TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - 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 relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, and the transmission oil cooler is transferred to the new transmission.
full bulletin at NHTSA ↗2018 Kia Forte powertrain problems
severe Owners of the 2018 Kia Forte have filed 8 NHTSA complaints about the powertrain at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Complaints
8
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2014 Forte | 16 |
| 2015 Forte | 17 |
| 2017 Forte | 11 |
| 2018 Forte (this page) | 8 |
| 2019 Forte | 46 |
| 2020 Forte | 15 |
| 2021 Forte | 7 |
1crash
What stands out
No new NHTSA powertrain complaint has been filed on this vehicle in over 6 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain 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.
This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: TRANSMISSION FLUID APPLICATION GUIDE - This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, refer to applicable vehicles in the chart starting on page 2.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: 7-SPEED DCT JUDDER INSPECTION AND DUAL CLUTCH ASSEMBLY REPLACEMENT - 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 the procedure to replace Dual Clutch Assembly and upgrade the TCU on some 2016-2020MY Kia vehicles listed in the table below, equipped with the 7 Speed Dual Clutch Transmission (DCT), which might exhibit clutch judder when accelerating from a stop.
full bulletin at NHTSA ↗TECHNICAL SERVICE BULLETIN: - TRANSMISSION FLUID APPLICATION GUIDE - This bulletin has been revised to include additional information. This bulletin provides information relating to the correct transmission fluid type and fill quantity requirement for each Kia model. A flush is required ONLY when a transmission is replaced, refer to applicable vehicles on page 2. Refer to the shop manual on KGIS for the specific Kia model for the correct transmission fluid check/fill procedures.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 1 most recent
Ive had my car since 38 miles. This is my second year owning it. It has been well kept and it started having problems about a month ago that has gotten worse. It shakes really bad at 30mph and stays in 6th gear. It also has major problems picking up speed and shifting in general. Sometimes it just stalls and dont go. When switching lanes on the interstate it slows way down and doesn't shift. It…
Had powertrain trouble with your 2018 Kia Forte?
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 powertrain problem on the 2018 Kia Forte?
It's a meaningful issue. 8 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Based on the 8 complaints filed, powertrain issues most often appear around 64,540 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 $2,500 for powertrain 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 powertrain?
No active recalls currently cover powertrain 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/Forte.
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.