2018 Kia Optima · symptom sheet
Burns oil or oil level rises
- 48owner reports
- 45,000median miles
- 0involved a crash
Newest report Jun 25, 2026 · checked Oct 2, 2026
149 of the 232 complaints on this car are about the engine. 48 of those describe oil consumption. Only engine failure is reported more often on this car.
Tick what matches of 48 reports
Oil consumption on other Optima years
Report counts are for each model year on its own, so a newer car has had less time to collect them. Model years with too few reports of it for a sheet: 2014.
What this problem usually is
Two different complaints land here. The more common one is an engine that uses oil: owners add a quart between changes, get a low-oil warning, or are told by the dealer that the rate is normal. The other is the opposite, where the oil level climbs and the oil smells of gasoline. Both deserve a proper test, and both are easier to argue with records in hand.
What got replaced
Owners who name the part that was replaced mention the piston rings (14 reports) and the engine (4 reports).
Recalls and investigations
No recall on the engine covers the 2018 model year as of Oct 2, 2026.
NHTSA investigations into the engine on the Optima
Loss of motive power. Closed dec 12, 2023.
Engine fires. Closed feb 5, 2024, led to recall 23V-877.
Scope and timeliness. Closed dec 22, 2021, led to recall 17V-224.
When it happens
The middle half of failures fell between 1,000 and 98,000 miles, from the 23 reports that gave a mileage.
Is this a known problem?
The manufacturer has sent NHTSA 4 service bulletins or notices for the 2018 Kia Optima that deal with this problem. Newest first.
Federal rules make a manufacturer send NHTSA a copy of any notice about a defect that goes to more than one dealer or owner. Most of these are service bulletins, the repair instructions manufacturers send to dealers. NHTSA generally leaves safety recall bulletins out of this file, and recalls are listed separately.
EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES This bulletin provides information on diagnosing and/or repairing some 2011-2024MY vehicles (refer to the table on pages 9 and 10 for applicable models and engine), which may exhibit a symptom of excessive oil consumption.
EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES This bulletin provides information on diagnosing and/or repairing some 2011-2021MY vehicles (refer to the tables on pages 8-9 for applicable models and engine), which may exhibit a symptom of excessive oil consumption.
EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES This bulletin provides information on diagnosing and/or repairing some 2011-2019MY vehicles (refer to table below for applicable model and engine), which may exhibit a symptom of excessive oil consumption.
EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA ENGINES This bulletin provides information on diagnosing and/or repairing some 2011-2019MY vehicles (refer to table below for applicable model and engine), which may exhibit a symptom of excessive oil consumption.
What owners wrote
“Iâve had my car for 6 months and it constantly burns oil Iâve had 4 oil changes because it Is completely disappearing but my mechanics can not find any leaks. Then I changed all my spark plugs and two were completely burnt and they were changed a month ago and now one of them went again and this time is completely covered in oil”
Filed Oct 7, 2025
“The engine of my 2018 Kia Optima is burning oil. When it started, I had 72,000 miles, and it's burning one quart of oil every thousand miles. There is no oil leak. I will take it back to Kia on October 2, 2025. The mechanic reported that it has an internal engine issue.”
Filed Sep 28, 2025 · 72,000 miles
“The oil consumption is burning at a faster rate than normal. My oil changes are always on time but for months I have been having to take it for an oil change about 2,000 miles below mileage time. I have had it inspected but found no oil leaks. This is a major problem for the engine and safety.”
Filed Sep 24, 2025 · 2,000 miles
“Excessive Oil consumption. Manufacturer specs 1 quart of oil to every 1000 miles to be added. I'm adding 1 quart for every 500 miles. Advised kia and had oil consumption test and was told nothing is wrong. I am having to add extra oil 0so engine does not seize causing a safety issue for people in car. The car randomly spits smoke out.”
Filed Oct 11, 2023 · 1,000 miles
Should you keep driving it?
This page can't tell you that. 0 of 48 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.
File your own report with NHTSA. Complaint counts are how a problem gets an investigation. How reports land on this sheet.
Guide Taking it to a shop? How to describe this problem so it gets found
Other problems on this car
- Engine failure, knocking or rod bearing 52 reports
- Check engine light or misfire 37 reports
- Engine stalls or loses power while driving 34 reports