bought a 2010 prius for my wife to use solely for work since she is a gig worker (doordash grubhub etc). when we got it in may 2024 from carvana it had 83k miles on it. now it has 143k miles solely from her jobs. since we owned it i have done oil changes every 5k miles for safety sake ( which means once a month since she drives about 200 miles a day), put new tires on, new brakes all around, replaced the 12v battery, and also just after the 4th of July this year, replaced the hybrid battery. Sad bit of story now. Two weeks after the battery was replaced, my wife called me saying that the engine was making a horrible rattling noise. Thinking that it was possibly the spark plugs, I was able to carefully nurse the car home and changed the plugs that night. However, the rattle still was there. Took it to a shop to diagnose it, and they claimed that the egr cooler was clogged and caused the head gasket to blow. Quoted 8k to repair. Not having that much, my wife asked her fellow drivers friend that has a shop about it and he said it would be easier to just put a new engine in for 2k. He also claimed that the intake had a huge puddle of oil just after the throttle body and that is what really killed the engine and not the head gasket. After being at the shop for two weeks, on our anniversary of 7/30, the job was done and her car is back in our hands. He took me to the back and I did actually see the large puddle of oil inside the manifold, so at least that part was true. The first shop didn't provide me with any proof that it was the head gasket that blew on the old engine. I talked to the shop owner and he said since the engine would go to the scrap yard, I could take anything I wanted off. I immediately grabbed the egr cooler assembly so we would have a spare and have been starting to clean it. I plan on now every other oil change or maybe two or three to just pull off the egr cooler and swap it out for the clean one. I also plan on cleaning out any oil that may end up in the intake at each oil change. Is there anything else I can do to prevent another engine failure? Seeing that we have spent a few grand already even before the engine, I would like to try and stay on top of things better. Any and all advice is appreciated.
$2000 for another engine, installed is a crazy good price. Especially if a shop did it. If you can strip the engine, go and do it. Take the injectors, plugs, coils, water pump, take it all Hopefully this engine you put in is a low mileage JDM engine. I would say just continue doing what you're doing, oil changes and simple maintenance. It hopefully will last you another 100k miles or more. The problem with your old engine is most likely a head gasket issue. The oil accumulation in the intake doesn't seem like it's too unusual, maybe you can install an oil catch can?
Where did the replacement engine come from? US sourced salvage? Rebuilt? JDM? It was the head gasket, it's way too common. Oil in the manifold is also common, some improve a poor pcv design by installing an oil catch can. A catch can must be carefully monitored in a gen3 that burns oil so that engine oil seals are not blown out. The egr did not blow the head gasket - it is simply a flawed engine that really did not get better until the 2016 gen4 engine redesign. Some have replaced their gen3 engine with a gen4 powerplant. Some have installed a frankengine, gen4 bottom end and head with gen3 egr and intake. Hybrid Pit now sells a gen4 bottom end with a gen3 head and intake. Others go with a JDM used in Japan motor, a low cost option, many with good results. JDM distributors are in most big cities. Probably the best outcomes come from a professionally rebuilt engine which includes revised pistons, rings, intake and egr valve. Hybrid Pit sells those as well. A revised egr valve and the latest ecu software was suggested in a European tsb to mitigate head gasket fails. It was recommended for US vehicles as well without the hg promise. Coolant changes every 30-50k along with 5k oil changes is my formula. Monitor the coolant temperature in realtime with a lower audible alarm than 248f. The ecu or combination meter only flashes the temperature light briefly at 248f and is often ignored. Never drive after an overheat warning is observed. However most hg fails occur on engines that never overheated and are starting to happen on low mile engines with clean egrs as the engines age. There are advocates of preemptive water pump changes and egr cleanings. If it makes you feel good... Other major expenses are likely in a 200 miles a day gen3 Prius work vehicle. The best plan for an important work transport is to sell it and buy a gen4 Prius or Rav4 or move to a conventional Civic, Camry or Corolla that fits your budget.
I got tongue lashing on here for checking dipstick level weekly, but changing egr cooler every other 2 or 3 oil changes?
You'll go round and round with this until you get tired of it and then you won't like most things in life . This is not a fun model for sure . Unless it's real old people driving very little and don't have that faculties to remember anyway. You see tons of these parked out in front of retirement homes if you notice .
