P0016 Code 2004 with 443,000 miles

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Highmile, Dec 27, 2019.

  1. Highmile

    Highmile New Member

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    Hello Everyone,

    This is my first time posting to the site. I have a 2004 Gen 2 prius with 443,000 miles. I do all the maintenance myself since I bought it with 50,000 miles.

    Original battery and engine and most of the suspension. The car is a tank. I recently have been getting a P0016 code and was looking for suggestions. I understand this may be a timing chain issue.

    I would like to keep this car going........

    Anyone that can comment please. Thank You!
     
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  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Quite the impressive run you've had there.

    Our advanced search feature is working once again, try doing a few searches and see what you find in relation to that DTC.

    With 443,000 miles, have you already checked/replaced the timing chain and tensioner?

    You might try inspecting/cleaning the vvti oil control valve and filter: VVT Oil Filter? Poor MPG'S? | PriusChat

    Not sure if this link is useful : Toyota Prius P0016: Crank/Cam Position Correlation – Bank 1 Sensor "A" | Drivetrain Resource

    Below are some other options:

    P0016
    Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
    - Valve timing
    - Camshaft timing oil control valve assembly
    - Oil control valve filter
    - Camshaft timing gear assembly (for intake camshaft)
    - ECM

    Please report back in this thread once you find a solution, or if you're still having issues.
     
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  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Yes. Basically you would turn the crankshaft pulley to get cylinder 1 to top dead center (TDC), then remove the engine valve cover and see whether the centers of the colored links on the camshaft timing chain line up with the marks on the camshaft pulleys. (It might be necessary to rotate the crankshaft another 360 degrees if the camshaft pulley marks don't appear where expected.)

    If you find the timing is off a little then that shows the chain has stretched or slipped a tooth.
     
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  4. Highmile

    Highmile New Member

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    Ok thanks all.

    I will start by taking the valve cover off and checking the marks. Seems like the best place to start. Timing chain is inexpensive, around $60. My time will be extensive to complete this repair.

    Will also check the vvt filter. That seems fairly easy.

    The engine runs well, however recently I have seen a drop in fuel economy 38mpg from my typical 43 mpg and a slight rumble at idle. Not every stroke but it does appear rhythmic.

    Code p0016 reappears within 2 trips after clearing, so likely a real problem.
     
  5. Highmile

    Highmile New Member

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    Update...I have taken the vvt solenoid and filter out. They were extremely clean. I have a new timing chain coming Saturday. I plan to pull the valve cover this weekend and check the timing belt position. If its on time, I may suspect an issue with the VVT gear. Symptoms currently are at idle, getting a small intermittent rumble from the engine. Fuel economy is about 41 mpg, down from 43 typical. Also when decelerating the engine idles high and it is slow to come back down. The P0016 is persistent and comes back after 2 trips. The car burns oil at about 1 quart every 1500 to 2000 miles. Mobile 1 5W30 since 50,000 miles. I change the oil every 10,000 miles.

    I will report back after the weekend.
     
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  6. Highmile

    Highmile New Member

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    OK timing chain is on time visually. Motor is unbelievably clean. I guess the Mobile 1 really has done well for me. I can see both marks and the yellow links are centered properly on both upper sprockets. I have begun removing the engine mount and plan to tackle the timing chain tomorrow. I have had to remove more items than I originally thought.

    Any wise words of wisdom in terms of making sure I install the new chain so the engine is in time?

    Thanks
     
  7. SFO

    SFO Senior Member

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    Hopefully someone who has done this before will chime in. But I was thinking the below might be a good idea.

    Starting at about 12:00 in this video, you can 'fix' the cam with a folded paper towel under the cam cap.

     
  8. Dxta

    Dxta Senior Member

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    Y not post pictures of the visuals of the timing chain inspections? If I get this correctly, the gen3 has a 1.8L 2ZR engine, same engines on some corolla 2009-current.

    I have fixed lots of these engines, and discovered some of the suggestions I'm penning down to you.

    On those engines, the timing marks on the camshafts may have misaligned from their marks, or the intake/exhaust camshaft gears(the VVTi gears), may also be problematic.

    The funny thing with the 2ZR engines is that they don't have alignment marks on the camshaft bearing caps, in which to line them up with the can gears.

    You got to be very careful, when trying to line up the can gears. Easy way is to have the #1 cylinder coming up to TDC, and aligning the crank pulley mark to zero on the timing chain cover.

    Did you carry out the procedures above, or you just did opened up the valve covers, only to look at the camshafts?

    If you did carried out the timing chain alignment checks properly, my next guess would be for you to inspect all the timing chain guides. At that mileage, some bits would have broken off and fallen into the engine, causing the codes you're getting.

    The timing chain auto tensioner should also be inspected and replaced.

    I see this as a job, you may not want to embarked upon.

    Keep us posted though.
     
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  9. Highmile

    Highmile New Member

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    Hello All,

    Thanks for the info. This is a 2004, so it has the 1.5l engine which is a bit different that the 2010+ prius 1.8l.

    I have just replaced the chain and tensioner as well as the guides. I am close to putting the cover back on. Nothing broken, but visually could see the difference in chain length from old to new. Also now there is no slack in the chain. Marks are dead on after a few full rotations. Looks much better.

    Now I need to get it all sealed. I will post pics after I am complete.

    Will keep you posted.
     
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  10. Highmile

    Highmile New Member

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    OK so I think I solved the issue. Timing chain was replaced along with the tensioner and 2 guides. P0016 Code is gone and I have been about 200 miles and at least 5 trips. Mileage is back to 43 mpg with 65-75 mph driving. Unfortunately my photos did not come out great as the lighting was terrible.

    The old chain was noticeably longer than the new chain. I would estimate about a half of a link longer.

    The engine was remarkably clean for over 440K miles.

    I have some thoughts about the job. It is not for the faint hearted. I was deeper into the motor than I wanted to be with many unknowns. With that said it was definitely worth the experience and is a 8/10 for difficulty. I recommend the appropriate factory service manual sections especially for the correct torque specs for the many fasteners you will be removing and reinstalling.

    The motor mount must be removed to access the timing cover. This means jacking the motor and removing or relocating the brake reservoir and washer fluid reservoir. Crankshaft pulley can be a challenge to remove as the torque spec is very high.

    I replaced the water pump, spark plugs and the passenger side lower control arm and lower ball joint during this job. The lower control arm was in need of replacing and the motor mount must be removed to get the forward most bolt past the oil pan. The engine must be raised up about 2 inches to accomplish this only for the passenger side. The ball joint bolt was stripped and took a few hours to get out and included the use of a sawzall and dremel to remove.

    Timing chain installation was not difficult but I did run the motor through a couple of cycles by turning the crank shaft to make sure the timing marks aligned. Prior to removal of the old chain, try to get the marks aligned and this will make the new install much easier.

    Timing cover requires very careful cleaning especially the mating surfaces on both the cover and motor prior to installation. I used a high quality oil resistant gasket maker to reseal. New gasket on the crankshaft must be used. There are 2 internal o rings replacements that are recommended but mine were in great shape so I left them.

    Space is tight but was adequate. Reinstallation of the timing cover required careful alignment of the oil pump and crankshaft. Also I installed the cover from the bottom and was careful not to smudge the gasket material and I torqued all of the cover bolts within 20 min of install. This was challenging. Have your sockets lined up prior to starting.

    FOLLOW THE TORQUE SPECS!!!! There is allot of aluminum here all on the engine . Leave the hulk like tightening for another job.

    I was nervous to start it but all seems well now. It took about 5 days total of about 12-15 hours including 5 for the control arm and about 2 of me second guessing the timing of the old and new chain.

    Oil is cleaner than ever and both the coolant and oil seem to be staying away from each other. This was a big concern of mine with regards to sealing the timing cover properly. They can mix if you are not careful.

    Motor is running smooth and all is well.

    I am sorry for the long post and I know it is a bit disorganized. If you have a P0016 are considering this job I would say do it if you are comfortable with the items I mentioned above. If anyone has questions, ask and I will do my best to respond.

    Thank you all for the comments that lead me to this fix!!!!
     
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