2012 Prius - The Good Ol' P0301 Gremlin!!!

Yup, I have a grease pen mark in green to stand out against the reddish coolant and not a black Sharpie marker which can be mistaken as dirt or grease.

Indeed I do.

 

LoLoL! Yeah. Pretty far along with the repair. At this point, I've done all the recommended repair and maintenance to the EGR system . Only thing left to do is get the firmware updated at Toyota. I've been contacted for a recall, so when I take it it, will have them take care of the firmware then.

I plan to keep the car for a while (fingers crossed), long enough to see how the Cybertruck pans out. Thinking of getting a Prolong Deluxe Reconditioning kit as a matter of fact. Seeing as they are in San Jose, I can just pick up and save a little on shipping.

 

I change oil every 5k miles. I use Pennzoil Ultra Platinum and stock up on it when ever I can find it on sale (I bought into the natural gas thing a while ago with my other vehicles). Or I use a good full synthetic like Mobil1. I always make sure alerts are set at Slickdeals.net when there are front page postings for oil.

I don't have any problems with excessive oil consumption. I think I mentioned earlier my oil was low. But forgot that when I checked it, failed to realize my car is parked on my driveway which is on a steep incline. So when the CEL first appeared, first thing I did was to check oil, found it was low and was shocked. Then went to drain the pan and expected to see no oil come out. But tons (or a regular amount) came pouring out. That was then that I realized the reading was off because I was on an incline. That set me off on this whole intake/EGR/OCC project with the '12.

I think I am good now. Will do some final tweaks with cooland and the coolant tank and run the '12 through this winter and report back if the P0301 gremlin ever makes a re-appearance.

 

Crap. Turned on the car today and got the death rattle for a brief second. Shut her down and popped the hood. Coolant dropped a bit. Opened up the OCC and a few ounces of fluid poured out. Definitely have a HG leak. Good news, Gasket Masters is less than 4 miles away from my house. Bad news, HG repair is always a gamble.

Will give them a call and have them come out and do the job onsite.

 

Might just do the head gasket job myself. Doesn't look so tough and I have all the tools including impact tools. Also, I would prefer to have an OEM head gasket over the aftermarket Fel Pro head gasket that Gasket Masters uses. Also, noticed in watching their videos, they don't keep the rockers in sequence, which bugs me. Of course, I would save some money at the expense of my time. But I have time off in December and should be able to knock it out.

Will need to clear some garage space, but I am pretty sure I can do this. I've replaced a HG on my Ford truck before. Any tips from any that have tackled HG repair as a DIY'er?

 

Once again Mendel, my friend, friend of all Prius owners, you are the OG of the Prius Chat forums!

I am thinking eBay is a good place to buy the parts? Do forum members know of a better place for genuine Toyota OEM parts?

 

Is there a procedural list for replacing the head gasket on the Gen 3's? Something like this which I used for my Ford truck?

If not, I'll put one together in Excel based upon the available videos. Each step shall be numbered then a user can resort in descending order so you can work backwards in reverse.

 

I have the Haynes manual too. It is pretty hazy on steps. But it does have torque specs.

Putting together the steps now into Excel.

 

Here is what I got so far. Will finish it later. Time for some food.

Step Procedure
1 Jack up car. Remove passenger side front wheel
2 Remove harmonic balancer
3 Remove wiper assembly
4 Drain coolant
5 Remove airbox
6 Remove AC line bracket
7 Remove grounding straps and ignition coils
8 Remove 3 sensors from behind ICE (O2, Crank position, Oil pressure)
9 Remove ignition coil clips
10 Remove water pump connections
11 Remove AC compressor connections
12 Remove knock sensor connection
13 Remove throttle body sensor connection
14 Remove fuel injector clips
15 Remove cam position sensors
16 Remove ground wires attaching harness
17 Remove purge connector
18 Remove MAP sensor
19 Remove #10 bolt from harness
20 Remove last to connectors (EGR and one above EGR)
21 Fold harness over to the driver side of the car
22 Remove EGR Valve
23 Remove EGR Pipe
24 Remove hoses and bracket near EGR system
25 Remove hose connecting from engine to throttle body
26 Remove intake manifold, disconnecting PCV hose from intake
27 Disconnect coolant hose from ICE
28 Remove valve cover bolts and pry up valve cover
29 Remove motor mount Part 1: Start with 14mm from underside first using deep socket and flex head ratchet
30 Remove motor mount Part 2: Remove five 17mm fasteners from top side of motor mount (NOTE: Engine will drop slightly)
31 Remove motor mount Part 3: Remove 8th stud
32 Remove motor mount Part 4: Remove 3 14mm bolts from side of ICE and remove motor mount bracket
33 Remove remove spark plugs and discard them
34 Remove water pump with #12 gear wrench. 4 bolts can be removed from the upper side. 1 bolt can be removed through the wheel well
35 Drain oil
36 Remove harmonic balancer
37 Replace crank bolt to allow motor to be spun to TDC
38 Set timing to TDC. Long mark that touches chain to the 2 o'clock position
39 Lock in timing postion part 1: Remove 1st cam shaft assembly (the one closest to passenger side)
40 Lock in timing postion part 2: Fold shop towels into 3rds and place over cam
41 Lock in timing postion part 3: Replace cam shaft assembly and snug up only the darker 10mm bolts. Timing is now locked in
42 Remove timing cover bolts 4x 14mm, 15x 12mm all around, & 10mm in middle of timing cover
43 Remove timing tensioner 2x 10mm
44 Remove oil filter housing, ensuring oil pan is in place to catch leaking oil
45 Remove crank bolt
46 Set timing chain tensionor
47 Remove 12mm bolt fasting oil dip stick. Push dip stick out of the way towards driver side
48 Remove thermostat housing 3x 10mm bolts
49 Remove exhaust shroud 3x 10mm bolts
50 Pry off timing cover
51 Remove timing swing arm
52 Remove timing chain guide 2x 12mm bolts
53 Remove timing chain guide
54 Remove timing chain
55 Unfasten 12mm bolts off valve train, leaving them in position (do not remove black 10mm bolts)
56 Pry up valve train to loosen from head. Punch down with hands on vale train to break silicon, then remove valve train
57 Remove 16x roller rockers, keeping them in exact order. (Tip: use empty egg carton to keep them in proper order)
58 Ensure valve stem caps are not dislodged and are in place as roller rockers and valve train is removed before proceeding
59 Remove exhaust nuts from cylinder head 5x 14mm
60 Disconnect fuel line, leaving fuel injectors and fuel rail in place
61 Remove 10x head bolts (size 12 triple square) in 4 passes starting from outside-to-inside and using an X-patterned as you work towards center (1st pass: break, 2nd pass: break further, 3rd pass: break until bolts can be loosened by hand, 4th pass: use power tools to completely remove.
62 Ensure head bolt washers are removed and not dislodged into the engine as head bolts are removed. Be sure to discard head bolts as they cannot be reused
63 Pry off cylinder head and remove cylinder head
64 Remove failed head gasket
65 Clean mating surfaces cylinder head
66 Check cylinder head for warpage
67 Clean mating surfaces on ICE
68 Clean mating surfaces on timing assembly
69 Clean mating surfaces on timing cover
70 Replace 3x O-rings in timing assembly
71 Put new head gasket into place
72 Replace the cylinder head
73 Torque into place cylnder head bolts starting from center, working outwards in a criss-cross x-pattern. Torque specs are 36lbs, then 1/4 turn, finally 1/8th turn
74 Ensure cylinder head mating surfaces are clean once again. Apply maximum heat resistance RTV is applied to 3 sides of cylinder head. Do not apply RTV to passenger side of cylinder head
75 Re-install exhaust bolts onto studs
76 Replace roller rockers, ensuring they are in the proper straight position
77 Re-instal valve train/cam shaft assembly, ensuring assembly is properly aligned as it is being lowered down to mating surfaces
78 Apply high temp RTV to timing cover, ensuring an extra amount is applied to the area where the head and block meet. Add extra amount of RTV to the engine side of the mating surface where the head and the block meet as well
79 Replace timing tensionor gasket
80 Re-install timing chain, ensuring proper timing positioning
81 Re-install timing swing arm guide, pressing it into place firmly
82 Re-install timing cover
83 Re-install timing chain tensionor
84 Remove first cam shaft
85 Over to the EGR area, re-install hoses and bracket assembly
86 Re-install EGR
87 Re-install thermostat housing
88 Re-install water pump
89 Re-install oil pump filter assembly, replacing o-rings and cleaning mating surfaces before re-installation
90 Re-install oil dip stick tube fastener
91 Re-install intake manifold, ensuring PCV hose or hose to OCC (if you have an oil catch can installed) is re-installed in doing so
92 Re-install valve cover, ensuring O-rings are replaced during re-installation

 

The parts arrived. I was so pleased at how well the parts were packaged. Wow!

I'll knock this out after Christmas. Will spend some time today doing a lay-mechanic's menial-type tasks to prep for the job:

• Labeling baggies for nuts/bolts
• Labeling wires with tape
• Labeling parts with grease pens
• Capturing all torque specs and committing them to memory
  
• Ensuring I have enough brake clean
• Ensuring I have enough shop towels
• Ensuring I have all my batteries charged for impact tools
• Ensuring I have the proper replacement fluids
• Ensuring I have the proper RTV
• Ensuring I have the one specialty tool needed (No. 12 Triplesquare for the head bolts) which I don't already have
• Making sure I have the space organized for all the parts that I'll remove
  • Including folding tables and such
• Thinking through what other jobs I should perform while everything is apart
  • For instance, removing the oil pan as I am sure there is sludge in there now that won't come out with a simple drain
  • Replace tranny and inverter fluid since the under panel has to come out anyway

I've watched pretty much all the videos out there on Gen 3 HG repair. There are bits and pieces to be learned from all of them. The pro's do the job in about 3 hours. I am thinking it will take me at least 2x-3x as long.