I've been having some issues with my 2011 Prius with 98,000 miles on it. I was getting CEL and misfires in cylinders 1 & 4, if I recall correctly. Dealership wanted $900 to replace EGR pipe and and intake gasket. I thought that was BS and cleaned the EGR and EGR pipe myself. I also noticed that the coolant was low and filled it up. The CEL had gone off on its own before I even cleaned the EGR, but it was still misfiring. After cleaning and filling coolant, the misfires continued until I noticed I hadn't plugged back in the MAF sensor. After doing so everything seemed fine for about a month. I even took it on a 1000 mile road trip with no issues at all. Yesterday when I started up I got the dreaded "Check Hybrid System" and the misfires were happening again. Also, quite a bit of white, sweet smelling, smoke was coming out the exhaust. The coolant is low again and is brown. All signs seem to point to blown head gasket. God, I don't want to have to replace the engine. Anyone have any thoughts?
Bummer! Welcome to PC anyway. No doubt, it's the head gasket. Replacing the engine is probably the most straightforward way to fix it if you think it's worth fixing. Some have replaced head gaskets, though. However, you'd need to make sure the head isn't warped. @danlatu has a great write-up on his repair project. Blown Head gasket rebuild....@297k | PriusChat
People here have been saying to clean the EGR around 100K~150K, but it's all just guesswork. Maybe sooner is better, say 50K. It certainly sounds like failed head gasket. If you can consider DIY, maybe sending out the head to a machine shop, there is a gasket kit, includes head gasket. Part number is: 04111-37315 (per attached TSB-0169-16). Also attached, some relevant repair manual excerpts. This video has a lot of good tips: There's another recent thread here, on head gasket replacement, by member @The Critic: 2011 Prius Head Gasket Failure | PriusChat Thread by @The Critic on same subject, at Bob Is The Oil Guy (just stumbled on this, excellent pictures and description!: 2011 Prius Head Gasket Failure at 185k - Summary - Bob Is The Oil Guy
I feel the pain. Lots of blown HGs on these 3rd Gens. 98K miles is so early. Was the EGR super clogged back when you cleaned it? Had you noticed much oil consumption between changes?
Mine is well past that at 206K. No issues, but saying that is inviting disaster. Sort of like boasting about no flat tires. I'm providing data to the theory (of mine) that a Prius used mostly at highway speed doesn't accumulate as much carbon in the EGR circuit as in other city-driving stop-and-go uses. I'm getting around to the proof some day soon when I take a peek in one of those EGR pipes...
How fast is "highway speed"? Including long mountain uphills? My usage pattern is about half Interstate or equivalent at mostly modest speeds plus a lot of local hilly roads, with a lot of coasting down hills, which too often have stop signs at the bottom. I try to minimize very short trips. No symptoms so far. Still 55 to 70 mpg, depending on circumstances.
cleaning is not that hard, and new would be around $600, check on McGeorge Toyo site. I'd agree though: 80k miles is not premature. 50K would be my pref, plus the intake cleaning and OCC install.
Interstate highway speeds, 75-80 mph. That is about half of the commute, with speeds 45-55 and 65-70 mph elsewhere. Total distance one way is 70 miles. There is a 2200 foot elevation gain between home and work distributed over rolling hills. No steep ascents really. There are two merges where I'm pretty hot on the accelerator, which always worries me so I have been taking it easy lately. Especially the hot days. I'm going to take a look soon at the interior of my EGR circuit, see if I should really be worried.
