Another blown head gasket.

Haven't been around the forum for a while but my 2010 with 150k miles probably has head gasket issue.

It started 10k miles ago with overnight start misfiring in cylinder 2 & 4. Did the usual moving around spark plugs, coil packs, clean intake manifold & TB, clean injectors, EGR pipe(not the cooler which seems ok), etc. The misfires comes and go after each trouble shoot but cannot pin point anything. Finally, cylinder 1 & 2 consistently misfiring after stopping the hot engine after an hour or so. Also observed coolant loss in the reservoir. Since then I removed the coolant reservoir cap o-ring so that there is no pressure in cooling system and the misfire went away for several day of start/stop. So that pretty much point me to coolant leaking into cylinder when engine is stopped and pressure in the cooling system. I'll order the head gasket, bolts, seals etc. and go about replacing it. This is another big disappointment with my Prius after $2500+ master cylinder issue not covered under recall/warranty.

Seems like 2010 are dropping like files with head gasket problem?

 

I thought about doing cyl leak down and/or bore scope but I'm pretty certain it's head gasket at this point.

Do you have a link handy for reporting? I'll check Toyota web site later in the evening.

I looked at the EGR pipe and peeked inside the cooler but it's quite clean and didn't feel like doing it at the time. I'll clean the EGR parts when I pull the head.

Thanks.

 

My memory is not as good anymore. Maybe I was looking at the pipe.

 

I got the parts delivered today from RockAuto. Got the head gasket kit and head bolts. Seems like the head gasket kit is quite complete and made in Japan like it was mentioned in another thread. Attached is the pic of the list of items included in the head gasket kit if anyone is wondering. I'll work on the car in about a month since I need to paint the house first.

 

The master cylinder wasn't covered since it was not throwing code when the brake/ABS recall was done and Toyota corporate denied me even though dealer head mechanic and service advisor agreed it should have been covered. I just bought a master cylinder from 2011 on ebay and replaced it myself for $250.

Yeah, bought a 2017 Volt and after I fix the Prius it'll be a backup car and give it to my daughter when she start driving next year or maybe she'll get the Volt and I get back driving Prius.

I was sick and need to finish some home projects before the rain so this head gasket thing is on back burner. I don't see anything abnormal on dipstick/oil or the exhaust pipe. I'm not sure if i want to spend any more money to get leakdown test kit. I may look in the cylinder with borescope when I have some time before pulling the head to see if there is coolant when cooling system is pressurized since the only time I get misfire is when starting the car after it sitting after driving. Thanks.

 

Thanks Amos. I have Torque app on my phone for several years now and monitor various temperatures/paramters. My water temp stays pretty constant 195F throughout the years. I don't see any noticeable variations before and now. I also have techstream and do not see any pending code or anomalies. Unless I have EGT probe for each exhaust port, water temp doesn't tell me much in my case. Thanks.