Buying a 2009 Prius with 425k miles, still runs and drives well!

Yes, I got crazy and insane for buying a 425k miles Prius that has a "mysterious disappearing coolant issue" on both engine and inverter. Surprisingly this car still runs with no symptoms of head gasket issue. I'm sure it overheated several times and being a Toyota it will not blow up right away (I believe so!)

Will be investigating for the next few days on why the coolant is disappearing.

 

can the forum moderator fix the typo please, it should read 425k miles instead of 245k. Thanks.

 

$1,100 - seller has difficulty selling at her asking price due to her being honest about the condition of the car. Most of the seller will not disclose the issue until you found it yourself.

 

Found the sources of the leak and fixed them! Both engine and inverter cooling system has leaks.

The inverter side has a leak caused by a pinhole size in the radiator hose (near the clamp) This caused the inverter pump to loose coolant. Probably the weather in MO is just too cold not to trigger the code. The other leak was caused by a hack made by the original owner before selling it to the unsuspecting lady. The 3 way coolant valve failed and to provide heat during the winter it was bypassed using a coupler to connect the hose from the engine to the heater pump. The hose to the storage tank was also blocked using Harbor Freight hose clamps. The 3 way coolant valve wasn't sealed closed so it still leaks when under pressure (and the clamp is not enough to block the coolant completely under pressure) The only code showing up is P1116 which is the coolant storage blockage code which also points to the 3 way coolant valve (I guess the p1121 will follow soon)

Been driving the car around and so far no leaks and no signs of head gasket issue. Going to do some minor cosmetic fixes in the next few weeks.

If you think the Catalytic is toast at this mileage, it's just inefficient and that got a fix too (hack)

 

I noticed the hose from the pcv valve to the throttle body has some oil near the clamps, I believe oil instead of pure vapor is coming out from the pcv valve to the throttle body. I still have to open up the throttle body to determine if the blow-by is bad.

 

New Engine Code!

P2601 - Range/Performance of Coolant Pump Control Circuit

It turns out it's not the pump.

 

hoses are in excellent shape, the leak was caused by a bad mechanic not using the tool properly (punctured it)

It's been more than a week since the code was cleared and so far these are the 2 parts that commonly fail in high mileage prius and also are easy to fix if DIY.

 

it's been a while since I haven't post an update on my 425k miles 09 Prius. Yes it's racking up miles and keeping it. Doing some body work due to collision and will be painting soon. I have to check why there's no rubber grommet on the radiator post and fix the butchered install. Now I have less vibrations on the front end. Also the styrofoam bumper absorber is missing and without it the bumper cover is not flushed properly with the fenders, it will bow and detach itself. I bought the front bumper cover used for $25 with the styrofoam absorber and will definitely re-paint to match.
No check engine lights and no overheating and no leaks!

 

battery was replaced last year (reconditioned green tec)

I got the dreaded P0011 code which becomes permanent, as in clearing it with my scanner is next to impossible. It immediately goes back which means the OCV is bad. It was showing an intermittent P0012 before and tried removing and cleaning the solenoid only to have the codes returned again. I suspected that the solenoid although clicking when applied with 12v and using a bidirectional scanner is no longer operating correctly. I ordered a ROSTRA solenoid valve from RockAuto, it's a good brand which many uses for their transmission solenoid.

 

With the hot weather streak we have and with the car running flawlessly with the new vvt solenoid (OCV) It didn't take long for my 426k mile Prius to overheat and needing a head gasket (or a replacement engine)

Symptoms:
- Reservoir tank always fills up bubbling
- When left overnight to cool, the coolant from the reservoir tank doesn't go back to the radiator
- When opening the radiator after it has cooled overnight, coolant will gush out and spill over (combustion gases keeping up pressure)
- Head gasket test shows light green color when fully warmed up, my first test was it wasn't warm enough to detect combustion gases so I thought it was okay
- Coolant Pressure test can't maintain pressure, it's slowly goes down. Found air leaking at the bleeder nipple but when capped it's still not holding pressure.
- After the coolant pressure test, coolant drain out to the cylinder head and mixing with oil. Got a milk shake when I drained the oil (actually I saw this mixture on the dipstick)

Odd things about my small head gasket leak issue on Prius
- No misfire especially in the morning
- No white smoke coming out from the tail pipe
- It takes several trips before the overheating light turns on (RTOD) basically too much combustion gases are in the cooling system and most of the coolant spill out from the reservoir tank (note that coolant from reservoir tank doesn't return to the radiator)

I am planning on tearing up the cylinder head and replace the gasket.