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Are JDM Engines Reliable or Risky?

Are JDM Engines Reliable or Risky?

Japanese Domestic Market engines, reliable and popular in the Asian market overseas. Built and designed for many models exclusive to the Japanese market, are they a risky investment after their time overseas? Realizing the potential profit companies stateside have started to sell “JDM engines”. Many car enthusiasts are now asking are they reliable enough to purchase and what risks could that entail?

Are JDM Engines Reliable or Risky? JDM Engines are extremely reliable, however not every engine will be treated equally. Multiple factors such as authenticity (not a fake), mileage, maintenance, and other factors with a certain JDM engine holds its reliability or is a risk.

Generally speaking, people who do purchase authentic JDM engines have positive outcomes, never expect a guarantee on if a JDM engine is reliable. Continue reading on for other factors to consider, as to avoid buying a lemon of an engine.[1] 

Are JDM Engines Reliable or Risky? The Real Facts

A quick read through this article from explains the difference quite well. A true JDM engine as quoted from the article is a “product specifically produced for the Japanese market and can be classified as a true JDM”. Any parts that were manufactured for the states are otherwise spec’d closely to their Japanese counterparts but not true JDM engines.[2] [3] [4] [5] 

A good read and a lot of description from as to why JDM engines have so low mileage and remain reliable are due to Japan’s culture and strict inspection rules. In Japan, it is considered a status symbol to have a new car. As reported in the article the average age of a vehicle is 7 years.

Part of this is also due to an inspection that is called Shaken. This is inspection is incredibly thorough. Were talking so detailed that a scratch or even rust will fail the car. Ways a car could fail the Shaken inspection include:

  • Dents
  • Undercarriage Damage
  • Emissions test allowing only 1% variation
  • Headlights must be perfectly aligned
  • All other lights in working condition
  • Interior inspection

The Shaken inspection is one of the biggest reasons JDM engines become available at such low milage and seem as reliable as they are. They are barely driven but it’s how they have been driven that could increase the risks involved.

Typically after their third inspection, the vehicle will fail. Allowing the engine and even the transmission to be made available for sale. Also, the inspection fees are pretty high, and they only go up as the car ages.

Another downside is that even though the cars are inspected a driver could swap out certain components before and after the inspection even takes place. Fudging the results and increasing the risks that even if the engine still seems okay it could affect the overall life span of the JDM engine.

Rigorous inspections would indicate these are good engines to go with. By the time they are used in Japan, they are still considered good engines stateside based on miles. Also, the cost is a good price point in most cases coming in at around $4,000 depending on the model. A true JDM engine could be a very reliable choice if one was looking to get a good dependable engine, thanks to Japan’s strict rules.

Aftermarket Japan Market

As with anything aftermarket, there is always a risk. However at the cost sometimes the risk is worth the reward. The riskier part, however, is that many sellers for car parts claim to be JDM which may or may not be true. I did some google searching myself to see what I could find.

The way I went about it was to look into the website a bit further. Going to the companies about pages to see what is claimed. My goal was to determine if the parts truly came from Japan and if the company seemed to be legitimate. Here are the few I found.

  • The first one I found is Japan Parts Service. They specialize in importing used parts directly from Japan. They seem to have a simple yet effective About Us page and their FAQ page seems ok as well. They answer important questions such as what mileage is on the engines they buy, as well as how often it can be expected to receive orders from Japan.
  • The second is Dallas JDM Motors located in Arlington, TX. They have a nice clean website but finding information on their practices seems difficult. They claim that their engines are directly imported from Japan and they do have warranty information but that is about all there is available on their site. As far as first impressions go these guys would need some more research done in order to be trusted.
  • Lastly, I found Funky Power. Their website is just as crisp as the others, but the difference here is their well thought out About Us page as linked before. They include a lot of information about themselves including they’ve been in the business since 2002. This website is one I could definitely get on board with the downside is they are European based. I included this example though because these would be the type of sites one would want to find, as the details really reinforce the trust to buy from that company and get genuine JDM parts.

Some other things to look out for are JDM myths. A great resource is at Superstreet Online. A couple of myths include

  • After a certain amount of miles a car can no longer be on the road also confused with the strict rules with Shaken
  • The car wasn’t driven hard. As reported from Superstreet Online, these cars are bought to drive and to drive fast. Cars using JDM engines are not your grandma’s ride

The article goes on to explain other important things to look for when buying an engine for a swap. Going into detail on what to look for and all sorts of stuff which is worth a read also.

Final Thoughts

With any major purchasing decision, a lot of thought and research should go into it. Wanting to do an engine swap to create a new, sweet ride that has plenty of horses beneath the hood is a dream to many car enthusiasts.

It is crucial that not only with JDM engines that you know what you want and what to look for. Very few experienced buyers strike a deal with any business without knowing exactly what they want and how it should be.  Keep in mind the following details to look for, and it will increase your chances of getting a reliable engine that can be used for years to come;

  • Warranty, a good warranty can go along way to eliminate any risks
  • Mileage on the engine, this can tell you many things but also how close it is to needing other major components replaced
  • Is the engine from a wreck? Knowing this can tell you if there could be damage hidden from the naked eye
  • As much history about the engine as possible. This may not be easy to find but the more you know the better
  • Age, this will also indicate how much life it could have left
  • Manufacturer, some are better then others, just as the Ford, Chevy, and Dodge are debated endlessly state side some makers are not equal to others, same goes for specific car models as well
  • Horsepower and Torque, good numbers from these could help indicate a good buy
  • Compatibility with whatever you plan to put it in. Before buying again make sure you know what you need and want not just the latter
  • Things you have to do upfront. Some places may require certain fluids, and/or gaskets, seals and other things to be replaced prior to your warranty being activated
  • Shipping times, and who’s involved. Knowing these things you can check the reputation of said companies protecting your investment further


JDM engines are some of the post powerful, sleekest engines that are built. With their short lifespans and low mileage from our counterparts in Japan they could be just the thing you need to tweak that awesome ride. Making it go from meh to damn in a matter of months. As awesome as that would be protecting yourself is just as important.

Keep in mind the above points and you should be well on your way to getting a decent engine. One that can provide years of reliable, dependable service. Just remember if some didn’t take risks we may not even be talking about these engines today. Good luck and happy swapping!

Learn More

If you want to learn more about JDM Engines, then check out this book on JDM Engine Secrets on Amazon.