2012 Prius - CEL P0301 Cylinder 1 misfire/Engine knocking - FIXED

A fool's paradise. Not long down the road you could go from leaking head gasket to bent piston arm.

 

Sadly no licensed mechanic shop by me will touch a Prius or any other type of hybrid, except for stupid easy stuff tires brakes etc which is why I learned to do my own work.

 

I love this forum for the insight and knowledge. But, I suspect not everyone has the facility, means, and desire to keep their Prius in tip top shape. Some of us are just looking to keep it running a couple more thousand miles.
In my gen 2 I had to turn the heat on high for 10 minutes to overcome the MCD main display not working. I had to put a new plug in cyl 1 every 10k miles, and eventually started just going with the cheapest noniridium plug. I eventually used 5-30 oil in the 2nd gen. I’m actually thinking of trying 5-30 in my 2012. Hoping a more viscous oil can help with the deformation of my head gasket? Also, I’m thinking of trying to ad some AT-205 leak stop to the oil... again to mitigate the deformed head gasket.
I use “deformed” because I’m not convinced it’s “bad” yet. I caught the misfire early and immediately rebuilt the IM and EGR.... trying to stay optimistic.

 

So... I came to the Prius from Honda’s line of hybrids. I had two insights and a civic hybrid, all three were manual trans 5 speed. The first insight I put 40k miles on it in a year and was hit head on and it was totaled. It had a brand new big battery and honestly got 70mpg on my 160 mile round trip commute. The civic hybrid got 52mpg on that same commute. A week after its’ big battery was replaced, it was hit and totaled. Next I got a super cheap high mile insight with a bad big battery. I was able to register it just before Cali started requiring hybrids to smog. It got 55mpg just as a gas engine, with no hybrid system. That’s what I love about the Honda manual trans hybrids; they run as a normal internal combustion car if the hybrid battery craps out.

my point is.... where are all the mods for the Prius? There’s a Honda mod, where u splice a switch into a sensor that tells the car u have the clutch depressed, which essentially turns the IMA hybrid system off. It’s non evasive and causes zero Ecu or MIL issues. I watched the gasket masters video RE the 2ZR engine... it’s the same engine in the matrix, corolla, tc, Xb and it doesn’t have the head gasket warping issue.
Where’s the Prius mod to keep the ICe on always? Turn off the auto stop? Bypass the hybrid system?

yes, we bought a Prius for the high mpg, but we also need first and foremost transportation!

 

I agree with you Mendel. User should just get a leak down test and if gasket is blown, put plan b together for replacement vehicle. No use of throwing parts (money) at it if gasket is blown.

 

I'm not sure that starting the engine is what works the damper springs the most (whether in a hybrid or conventional car); there's a lot more going on with those than a person might guess, and they break sometimes in conventional cars too. There probably is existing research on what really are the biggest contributing factors, that a good librarian could help find. I'm not familiar with it myself; if I got tasked with finding out something about it, I'd have to start there, not by trying to reason it out from my own assumptions.

 

That is kind of sad! I would personally think a compression and leakdown test would be "stupid easy"... Well then my next best recommendation would be to do it yourself: It really is "stupid easy", all you have to do is buy the tool, attach it, and crank the motor... Test all FOUR cylinders - log results... Compression test comes first, then a leakdown...

Here are some videos for reference/help:

 

I understand, but, unlike other "traditional" cars (that use either a torque converter or clutch), a Prius is also constantly starting and stopping the engine... I am personally thinking this has got to be much worse on a component of this type in it's "position"...

Imagine if you will, you're driving a "traditional" manual transmission vehicle... Every chance you get, whenever you're capable of "coasting", you turn the engine off. As soon as you need the engine again, of course rather than use the electric starter (since you're already rolling/moving), you "pop the clutch" in order to get the engine re-started again! And you did this HUNDREDS of times PER DAY!!!

I envision that as being MUCH more "stressful" (on ANY such "damper" components) than the "typical" vibrations they're inherently designed to "dampen"...

 

Remove O ring from coolant cap is never meant to be a fix so you can keep on driving.... It help not hydrolock your motor if you have to move your vehicle.. still have to get it fixed if you do have a leaky head gasket..

Posted via the PriusChat mobile app.

 

I understand what you're 'envisioning', and I'm not saying I know it's wrong, but your envisioning seems to be missing both a literature review and a controlled experiment, and any engineering conclusion would generally be held off for at least one or the other.

 

I dropped her off at Hybrid PitStop in Buena Park this morning. $1400 for the head gasket, and he sold me on an oil catch can for $195. I’ll update.

 

On a normal car, exactly. But as far as I know (and what the service manual says), that "crank the motor" part is not so easy on these engines - at least to do it in a controlled way such as cranking for 10 seconds as you might do on a regular car.

Service manual specifies for the compression test to be done via Techstream. Basically you screw in the regular compression gauge, depress the gas and brake pedals, and let Techstream do its thing. I don't know if it manages valve lift / timing as well as engine RPM while doing the test.

I can fully understand why an indy professional who may have great ability and confidence in working on non-hybrid cars would decline to work on them, unless they are short on business with the non-hybrids.

BTW, similar fundamental differences / difficulties when dealing with the brake system. And of course the transmission is from another planet.

 

I can fully understand why an indy professional who may have great ability and confidence in working on non-hybrid cars would decline to work on them, unless they are short on business with the non-hybrids.

they’re afraid of getting electrocuted :-(. I got a mechanic in my locale to replace the clutch master cylinder on my 2000 Honda Insight, but only after I flipped the 50a breaker to turn the hybrid system off. I usually do all the work myself, but I am glacially slow, and I was in a hurry. I reckon I could pull the orange safety thingy on the Prius;-)

 

Haven’t meet anyone who doesn’t mind getting electrocuted

 

So... one month after getting my leaky head gasket fixed at Hybrid Pit Stop, I’m feeling pretty good about it. I’ve only driven about 600 miles since the repair, but the car feels great, and the transition from electric to gas is not even noticeable. Again, this is a 2012 plug in with 248k miles that “had the shakes” and was showing CEL p0301.
I had installed new spark plugs, moved the coils, and cleaned the egr cooler, all to no avail... the shakes persisted. So, I faced the sad fact that it was the head gasket:-(.

I heard nothing but good stuff about Hybrid Pit Stop from this forum and emailed them. It took a couple days, but they called me back and quoted me $1400 for a new head gasket over the phone. So I set up an appointment for 9am on a Wednesday. I live about 75 miles from their shop. I’m in Crestline CA and they’re in Buena Park CA, Beach Blvd exit off the 91 freeway, very close to Disneyland, Knotts Berry Farm, and the Pacific Ocean. Each time I had to drop off or pick up the car I went for a swim, which was great as SoCal was in the grip of a serious heat wave.

Once they got serious under the hood, I did get a couple phone calls suggesting a couple things.... sadly I am broke, having not worked in months due to this crazy covid thing. I ended up getting a new water pump, pcv valve, air intake manifold cleaning, new head gasket, oil change, and all new fluids and other gaskets for $1793 out the door. Cash money, the folding paper type. I’d agreed to an OCC for $200, but had them nix that because it seems fairly straightforward to do myself. Roger from HybridPit even showed me exactly how to do it myself; which hose to splice and where to rest the actual oil catch can.

Overall, Hybrid Pit Stop gets a FIVE STAR review. There was one hiccup... they called me on Friday around noon and said the car would be ready at 5pm. So, we headed down for a swim before picking it up. At 4pm I got a call saying that sadly they had crimped a fuel injector o ring on the re-install and weren’t going to be able to get me the car until the next day, as it was too late to get another OEM o ring. That’s gotta be a tough call for them to make.. knowing I drove so far and would have to do the same drive again the next day. They knew I’d be pissed off, and I truly was. But, I quickly realized that this was a sign of the shop’s integrity and honesty.

So yeah, I really liked my experience with Hybrid Pit Stop in Buena Park, CA and would highly recommend them. They seem to mainly be a performance, mod, and tuning shop, and suggested sway bars, suspension upgrades, etc, but as soon as I told them I’m a hyper miler just looking to drive like a grandma til the wheels fall off they backed off. Again, a truly five star experience!

 

Ok husband replaced the EGR valve, plugs and coil packs. Noise stopped briefly then returned. Coolant was low so he feared head gasket. Took it to Toyota dealer and they charged me $72 to tell me to find out for sure it would be. $300 service fee but most likely the head and it would be $4300 to fix! So I said I would pick it up. Anyone have any suggestions of a good mechanic in North Alabama around Decatur or Huntsville?

 

I don't know your area, but your issue puts you in the range of either replacing the head or putting in a newer/low mileage engine. Which ever process takes less time for the mechanic, will mean less of a labor charge.

 

If nothing’s warped installing the Toyota gasket kit (includes head gasket) may do the trick. New head bolts, while not mandatory (as long as head bolts are still within specs) is the prudent way to go. The outlay for parts is then quite reasonable, but labour will still be significant.

 

2013 model. Rough start/knocking on warm starts, got worse over 2 days. Cylinder 1 misfires code. Bought a plug and coil, but started reading this thread and it sounded more like a head gasket issue. I took the cap off the coolant reservoir and the symptoms went away. Dropped it at the dealer, they came back with a EGR/intake valve/spark plug replacement diagnosis. I felt they hadn't properly considered the symptoms and hadn't checked the head gasket. So they performed another diagnostic the next morning and assured me the head gasket wasn't leaking. So, I let them charge me $2110 for their cure. After driving for a day, the symptoms returned. I alternated driving with and without the reservoir cap on twice and the CEL returned with the cap on, and the symptoms were negligible or gone entirely with the cap off.

I don't think they replaced the coil packs, not sure why? I'm taking it back to the dealership this afternoon. Any ideas what might cause this behavior if it's not the EGR system or head gasket, that also explains the symptom relief by taking the cap off?

 

Likely is the head gasket, more'n likely due to neglected EGR circuit. What they've done is the rolls royce cure, but way too late. Periodic cleanings of the EGR, say 100k miles at most for first, and 50k miles thereafter.

They replaced the intake manifold, and all EGR components?

What's the miles on it?

To check head gasket: leak-down test and/or boroscope inspection of the cylinders while the coolant system is pressurized.