What’s inside a 500,000 km Toyota Engine?

Ever wonder what’s inside an engine with over 300,000 km?

In this video we teardown a Toyota Prius 1NZ-FXE 4 cylinder engine from a 2004 Toyota Prius. The engine features drive by wire throttle body, cast aluminum intake manifold, aluminum head and block, dual over head cams with variable valve timing on the intake, an accessory belt for the water pump only, and a timing chain powering the two camshafts.

The Prius engine is the detuned version of the 1NZ that makes less power but is more efficient because it runs on the Atkinson cycle.

After removing the oil pan, timing cover and valve cover it is evident that after 17 years and 300,000+ miles the engine is tarnished dark on the inside. The oil control rings are clogged, and carbon buildup is evident on the piston heads. The bottom of the sludge and oil pickup is lined with sludge. The intake system has carbon buildup from the PCV system. In conclusion, while there is no evidence of mechanical wear just due to high mileage, the lesson learned here would be to take care of the oil system in your engine if you want it to last longer than the rest of the car.

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41 thoughts on “What’s inside a 500,000 km Toyota Engine?”

  1. Even with 10+ years of experience in mechanical design engineering.. it's very difficult to understand this technology .

  2. It was said at the very end, this engine is not used all the time since it is a hybrid, what's more impressing is engines that run all the time. My 2005 Mazda 3 has 690 000 and is still running no issues! Just battling rust!!!!!

  3. Good video,we don't know what oil filters brand was used during the 300,000 kms,right? From the looks of the BEARINGS and cam caps and bores, i would have to say whatever BRAND was used THEY WORKED GREAT> Let's say 5,000 kms per oil change =60 oil and filter change? and bearing were like new!!!!! TRUTH is we don't really know,BUT THE BEARINGS TELL US the story.ON the oil control rings my 1994 Honda civic went 500.000 thousand miles BEFORE i had to REPLACE ONLY the Standard rings.Because the oil control flow back HOLES completely closed up. I drilled them clean,the rod and mains looked new like those so i left them in. honed the cylinders put in the new std rings and now 3 years later have 540,000 no oil usage,Hondas and Toyotas are ENGINEERED to last with maintenance.

  4. Looking at this video and reading these comments makes me question if i'm a real man. Gosh, everyone here is so knowledgeable and educated when it comes to engines. So much so that I think I started growing facial hair just reading them. Amazing.

  5. The more engine disassembles I see, the more I appreciate my four cylinder Mazda engine for it's simplicity and serviceability.

  6. Why is it that everyone on YouTube tries to use slip joint pliers, crescent wrenches, and vise grips in the wrong direction? 😉

  7. Is there any point in cleaning the throttle body and the manifold for this car and what would be the difference when cleaned?

  8. I couldn’t remember the name of your channel so I googled “brother’s teeshirt teardown” and found it. Thank god. Haha.

  9. I have a 2009 Toyota Prius. Not the most exciting drive, but… it's crash test rating is good, insanely reliable, comfy, practical, economical, roomy, ok standard equipment, cheap maintenance, a few dents and scratches here and there but I couldn't care less. Pretty much no oil consumption as well. Despite its image, it's more than fast enough for everyday traffic.

  10. So I've never owned a hybrid or EV, but in the case of the hybrid does the control system log combustion engine running hours?
    Maybe even a ratio of total miles driven vs combustion engine hrs., of course ymmv your ratio may vary.
    That way, buyer of a combustion engine has an idea of its stats vs just the total miles driven.

  11. My 2012 Camry had a long block replacement at 57k miles. It had a lot of carbon on the pistons too. Covered under warranty due to knocking. The sound got worse when they applied volts to the engine.

  12. If this is how Toyota engine looks with cheap oil and filters after 500.000km I wonder what is the result with genuine Toyota oil and filters.


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