2012 Prius V engine with timing chain cover off.

This is what the engine should look like before the timing chain is off.

[@metrork1]

Wow, your missing one of those small "O" rings.

[@ecojim1]

Just to confirm, this is the correct orientation of colored links and marks. Adam's video of last January is showing the wrong orientation potentially allowing valves to hit piston (double link aligned with right mark on right cam). Adam, thank you for all your documentation of this process. I successfully replaced the head gasket on my 2010 Prius, thanks in no small part to your videos.

[@burg2daworld]

Jim does the chain marks matter when taking of the chain. Or does it matter most when putting it back? I've rotated this thing a number of times and still can't get the 2orange marks to line up on the intake side neither the single orange on the exhaust

[@ecojim1]

@@burg2daworld - I assume you mean "taking off the chain." I was lucky in that when I took off the timing chain cover the marks and links were very close to this alignment. Regardless, when reinstalling the chain all three points have to be in line to assure the correct relative orientation of the crank-, intake cam- and exhaust camshafts. That includes the single colored chain link on the dot on the crankshaft gear, the single colored link on the little rectangle on the exhaust camshaft and in between the two colored links on the left (when viewed from above) line on the intake cam (toward the front of the car or right side if the engine is removed and on a stand). I was having a hard time figuring this out. It helped when I realized that it takes several revolutions (probably 4 because of it being a 4 stroke engine) of the crankshaft to return all three to the correct orientation. (Obviously, rotating the crankshaft is only easy when the spark plugs are removed and it's a little difficult to keep enough tension on the chain during the process without the tension piston installed) This might be a little goofy, but to logically think this through, I took a short piece of a metal clothes hanger and cut it to about a foot long straight section and inserted it carefully through the spark plug hole to gently rest on the top of the piston (#1, closest to timing chain). As I rotated the crankshaft, this allowed me to see the relative position of the piston. That helped me confirm that the orientation of the three marks was correct. (cam lobe pushes intake valves open/down as piston goes down, both are closed as gas is compressed as the piston goes up, both remain closed as piston goes back down for ignition stage, then exhaust valve opens as piston goes back up pushing out the exhaust gas, then repeat). Standard disclaimer that I am not a professional and can not be held responsible for any damage caused to your car by this admittedly amateur approach. It worked for me. My prius seems to run fine now, though it "feels" like it idles at a slightly higher RPM for some reason. No codes or warning lights are visible. I am about to take it for emissions testing. I've had to drive it for a while to go through a "Drive Cycle." It would not complete the emissions protocol until then.

[@elijahcherkez9379]

@@ecojim1 higher idling still? Did you clean the EGR valve and small holes inside the 4 large holes of intake manifold to clear the carbon buildup?

[@ecojim1]

@@elijahcherkez9379 woah. That was months ago. Yes, as I recall. I was finally able to understand the correct orientation. Project was completed successfully with a 2-3 mpg average fuel economy improvement.

[@elijahcherkez9379]

@@ecojim1 what is the right orientation of the chain? I'm replacing the head gasket on 2011 Prius. So far I turned the crank wheel and see only one lighter chain as the color weared out. Does the chain have two individually colored links and one pair of two links that are colored?

[@goodshape6899]

nice video ...can you take full video explanation for sentering or how to correct register chain from bottom to top... try to find that party... it helps if explant or make video of that

[@AdamDeVries]

I'll try to make and post one in the next couple of days

[@lamutaafua]

Couple of basic questions...where u getting a specific DTC code? (P0012?) What were the symptoms of the vehicle that warranted u to disassemble and reset timing chain? To correct this, just disassemble as u did, align all the markings on the chain then put everything back together? Is there anything else needed to be done?? Do u know the torque specs on each bolts? I'm going to be doing this to my Prius and advice would be greatly appreciated?? Thank u

[@AdamDeVries]

the problem that I had was I had multiple marks that look like timing marks I should have marked everything before I took the chain off. the head gasket was leaking into one of the cylinders it would shutter really bad it was pretty obvious. When I took it apart one of the cylinders had been steam cleaned all the antifreeze leaking into it. I have other videos in the channel that go over the timing on the car

[@lamutaafua]

I can not find that video

[@dontcareboutname1]

@adam devries Just want too double check this is the correct orientation for the timing? It’s all accurately set up in the video now?

[@AB-yu2tj]

Thank you for the video. What if I need to check the timing chain tensioner could you tell me how I can check that without having to take the engine out. And is it possible to replace or tighten the tensioner without having to go and take engine out please please please thank you thank you

[@unkertech]

Yes, you can do it without taking out the engine cover. You just need to insert the tensioner with it all pressed in and held on by the clip. Then tighten it and turn the crank clockwise. You should be able to hear a click from the tensioner which indicate it has release from the clip and doing it tensioning work.

[@AB-yu2tj]

@@unkertech thank you for your reply

[@Elaba_]

0:40 What's the purpose of these 3 oil rings? What happens when they don't seal completely anymore?

[@AdamDeVries]

They are oil passages. It they don't seal you could have low oil pressure

[@abdoulayetraore8776]

Cv je peux vous demander

[@alloncedebreus6694]

Korolla