Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2018 Chevrolet Volt owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2018 Chevrolet Volt. The contact stated that while driving at an undisclosed speed, the vehicle lost automotive power. The check engine warning light illuminated. Shortly afterward, the message "Reduce Propulsion, Engine will not Start" was displayed on the instrument panel. The vehicle was towed to a local dealer where it was diagnosed with a defective EGR valve. The contact was informed that the EGR valve needed to be replaced. The vehicle was not repaired due to the cost and lack of parts availability. The vehicle was towed to the residence. The contact believed that the cause of the failure was related to high temperatures. The manufacturer was made aware of the failure. The failure mileage was approximately 69,000.
The contact owns a 2018 Chevrolet Volt. The contact stated that the battery module became inoperable. While attempting to start the vehicle, the message "Engine Unavailable - Service Soon" was displayed. The contact was unable to use the vehicle. The contact stated that the TPMS warning light was illuminated. The contact associated the failure with Technical Service Bulletin: 18-NA-261. The contact called the local dealer and was referred to the manufacturer for assistance. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed that the VIN was not under recall. The failure mileage was approximately 111,000.
The contact owns a 2018 Chevrolet. The contact stated that on several occasions while driving at various speeds, the vehicle lost motive power with the check engine warning light illuminated. The vehicle was steered to the side of the road and restarted each time, but the failure persisted. The vehicle was taken to the dealer where it was diagnosed that the EGR valve needed to be replaced and 40 unknown DTC codes had been retrieved. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 55,000.
The contact owns a 2018 Chevrolet Volt. The contact stated that while his wife was driving 60 MPH, the message "Power Reduced" was displayed. The vehicle was taken to an independent mechanic who determined that the failure was due to the EGR valve. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 51,000.
EGR valve failure at highway speed of 70mpg on busy road with passenger and service dog in vehicle on a road trip (on ICE not electric). This produces a reduced propulsion in the vehicle and it becomes unsafe to drive. The EGR failure blew the 15A #3 fuse known as the "no walk home" fuse, so I needed to be towed to a parts store then unplug the EGR valve to make it somewhere safe. It was a Sunday, so every dealership (in the VA area at least) was closed. It is a well known/documented issue and the warranties have been extended, but only in a few states with the CARB protections. There are no warnings, if I was not an adept driver, we could all be dead. I also became stranded ~six hours from my home and only ~eight thousand miles outside of warranty. …
The dealer reported having repaired an emissions recall for a fuel vapor leak, however the repair was ineffective and the vehicle still reports the leak as a fault code "slow" and "fast" emissions leak. The dealer refused to recheck their work without payment. Recently I came into possesion of a borescope camera and was able to photograph the dealer's "repair". The photos clearly show the parts for the emissions repair are located in the wrong place as compared with GM's own service bulletin. Therefore the dealer did not do the repair, or failed to do the repair, and refused to check there own work without compensation when informed of the continuing problems and left me to do their recheck of their work at my own expense. I have provided photos of the GM prescribed parts placement and the incorrectly placed parts in my car as well as the resulting damage. …
I was driving back from [redacted] on [redacted], when I received a "propulsion power limited" message on my dash with a check engine light. I pulled off to a nearby gas station and tried to scan the code to figure out what was going on when I then received the message "Engine unavailable" and the car shut off. I checked the fuse box and found that the F03 Fuse had blown. I replaced the fuse and attempted to start the car again. It began normally, but then after driving 10 feet, I received the "engine unavailable" message again with a check engine light and the car no longer had power and I had to coast into a parking spot. I checked the fuse again and found it was blown. If I had not stopped in the gas station, I would have been stranded on the side of the highway, or worse yet, I would have stalled out on the highway and potentially got hit. …
On 8/30/2024 I had driven my 2018 Volt (purchased new on 3/27/2019), with about 45,000 miles on it, on a normally 5 hour trip. About 3 hours into my trip on I-94 my car suddenly slowed down with a "Reduced Propulsion" message and a check engine light that came on. (The engine probably has run less than 25,000 miles of the total miles I have driven it, with the rest being purely on battery.) I was extremely fortunate to have been in the slow lane when the car suddenly stopped accelerating. This could have easily turned out very, very bad. The next day I had a dealer diagnose the car for a little over $400 - they told me there was a problem with my engines EGR valve and that the parts were back ordered so they couldn't give me an indication of when it could be repaired. …
The Battery Energy Control Module needs to be replaced (BECM). The car is available to be inspected at Key Chevrolet in South Burlington, VT. The car was parked when it failed. The car wouldn't start (lights on the dashboard came on) and it wouldn't turn off. I got a "shift to park" error message, regardless of which gear I was in. The car wouldn't go into Drive to go forward with either the drive battery or the gas generator. I had the car was towed to the dealership. It was inspected and diagnosed by them. When they did the diagnosis, they said the BECM had failed and there were cells in the drive battery that needed to be replaced. The BECM failure is a common problem with Chevrolet Volts and is covered by the Voltec warranty. There were no warning lights or other warnings (e.g., reduced propulsion) whatsoever. …
While driving on a highway the car started to hesitate, a message appeared on the console "Propulsion power is reduced" and the engine light turn on. After driving some miles, a new message appeared: "Engine unavailable, service soon" and the car only ran on electric power, no motor engine. I had the same problem 3 year ago and the dealer identified the problem as a shorted EGR valve. This time I knew this shorted EGR valve burns the F3 fuse. I managed to get to a car part shop and bough several fuses (15 amp). After replacing the fuse 3 times I managed to get to the dealer. The repairs cost $3000+ (up from $1000+ 3 years ago). This problem is well documented on the GM service technical bulletin "21-NA-116" dated February, 2023. …
Engine complaints in other Volt years
Frequently asked questions
How common are engine problems on the 2018 Chevrolet Volt?
NHTSA has 51 complaints about the engine & cooling of the 2018 Chevrolet Volt, 23% of the model year's 225 complaints. The component named most often is exhaust system › emission control › gas recirculation valve (egr valve) (2 mentions).
Is there a recall for 2018 Chevrolet Volt engine problems?
No. NHTSA lists no engine & cooling recall for the 2018 Chevrolet Volt, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2018 Chevrolet Volt engine problems start?
Half of the complaints with a recorded mileage happened before about 51,000 miles, and 44% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.