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5 Warnings About How You Could Be Killing Your Toyota Prius

If you love your Toyota Prius you need to read this article. Many Prius owners need to heed these warnings that they may be killing their car.

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I am here to help people understand how crucial it is to take care of any car if you want it to last a long time. I speak to many of the Prius owners. Many are not aware of how important these items are to the health and life of the car.

I put together five warnings to help Toyota Prius owners pay more attention to their cars and keep them on the road longer.

First Warning, Check Your Engine Oil Level
The Toyota Prius, as impressive as it is, does have an issue when pushed beyond limits. The Toyota Prius is an economy car, and sometimes this can get owners into thinking that everything about a Prius should be inexpensive. That is not always the case.

check the oil in the car

While a Prius is undoubtedly a robust vehicle, no doubt, using inferior products such as engine oil can cause other problems. Prius owners who are repeatedly using low-grade oil that breaks down quickly is a huge problem. The deposits that get left behind find their way into the piston ring lands and other places in the engine. Prius then to start consuming engine oil. Once this occurs, if the owner is unaware, the engine can run out of oil and cause complete engine failure.

The good news? BG products have a solution if you are one of those owners that may not be super aware of what your Prius is doing. Check out that article here. Whatever is happening, make sure you are paying close attention to what your Prius is doing when it comes to engine oil consumption.

Second Warning, Cleaning Your Hybrid Cooling Fan Saves Lives
If you have cats, dogs, or any other pet that can shed, beware. Pets and kids are fascinating creatures. The worst part is, they have no idea what they are doing when hanging out in your Prius. Things like hair, dirt, and other debris can find its way into your hybrid cooling fan and massively reduce the amount of airflow it is getting.

dirty toyota prius hybrid battery cooling fan

Not only will you keep your battery from failing prematurely, but you will also avoid having unnecessary breakdowns as well. It is essential as an owner to either check the fan or have it checked periodically to ensure that it is clean and working.

Third Warning, Change Your Transmission Fluid
The Toyota Prius does not have a regular transmission like you would find in any other car. It is a unique transmission that utilizes two motor generators. Unlike a conventional transmission that has far more many parts, the Prius is simple. The motor generators, are submerged in a special transmission fluid called Toyota World Standard or WS. It is non-conductive and protects the motor stator from shorting out.

Toyota WS transmission fluid

The downside is that Toyota specifies this fluid as a "lifetime" fluid that "does not need to be changed." This is one hundred percent false. That fluid, while it is rather robust, does need to be changed. It is subject to breakdown and could cause shorting faults. Generation 1 Prius has had this issue from the get-go. That is one reason Toyota changed from Type T-IV fluid to the new WS.

Changing your fluid every 60 to 90k is well worth it. If you do it yourself, you can do it for around $60 and get the OE stuff from your local dealer. Keep that transmission healthy and stay on top of your maintenance.

Fourth Warning, Change Your Filters
I recently bought a $600 Prius. It was thrashed. Now, know that not every Prius owner is like this one, but in my 15 years as a Toyota guy, I have seen a Prius or two.

I cannot say if it is something that is in the water or what, but it seems that in all my years, it was rare that a Prius owner ever came in with a clean air filter. Maybe I am just hyper-aware of my car needs. Honestly, though, between the cabin air filter and the engine air filter, they almost always needed a change.

Toyota Prius dirty engine air filter

The engine air filter is critical. Keeping all the dirt out of your engine will not only prolong the life of it but also cut down wasted fuel as well. A clean filter will also keep the MAF sensor from getting covered in dirt. Think about it, keeping your fuel trims at peak performance will keep your Prius costing you less money.

The point is, change your engine air filter. The OE one from the dealer is like $25 and should last you nearly 30,000 miles depending on driving conditions. Cheap insurance people.

Fifth Warning, Keep Your Coolant Clean
Toyota's super long life coolant is designed to have extended drain intervals. That does not mean that you can neglect it. The coolant, like the transmission fluid, is also a non-conductive. It does have a life span as well. Here is a secret though, if you want to avoid costly flushes, do a periodic drain and fill every 30 to 60,000 miles.

Toyota Prius engine and hybrid coolantThe Toyota Super Long Life Coolant comes in alternate forms. Zerex, made by Valvoline, uses the same formula at the Toyota SLLC, just for less. The issue is that as coolant ages, several things can happen. Electrolysis is a chemical reaction between metals and causes erosion. This means that all the additives that are in the coolant wear out. Once that happens, all sorts of faults can occur. Head gaskets can fail, along with water pumps and realistically, anything else the coolant touches that is metal.

Be smart, change your coolant regularly, and keep that system healthy.

I want every Prius owner to know that I care. I do not know why it took me so long to start owning a Prius, but I am delighted that I do, and that I can help others with theirs. Be sure you are not killing your Prius and get on that maintenance. If you ever need a tip or just a question answered, please feel free to reach me on social media.

Have a great week, and be sure to check out my other story, Every Toyota Dealer Should Carry This Device For Your Prius.

Peter Neilson is an automotive consultant specializing in electric cars and hybrid battery technologies. He holds a Bachelor of Science in Automotive Service Technology from Weber State University. Peter is also an Instructor of Automotive Technology at Columbia Basin College. Peter can be reached on Linkedin and you can tweet him at The_hybrid_guy on Twitter. Find his page on Facebook at Certified Auto Consulting

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Kerry ruth (not verified)    November 20, 2019 - 8:12PM

I have a 2005 Prius and all of a sudden I get the triangle of death. New batteries were installed a year ago. All filters and fluids are changed regularly too! But now it won’t go into gear? Park and neutral only with all warning lights a blaze? Any idea what may be wrong? All fuses are ok. I’ve held down info and turned on & off lights three times but nada? I’ve loved the car since new but this one has me confused!

Theodora E Foster (not verified)    June 16, 2022 - 6:47AM

Looking to buy a 2005 prius, 255,000 miles. After reading up on this, including your info, (very helpful, thanks), This last review has me concerned. Is this a good buy, need it to last at least a year.