2008 prius head gasket/cracked block common at higher millage?

289,000 miles.
Overheats after 15 minutes of driving. Drove it like this for 15000 miles. Been this way for two years. Exhaust gases in cooling system is main cause. Is this common at higher miles? If so which number cylinder usually goes out? I am going to try blue devil again but this time but with a spark plug removed one by one to let the sealer work better.

Problems so far fixed very cheaply

- Dash cluster went out : cheap amazon OBD hook up speedometer with temp gauge $40

- p0AA6 : toggle switch used every start to disconnect battery to reset codes so it can start again. $20

-P0420 $8.49 Red Silicone and a few resets down stream sensor Done in area where smog not required (Don't ask)

- burns 1qt every 600 miles 15w40-20w50 combined with used engine oil I have

I am squeezing every penny out this car. When the engine goes out I plan on a junkyard one later in future. I never had cars growing up and love this car. But I don't want to over spend. When the engine goes I will paint it get used engine and take care of it better. But that may be a few years later.

 

No not yet but I will probably try it. Thanks for recommendation

 

Wow! A coke bottle to the radiator? I have not herd about that one yet. I will feel guilty getting rid of the car as all parts for this car are dead cheap at the Pick A Part. Also I remember these two guys wanted to buy my Prius really bad. I explained to them that the frame is bent. I knew their scam to buy the car cheap and do Micky mouse job and sell it to a unsuspecting family while its in my name. It has happen to my family and I a few times. We bought junkers and got ripped off big time. I Sold my 2003 kia rio to pick a part as i did not want anyone to get hurt form a bent frame on that car. (it spins out in the rain). Anyway, My radiator gets filled with exhaust gases. I did notice that a couple of times my upper hose was suck flat. After bleeding the system using the bleeding screw, I was able to add more water and it has not happen since. Radiator cap went bad? The car was using coolant but I added blue devil, bars leak, k-seal at different times and it did stop. I did flush the system after each use and only have the k-seal in now. The radiator has over pressure from the exhaust gases causing overheating. Unplugging the fuel injector did not help as it had very low power and could not move out of its own way. My streets are 55 plus MPH. FML. No coolant leaves the expansion tank but the upper hose has a boat load of pressure. It is in fact able to hold the pressure for a entire day to the next. I figure by now the head is warped. May I mention I been putting used oil when it gets low in for over 2 years from my other car?? It burns 1 qt of oil or more as close as 500 miles in very hot weather. I still use fresh 20w50 every 5,000 miles. I don't really care for this engine as much as my other cars because I plan on putting a used one in later. What are some ideas you have? I am unsure if I should try the loose rad cap trick as the pressure gets so high it can blow off. I was thinking of making he bleeder screw loose so it can vent? I don't want to blow the motor if all the water comes out but if it can last 10 miles, awesome sauce. I just don't like putting in water everyday as these systems are a pain to bleed. I also unplugged the hot coolant storage tank. I am not sure if this is a good idea. I am debating if I should vent the rad every day before my trip. I use the car 1-3 times a day. By the time I make it to my 10 mile trip the light comes on and my aftermarket temp gauge is around 248-260F then I turn it off. I usually don't pull over when it gets hot as I am usually less than 5 minutes away.