highway, street, and then it flows out the coolant tank, then I'll refill it, and it'll be fine for whenever it feels like doing it, I replaced the water pump because I was getting a code, and it would loose complete power, I replaced the water pump, and now it does that.
What actually was happening with your car?
I’m getting heat light on and flashes when I turn heat on. It scared me. My remedy is to turn the AC on at 73f. Car works fine with NO heat light flashing.
What could be the problem?
I’m going to try release the air pockets first.
Was that the problem??????
Hi, was the thermostat the problem?
Is it easy to open what tools I need
You will ruin the ac compressor if coolant gets in the connector and you reconnect it like that.
It most likely the bad electronic water pump. This generation Prius was prone to having bad electronic water pump.
I thought that was 2nd gen from 2004-2007. They had a recall on the inverter pump.
@@Greg-re7tr Good to know. I got dirt cheap the windshield washer pump and inverter pump from a Gen2 ata self serve salvage yard to play with this summer. Actually, more for a garden tractor homebrew spray bar attachment pump to see which works adequate. Didn't realize there were recalls regarding.
I mean, after +250K miles, you would expect things to fail :))
One other thing young buck, they have cordless ratchets that have more torque than the air ones why are you still carrying around that old school tool? Oh and forgive me, someone said lost coolant it why I said you do not lose coolant from a thermostat. I listened to you and you said overheating, yeah that could be 3 things, a bad fan clutch, water pump, or thermostat not opening for water flow. LOL
Any update?
Video is too short for a big job and mostly seeing you and ring spanner crying and fighting for a long time with a couple nuts. I wanted to get a good peek at the faulty thermostat because I needed to find exact spare and also wanted to see the condition it was in.
this light is too strong, cant see very well. you need a light difuser, to give you uniform light with no reflections and no shadows.
hi