2011 Prius Valve Cover Photos

[nthach]

Originally Posted by krismoriah72
Heres a little blog of a garage that mostly works on Prius taxis.

"In short, we are highly familiar with the patterns of Prius taxi repair. Transaxles failing from every angle, HV batteries down to the last electron. Engine side, we regularly see blown head gaskets and oil consumption up to 1 quart per day. Combination meters, warning lights, wiring trouble of any flavor. Double salvage vehicles. Every trouble code in the book. Prius with critical problems layered on top of tolerable problems that have been going on for months.

https://lusciousgarage.com/blog/prius_taxi_repair/

The Prius is the new Crown Vic to cabbies and Uber drivers. Although many cab companies don't give a [censored] about maintenance and I've seen a few Ubers and Lyfts at Jiffy Lube at least getting an oil change which is better than nothing.

The much exalted Panther here has some of those problems - a Ford mod motor and a Toyota 1NZ/2ZR engine do have a nasty habit of drinking oil as they get older.

To their credit, they are actually fairly durable for the abuse they get in those use cases. I'm curious to see what's under my valve cover and the 2nd gen cars are known to drink oil when they older, I've cut down the consumption with MMO/BG 109 treatments and I plan on keeping my gen 2 for a while even if I get a new car. Prii are great city cars(I think better than a Fit). I think for laughs and giggles I want to re-ring my motor if I feel like it. Except for some Pennzoil Conventional and Quaker State Conventional, mine has seen PP and M1 mostly.

 

[gathermewool]

Originally Posted by RamFan
Nice pics. What was the reasoning for scaling back from 10k to 5k oci?


+1

However, you probably wouldn't have had that HG issue if you'd gone to 5k sooner!

 

[The Critic]

Originally Posted by gathermewool
Originally Posted by RamFan
Nice pics. What was the reasoning for scaling back from 10k to 5k oci?


+1

However, you probably wouldn't have had that HG issue if you'd gone to 5k sooner!

I noticed that the oil was getting quite dark towards the end of the 10k interval. This was not an "issue" when the engine was newer. Plus at about the same time, reports of oil consumption were starting to trickle in. So I decided that moving to a 5k drain would be my best insurance against developing oil consumption.

 

[bbhero]

^^^^^^^

Very smart move.

 

[Raidin]

Hi guys. I didn't want to hijack the thread, but wanted to chime in with my experience, since I had essentially the same thing happen to my 2014 Lexus CT 200h (which uses the 3rd gen Prius powertrain).

Like most Prius models, I also experience the same strange vibration and shuddering on cold starts on rare occasion (a misfire issue reported in a TSB, and still happens with the fix albeit less often). But, when my HG blew, my mechanic noticed it is common for it to happen on high-mileage Prii (there are no records on this for the rarer high-mileage CT 200h) due to what he sees as a possible defect in the engine, as it seems to happen with cylinder 2 each time. That was also my cylinder number that had the problem. It seems a misfiring cylinder #2, along with who knows what else, caused coolant leakage into the cylinder and throttle body.

I had him do the head job along with replacing a few things while we were at it since this was going to be a long-term car for me (I bought it just for work, where I drive 100k miles a year on the same route, mostly highway).

As a note, this happened at 375k miles, and my car is currently at 457k miles. OCIs were 5k miles until around 80k miles, where I started to explore oil reports and longer OCIs through Blackstone Labs. I was able to reach 28k mile OCIs with no issues on reports. Once the HG blew, I felt it may be best to go down a bit on the OCI, and switched to 15k mile OCIs because I have been using Mobil 1's 15k EP 0W-20 (before that I used the AFE type and whatever the dealer used before that).

I took some pictures for documentation (the burnt spark plug is from cylinder #2):

 

[UNC151]

Originally Posted by ekpolk
And, to get back squarely on topic, the OP's pictures just cemented my decision to switch from the AFE 0w-20 to the EP on my new car. I don't think that the AFE will do any harm, but this is essentially the same engine I have, and I like what I see here!
Unless you are going to run the EP much, much longer than the AFE you will see ZERO difference except your wallet being lighter. I ran Mobil 1 Advanced Fuel Economy 0w20 and 0W-20 EP in my 2010 FX4 for up to 18K miles and the AFE performed better (via used oil analysis results) than the EP did. YMMV.

 

[slacktide_bitog]

Wow that looks good

 

[nthach]

Not sure if this was mentioned: http://carspecmn.com/prius-engine-rattlemisfire-p0301-p0302-p0303-p0304-latest-news/

 

[SatinSilver]

Does the car consume any oil and anything else being replaced while this work is being done?

 

[ekpolk]

Originally Posted by 2015_PSD
Originally Posted by ekpolk
And, to get back squarely on topic, the OP's pictures just cemented my decision to switch from the AFE 0w-20 to the EP on my new car. I don't think that the AFE will do any harm, but this is essentially the same engine I have, and I like what I see here!
Unless you are going to run the EP much, much longer than the AFE you will see ZERO difference except your wallet being lighter. I ran Mobil 1 Advanced Fuel Economy 0w20 and 0W-20 EP in my 2010 FX4 for up to 18K miles and the AFE performed better (via used oil analysis results) than the EP did. YMMV.

I don't dispute your results for a minute, but I do plan to extend later on. Also, though I haven't studied the issue in detail yet, I don't have an answer for the mysterious consumption I experienced in the Gen-2 car on AFE that didn't happen with the EP. I am not, repeat NOT, claiming or implying that AFE isn't a fine oil (your results would seem to confirm that it is). When it's time, I'm going to pore over the reported used oil analysis, dig up what other info I can, and ask Terry Dyson for a final update (his input is part of my current thought).

 

[aquariuscsm]

Originally Posted by StevieC
Originally Posted by aquariuscsm
What I always wonder is what causes those scars around the circumference of the cam lobes? Would a thicker oil prevent that? Is it only ascetics? My 300ZX's cam lobes were perfectly flawless with no marks at all (it got 15W50/20W50 most of its 119,000 miles),but my Accord has those same marks on the cam lobes. Does thicker oil prevent that,or does my 300ZX have a tougher camshaft? Just something I've always wondered.

If you are talking about the dark ribbon type rings around the lobes that is burnishing effect and it's normal. It appears on vehicles running 20w50 as well.

A scar would be like the thin line on the cam lobe to the left of where the #34 is on the front cam. (Although this could be the lighting, but if it isn't that's what scaring would look like and it can be much worse than this)


What exactly causes that burnishing effect? I was looking at this thread and the camshaft lobes look perfect with no markings:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/5026477/1/garnish-on-valves-and-camshaft

 

[Raidin]

Originally Posted by nthach
Not sure if this was mentioned: http://carspecmn.com/prius-engine-rattlemisfire-p0301-p0302-p0303-p0304-latest-news/


Last time I checked, the TSB was in place for certain models of my car, the Lexus CT 200h. At or before 2014 (my model year), it doesn't call for an intake manifold replacement anymore (my guess is that these cars started coming with the revised manifolds) and instead called for a software update. I have this update on my car as of my HG's replacement, and I have gotten one or two of these cold start up shudders since. The update specifically states that it was designed to reduce these cold soak start up vibrations, not eliminate them.

 

[The Critic]

Originally Posted by Raidin
Hi guys. I didn't want to hijack the thread, but wanted to chime in with my experience, since I had essentially the same thing happen to my 2014 Lexus CT 200h (which uses the 3rd gen Prius powertrain).

Like most Prius models, I also experience the same strange vibration and shuddering on cold starts on rare occasion (a misfire issue reported in a TSB, and still happens with the fix albeit less often). But, when my HG blew, my mechanic noticed it is common for it to happen on high-mileage Prii (there are no records on this for the rarer high-mileage CT 200h) due to what he sees as a possible defect in the engine, as it seems to happen with cylinder 2 each time. That was also my cylinder number that had the problem. It seems a misfiring cylinder #2, along with who knows what else, caused coolant leakage into the cylinder and throttle body.

I had him do the head job along with replacing a few things while we were at it since this was going to be a long-term car for me (I bought it just for work, where I drive 100k miles a year on the same route, mostly highway).

As a note, this happened at 375k miles, and my car is currently at 457k miles. OCIs were 5k miles until around 80k miles, where I started to explore oil reports and longer OCIs through Blackstone Labs. I was able to reach 28k mile OCIs with no issues on reports. Once the HG blew, I felt it may be best to go down a bit on the OCI, and switched to 15k mile OCIs because I have been using Mobil 1's 15k EP 0W-20 (before that I used the AFE type and whatever the dealer used before that).

I took some pictures for documentation (the burnt spark plug is from cylinder #2):


Thank you for sharing your story. It does seem like these engines have a "defect" in their headgaskets where cyl #2 is often the point of failure. How long have you been doing extended drains? Your valve cover and valvetrain seem to be quite stained in comparison to mine.

Originally Posted by SatinSilver
Does the car consume any oil and anything else being replaced while this work is being done?

No oil consumption. It will be receiving all new gaskets (I ordered the engine overhaul gasket kit), thermostat and head bolts. The water pump was replaced 5k ago so it will be reused.

 

[caprice_2nv]

My coworker just had a Prius come in for him to check out a slight "rattle". It was a horrible rattle/misfire - head gasket had failed. Not sure on mileage. I don't think it was a taxi though.

The op engine sure looks nice and clean.

 

[CR94]

Head gasket failure is a common problem with these, as is excessive oil consumption.

Had the complete EGR system (cooler, valve, connecting pipe, and intake manifold EGR passages) ever been unclogged on this engine? Current conventional wisdom on PriusChat seems to be that the head gasket failures are caused (or at least accelerated) by insufficient or unevenly distributed EGR flow due to clogging. As far as I know, that theory hasn't been definitively proved or disproved. Had the engine made unusual knocking noises (besides the common cold-start shake) or misfired a lot prior to the head-gasket failure?

Mine has had zero engine (or other drive-train or electrical) issues thus far, except a single brief episode of cold-start shake.

 

[cpayne5]

Originally Posted by The Critic
Originally Posted by cpayne5
Originally Posted by BMWTurboDzl
Weird question: Do the red colored links on the timing chain signify something?


They are used to install the chain and properly time the engine using marks on the crank and cam sprockets.

In the pictures above, you can see that the mark on the right sprocket lines up between the two colored links. On the left cam, there should be a mark that lines up to the middle of the colored link. Same with the crank.

Timing this engine was not exactly a quick process. More info here:
https://www.toyoheadquarters.com/threads/toyota-2zr-fe-timing-chain-marks-1-8l.457/


What made it difficult? Not much slack in the chain to work with? Looks like all the appropriate marks are in place.

I've done a few Toyota chains, but never one on this engine.

 

[The Critic]

Originally Posted by CR94
Head gasket failure is a common problem with these, as is excessive oil consumption.

Had the complete EGR system (cooler, valve, connecting pipe, and intake manifold EGR passages) ever been unclogged on this engine? Current conventional wisdom on PriusChat seems to be that the head gasket failures are caused (or at least accelerated) by insufficient or unevenly distributed EGR flow due to clogging. As far as I know, that theory hasn't been definitively proved or disproved. Had the engine made unusual knocking noises (besides the common cold-start shake) or misfired a lot prior to the head-gasket failure?

Mine has had zero engine (or other drive-train or electrical) issues thus far, except a single brief episode of cold-start shake.


At around 160k, I cleaned the valve and pipe. At 179k, the intake, egr cooler, egr valve and egr pipe were cleaned. None of the items were clogged.

Until the headgasket failure, the engine has never exhibited a cold-start knock.

Originally Posted by cpayne5
Originally Posted by The Critic
Originally Posted by cpayne5
Originally Posted by BMWTurboDzl
Weird question: Do the red colored links on the timing chain signify something?


They are used to install the chain and properly time the engine using marks on the crank and cam sprockets.

In the pictures above, you can see that the mark on the right sprocket lines up between the two colored links. On the left cam, there should be a mark that lines up to the middle of the colored link. Same with the crank.

Timing this engine was not exactly a quick process. More info here:
https://www.toyoheadquarters.com/threads/toyota-2zr-fe-timing-chain-marks-1-8l.457/


What made it difficult? Not much slack in the chain to work with? Looks like all the appropriate marks are in place.

I've done a few Toyota chains, but never one on this engine.

I should have set TDC manually. When you follow the directions by toyota, they ask you to rotate the engine until the colored links match up with the marks on the cam gear and/or the phasers. This can take many many revolutions.

 

[caprice_2nv]

Around here all the Camry Hybrid cabs sound like they are rattling their brains out with detonation when they drive by. I haven't noticed it on Prius cabs though. Probably 60% of our cities cabs are Camry's, the rest are either Prius, vans or impalas and then some misc.

 

[ZeeOSix]

Super clean ... looks brand new.

 

[Raidin]

Originally Posted by The Critic
Originally Posted by Raidin
Hi guys. I didn't want to hijack the thread, but wanted to chime in with my experience, since I had essentially the same thing happen to my 2014 Lexus CT 200h (which uses the 3rd gen Prius powertrain).

Like most Prius models, I also experience the same strange vibration and shuddering on cold starts on rare occasion (a misfire issue reported in a TSB, and still happens with the fix albeit less often). But, when my HG blew, my mechanic noticed it is common for it to happen on high-mileage Prii (there are no records on this for the rarer high-mileage CT 200h) due to what he sees as a possible defect in the engine, as it seems to happen with cylinder 2 each time. That was also my cylinder number that had the problem. It seems a misfiring cylinder #2, along with who knows what else, caused coolant leakage into the cylinder and throttle body.

I had him do the head job along with replacing a few things while we were at it since this was going to be a long-term car for me (I bought it just for work, where I drive 100k miles a year on the same route, mostly highway).

As a note, this happened at 375k miles, and my car is currently at 457k miles. OCIs were 5k miles until around 80k miles, where I started to explore oil reports and longer OCIs through Blackstone Labs. I was able to reach 28k mile OCIs with no issues on reports. Once the HG blew, I felt it may be best to go down a bit on the OCI, and switched to 15k mile OCIs because I have been using Mobil 1's 15k EP 0W-20 (before that I used the AFE type and whatever the dealer used before that).

I took some pictures for documentation (the burnt spark plug is from cylinder #2):


Thank you for sharing your story. It does seem like these engines have a "defect" in their headgaskets where cyl #2 is often the point of failure. How long have you been doing extended drains? Your valve cover and valvetrain seem to be quite stained in comparison to mine.


I started going above 5k OCIs at around 80k miles. I switched to 15k OCIs at 375k when the HG failed. There was a tiny bit of gunk that looked like sludge to my mechanic, which he always worried might happen with extended OCIs. This is another reason I decided to roll them back.

I assume the staining overall is due to running coolant with the oil. That's the chocolate milk looking gunk you can see in the photos. My engine otherwise looks more like yours under normal circumstances.