2018 Kia Niro Problems and Top Complaints – Is Your Car A Lemon?

Updated on August 17th, 2023 Author: Brian Jones

The 2018 Kia Niro is a hybrid crossover that took the market by storm, thanks to the exceptional fuel economy and low starting price. The automaker even claims that new Niro models provide “miles of style,” but owners would be happy to get functionality out of this crossover. It suffers from a defective electrical system, malfunctioning powertrain, non-effective service brakes and a poorly-built structure.

Click on other model years to view more problems: 2019   2020   2021   2023

NHTSA Complaints for the 2018 Kia Niro

Problems with the Electrical System

With the right electrical system in a vehicle, everything runs like clockwork, but that’s not the case with this Niro model. The system is downright glitchy and causes numerous problems.

One Cars.com review states, “We bought a new Niro in June 2018. Since purchasing this car, we have had issues with the car’s computer system, shift lock malfunction, and door handle falling off the vehicle.”

Among these problems, there’s a large issue that owners must know about. NHTSA Campaign Number 18V666000 affects more than 27,000 vehicles and states that the increased electrical resistance at the main relay can lead to a fire. This relay is found below the rear seat, further putting occupants at risk. While it might provide plenty of style for those miles of travel, it might not make it for the journey, especially if it burst into flames first.

Problems with the Engine

The Niro has a hybrid setup, which utilizes some electrical components in conjunction with the engine. It’s already been proven that the electrical system is sub-par, but it’s even worse when looking at the motor defects.

One Edmunds complaint says, “Had to trade car after a month of owning it. I had a major horrible scare with my Kia Niro within the first few weeks of owning with a very strong gasoline and burning plastic smells in the cabin of the car. First I thought that maybe I spilled gas on myself, but no, it was coming out of the vents each time I either ran the AC or heat didn’t matter what setting you had it on it was bad. Along with the gas smell there was also a burnt wire/plastic smell which was so bad I was expecting to see smoke or flames coming out of the vents or hood, it never did thankfully. Both smells made me completely nauseous and sick each time I had to drive the car I had to put the windows down to feel better. I felt so uncomfortable in the car feeling this sick. Dealership said nothing is wrong with the car but then Kia’s have had fires in other models so it worried me that it could of happened with that KIA.”

This is a situation that no car owner should have to face. It appears that the automaker is dealing with countless other engine issues on top of this. In fact, Service Bulletin #TSBELE161 talks about the OBC inlet hose detaching and causing a coolant leak. To fix it, technicians must install a spacer. Overall, it’s evident that the Niro can’t move to travel all those “miles.” Between leaking coolant and potential fire, this car might spend more time breaking down than actually moving.

Problems with the Transmission

Even on a hybrid car, the transmission is responsible for a smooth-shifting experience. Without this, owners just get frustrated and irritated, which is precisely what happens with the Niro.

Examine this Cars.com review as one example. “First thing I noticed was the transmission on this car. It’s hard to miss that because it acts weird in slow speed. Like it’s confused on which gear it needs to be. When you need that power, it doesn’t downshift on time and it’s so annoying. It’s like turbo lag!”

Sadly, Kia decided not to discuss any powertrain issues, but that doesn’t mean that this car is perfect. In fact, it’s more likely that the automaker doesn’t want to draw any more attention to the trouble this vehicle creates. Instead, Kia wants people to believe that this hybrid will travel “miles,” but most drivers can’t trust it any longer. Staying close to home is the best solution when heading out, just in case.

Problems with the Brakes

A look at the service brakes on the 2018 Kia Niro reveals some dangerous situations. With all the other defects, it would be nice to have a quality set of brakes, but that must be too much to ask.

One NHTSA complaint states, “Car failed to stop twice – almost ran a red light. Brakes depressed and felt no pressure in brake line. Dealership has fixed brake issues with car only being 6 months old in 2018 – same brake issues but now the car is not stopping sometimes.”

Kia was sneaky when talking about brake concerns. Instead of being open and honest, the company issued Service Bulletin #TSBCHA086 that discussed the need to listen to customer concerns. The automaker claims that it is trying to figure out if updates need to be made to the braking system to improve the customer experience. It doesn’t take a rocket scientist to figure out that these problems should be repaired immediately. Unless Kia would rather force the Niro to travel those “miles of style” by keeping it from stopping.

Problems with the Vehicle Structure

No one expects the Niro to be constructed with luxury materials. After all, it is a lower-priced hybrid option. However, it shouldn’t be falling apart.

That’s exactly what this NHTSA user claims is happening. “A few months ago, the front passenger door handle fell off when trying to open the door when the car was parked/stationary. The vehicle was taken to the dealership, and the handle and cover were replaced. Today, 10/22/2018, the right rear passenger door handle popped off when trying to open the door when the car was parked in the driveway. Both times the doors were unlocked, and the pressure applied to the door handle was minimal (normal). The handle broke in the same place as the first. When contacting the dealership, we asked if the other handle (right rear passenger) could also be replaced, as this seems to be a defect. The service department said that they could inspect it when replacing the other handle, but could not order parts until it is determined that it is broken.”

Kia hasn’t been quiet about this problem either, even issuing Service Bulletin #TSBBOD173_R1. Technicians are permitted to replace all three outside door handle covers because of separation caused by a defect in manufacturing. If the door handles break, it might be for the best. After all, if owners can’t get inside, they might be safer than on the road behind the wheel of the lemon Niro.

Your Lemon Law Legal Rights

Think you have a lemon? Sit back and let the experts work out your lemon case at no cost to you. The law makes Kia pay legal fees. You may be able to get your lemon out of your life. Every year, auto manufacturers buy back, replace or pay cash settlements to thousands of ‘lemon’ owners like you.

About the Author:

Brian Jones spent more than 30 years working as an ASE Certified Master Tech and Parts Specialist at multiple dealerships. Brian has become an authority in the industry, traveling across the country to consult for car dealerships and contributing his expertise as a writer for several major automotive publications. In his spare time, Brian enjoys working on pickup trucks, muscle cars, Jeeps and anything related to motorsports.

See more posts from Brian Jones