Head Gasket Repair? 2005 Prius 250,000 Miles

Hello fellow Prius Lovers,

I have a 2005 Prius with almost 250,000 miles. I purchased the car about 10 years ago when it had 130,000 miles. The check engine light came on about a week ago with the car starting rough, but running fine. I've been needing to top off my oil pretty often the past year but all of the other fluids were fine. I took it to our mechanic who diagnosed the engine as misfiring on three, and said I needed a full head gasket repair. They did not pull the spark plugs as they had been replaced about 20,000 miles ago. The mechanic asked if the coolant was always getting low, which it was not. The quote is $1,900 which is more then the car is worth.

I took the car to get checked out at the Toyota dealership where I had the car serviced regularly before it became too old and expensive. They pulled the spark plugs which are corroded and full of oil. This is consistent with needing to top off the oil more then was normal the past year or so. They recommended the replacing valve cover gasket, plugs and performing EFI service at quoted $700. The dealership said the valve cover leaking is causing the oil to get into the spark plugs and cause the misfire. They also said they rarely see Priuses needing a full head gasket repair, and when they do typically the engine is misfiring on one and not three.

My plan is to take the car back to my main mechanic and have them perform the work the dealership said would fix this issue. Has anyone seen similar issues with their high milage Priuses?