TECHNICAL SERVICE BULLETIN: REPLACEMENT OF MOBIS C-MDPS SMALL BEARING - This bulletin provides the procedure to replace the small bearing of the Column Motor Driven Power Steering (C-MDPS) unit on the vehicles listed below, which may exhibit an abnormal noise when steering left and right. This may be caused by foreign substances in the MDPS worm shaft small bearing. On some vehicles when the steering wheel is rotated a scraping noise can be heard originating from the lower bearing on the Worm Gear Small Bearing and does not affect the steering effort.
full bulletin at NHTSA ↗2018 Kia Optima steering problems
moderate Owners of the 2018 Kia Optima have filed 12 NHTSA complaints about the steering at roughly $700 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See steering across all vehicles →
Complaints
12
Recalls
0
Avg fix
$700
| Model year | steering complaints |
|---|---|
| 2014 Optima | 94 |
| 2015 Optima | 68 |
| 2016 Optima | 24 |
| 2017 Optima | 11 |
| 2018 Optima (this page) | 12 |
| 2019 Optima | 6 |
When does it fail?
Of the 12 steering complaints filed for the 2018 Kia Optima, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering steering on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
TECHNICAL SERVICE BULLETIN: PARTIAL REPAIR OF C-MDPS MOTOR, ECU, WORM GEAR AND/OR STEERING COLUMN HOUSING - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information regarding the partial repair of the Motor Driven Power Steering (MDPS) Motor, Electronic Control Unit (ECU), Steering Column Housing, or Worm Gear Assembly. When the steering wheel is rotated a scraping noise can be heard originating from the lower bearing on the Worm Gear Assembly on some 2010MY~ Kia models listed on page 8, equipped with a Column Motor Driven Power Steering (C-MDPS) unit. On some ve
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: PARTIAL REPAIR OF THE DUAL PINION MOTOR DRIVER POWER STEERING SYSTEM - This bulletin provides information regarding the availability of partial repair (depending on faulty components) of the Dual Pinion Motor Driven Power Steering (DP-MDPS) system on some 2016-2021MY~ Kia vehicles (refer to the table below) in order to enhance customer satisfaction by promoting a cost-effective repair/replacement of a faulty related part, instead of replacement of the complete DP-MDPS assembly.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: PARTIAL REPAIR OF C-MDPS MOTOR, ECU, WORM GEAR AND/OR STEERING COLUMN HOUSING - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information regarding the partial repair of the Motor Driven Power Steering (MDPS) Motor, Electronic Control Unit (ECU), Steering Column Housing, or Worm Gear Assembly. When the steering wheel is rotated a scraping noise can be heard originating from the lower bearing on the Worm Gear Assembly on some 2010MY~ Kia models listed on page 8, equipped with a Column Motor Driven Power Steering (C-MDPS) unit.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: PARTIAL REPAIR OF C-MDPS MOTOR, ECU, WORM GEAR AND/OR STEERING COLUMN HOUSING - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information regarding the partial repair of the Motor Driven Power Steering (MDPS) Motor, Electronic Control Unit (ECU), Worm Gear Assembly or Steering Column Housing on some 2010MY~ Kia models listed on page 8, equipped with a Column Motor Driven Power Steering (C-MDPS) unit.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 12 complaints center on electric power steering failures tied to engine stalling events. Owners describe the steering wheel suddenly becoming hard or impossible to turn, often while multiple warning lights illuminate (EPS, ABS, ESC, battery, master malfunction). In several cases, the engine dies completely during these incidents, cutting off all power steering and brake assist—leaving drivers with only manual steering and mechanical brakes while moving.
The failures happen unpredictably across a mileage range from 22,500 to 63,826 miles. One owner reported losing all electrical power mid-drive on a city road shortly after routine maintenance; another lost steering control while parking with four children in the vehicle. A third owner had steering lock up mid-turn at highway speeds with the EPS warning light on.
When owners take their cars to dealerships, technicians consistently claim they cannot recreate the problem and decline to perform repairs. One owner was told the only way to fix it was to leave the vehicle for an extended period hoping the failure would happen again.
One complaint describes a steering column coupler failure requiring full steering column replacement ($1,200+) when the coupler itself costs $12. The owner notes similar Kia models received recalls that didn't apply to theirs.
A separate concern: one owner states the steering wheel does not lock when the ignition is turned off and the key removed.
Same Kia Optima steering reports on nearby years: 2015 · 2016 · 2017
Failure modes owners describe
Electric Power Steering (EPS) Loss with Hard Steering
The electric power steering system fails abruptly, causing the steering wheel to become difficult or impossible to turn. This occurs with or without warning and can happen during routine driving. Multiple dash lights illuminate simultaneously (EPS warning, ABS, ESC, battery charge, master malfunction), and the failure is often accompanied by engine stalling. Several owners report the steering goes completely unresponsive, forcing them to coast to a safe spot.
When: Various mileages from 22,500 to 63,826 miles; incidents occur during low-speed maneuvers (parking, reverse) and highway driving
Symptoms owners cite: Steering wheel becomes hard to turn or locked; Electric power steering warning light illuminates; Multiple dashboard warning lights (ABS, ESC, battery, master malfunction) flash simultaneously; Loss of steering control mid-maneuver; Engine stalls during steering failure; Clicking sound when attempting restart after stall
Codes mentioned: EPS warning light
Repairs/costs cited: Dealers unable to reproduce the issue in most cases and decline repairs. One owner reported being asked to leave vehicle for extended period to duplicate failure.
Engine Stalling with Power Loss
Complete loss of engine power and electrical system function while driving, resulting in vehicle shutdown. When this occurs, power steering and brake assist are lost simultaneously, leaving the driver with mechanical steering only and no braking assistance. This creates an immediate safety hazard, particularly in traffic.
When: Occurs after routine maintenance or without warning; reported at 22,500 miles and after oil changes
Symptoms owners cite: Engine sputters shortly after leaving dealership for maintenance; Vehicle completely powers down while driving; Loss of power steering when engine dies; Loss of brake assist when engine dies; Vehicle will not crank on first attempt; requires jump start; Multiple dashboard lights illuminate before stall
Codes mentioned: Check engine light (flashing in one case)
Repairs/costs cited: Dealership unable to recreate the issue; vehicle returned to owner unrepaired in multiple cases.
Steering Column Coupler Failure
The steering column coupler ($12 part) fails, making steering dangerous. Because the part cannot be replaced in isolation on this vehicle, the entire steering column assembly (over $1,200) must be replaced.
When: Not specified in narrative
Symptoms owners cite: Steering becomes unsafe to operate
Repairs/costs cited: Steering column coupler failure requires replacement of entire steering column assembly at cost exceeding $1,200; comparable Kia models were recalled but not this one
Recalls/TSBs owners mention: Some models recalled but not this vehicle
Steering Wheel Lock Mechanism Failure
The steering wheel does not lock in the parked position when the ignition is turned off and the key is removed, creating a potential theft and safety concern.
When: Not specified
Symptoms owners cite: Steering wheel does not lock when vehicle is parked and key removed
Intermittent Steering Wheel Stiffness
Steering wheel becomes temporarily stuck or stiff on startup. Turning the engine off and back on restores normal steering function.
When: Not specified
Symptoms owners cite: Steering wheel locked or stuck at engine startup; Returns to normal function after engine restart
Synthesized from 12 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 4 most recent
Steering column coupler went bad. Unable to swap out the coupler alone ($12 part) and had to get a whole new column (over $1200). Some of the Kia's around this one's make and model were recalled but not this one. Without this repair driving would have been dangerous.
We would like to know what Kia is planning to do to address the fact that Kia built a car without the basic immobilizer circuit making it very easy to steal. Over the last few months, local and national news reports, as well as many social media sites, have reported on this security flaw which likely emboldens others to attempt a theft of a Kia and/or Hyundai. As I do not live in Milwaulkee, I…
I have 63,826 miles on my 2018 Kia optima s and I drove it to the store and all my light on the dash came on when I would come to a stop and my power steering would go out and about cause me to wreck. I was told that it was my alternator but after getting a new alternator I then drove it to get dinner a few days later when the same thing started happening again and my power steering kept going…
I have never had any issues with my car, I get maintenance as scheduled so it's odd that this is even happening. On december 6th I went to move my car. I crank the car with no problem. I noticed it kind of hesistated slightly, but continued on with no problem. When I went to put my car in reverse in order to park it stalled and about 5 or 6 of the lights on the dash came on, the steering wheel…
Had steering trouble with your 2018 Kia Optima?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the steering problem on the 2018 Kia Optima?
It's a documented issue but not catastrophic. 12 complaints have been filed. Repairs average $700 and most owners catch it before it causes a breakdown.
At what mileage does the steering typically fail?
Based on the 12 complaints filed, steering issues most often appear around 44,489 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $700 for steering repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to steering?
No active recalls currently cover steering issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2018/Kia/Optima.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.