Radiator problems of the 2011 Hyundai Sonata

On March 1, 2021, I noticed an odd smell while idling in line. Turned car off until it was my turn. The smell was gone once I turned it back on, so thought it was another car and drove to work. That evening, smell started again after driving a few miles to parent's house. Parked the car at parent's and arranged to drive it to mechanic the next morning after having my father confirm there was water in the radiator and the oil wasn't too low. Engine temp gauge was normal. Check engine light was on, but had been for the length of time I had car. I had it checked several times- issue would be supposedly found, but it would always come back on. I was led to believe it was a faulty sensor issue. There was nothing obviously wrong when we looked under the hood and had no reason to think it would not be safe to drive the short distance to the mechanic. Next morning, March 2, 2021, I intended to drive the car to the shop so they could address the issue causing the smell, and father followed behind. Car seemed fine at first, but after a couple of miles driving on surface streets, the smell came back. Pulled over and turned off car, thinking that I would need to have the car towed the remainder of the way. I saw something come from under hood. My father, who had been following behind, asked me to pop the hood. As I climbed back in the car to pop the hood, I realized there was smoke inside the car. I got out, told my dad that there might be a fire as there was smoke inside the car. As we had that discussion, smoke started pouring from under the hood, and we backed away from the vehicle and called 911. Within seconds, there were visible flames and the whole front of the vehicle was engulfed in flame. Today, March 10, 2021, I was made aware that 2011 Hyundai Sonatas were included in a list of vehicles known to catch fire, so I am filing this notification.

Bought car 4/2017 5 days later engine locked 4/2017 replaced by Hyundai under warranty and received back 5/2017. Was driving started smelling antifreeze, car never showed overheat, pulled over, it blew radiator cap off, bought new cap, went back to car, added fluid and cap, drive 1/10 of a mile and car cut off and would not start back. My mechanic picked up and reports water in engine and metal in oil. Same as first engine. Hyundai claims no warranty on this new engine. This engine has metal in oil the same as their recall.

After having the engine replaced under recall campaign 132 and 162, the engine oil cooler failed allowing hot motor oil to mix with engine coolant. This in turn caused most of the rubber piping to become distended, causing them to have to be replaced. Also, the radiator system needed to be flushed more than once because of the difficulty in vacating the motor oil from the system. My vehicle's water pump needed to be changed a few months later, due to it failing. A private mechanic stated that this was more than likely due to the hot motor oil mixing in the system, causing the seals on the water pump to fail. I reported this problem to the Hyundai dealership, as well as Hyundai corporate, and they both stated that this problem was not covered under the recall campaigns. I believe that the failure of the oil cooler and water pump is directly correlated with the replacement of the engine, and my private mechanic has stated the same. My vehicle was in motion on a highway when these parts failed, and if I continued without pulling over, it is highly likely that the engine would have caught fire or seized.

The thermostat housing is plastic molded over a steel (metal) core. Where the housing is bolted to the engine over the input and output coolant orifices an internal piece of plastic flaked off the steel core behind the gasket surrounding the input orifice. At rest no coolant leaked out of the cooling system. However, at operating temperature and pressure, the coolant sprayed out of the engine in a fine mist/spray. Although there was an odor of coolant while driving, all searches around the heater core, under vehicle resulted in no evidence of coolant leak. On an extended trip at 103,000 miles enough coolant evacuated the cooling system to facilitate a blown head gasket. Yet there were no warning lights indicating overheating. The blown gasket was discovered when there was a sound of gurgling liquids originating from the coolant reservoir when we reached our destination, a thick sludge of coolant and oil permeated throughout the engine, heater core, throttle body and radiator. It was during repairs the thermostat housing was found to have the interior damage. If we had been driving 30 miles further than we did, the engine would have seized at highway speed, undoubtedly causing an accident. Thank god we stopped when we did.

I was driving down the highway, the engine started making a knocking noise. No less than 30 seconds later did the car's engine make a large bag noise and I ran over what felt like parts. I coasted a while down the road and finally pulled the car over to the side of the road. Upon opening the hood I discovered oil all over the intake and exhaust manifolds as well as the radiator. I called Hyundai roadside assistance and had the car towed to faulkner Hyundai in harrisburg PA on 1/19/14. They provided a service loaner and said they would get back to me with an update on the car. I waited until Wednesday the 21st before calling them, only to find out that the engine had seized and they had already taken pictures of the damage and sent them to the Hyundai people to seek warrantee coverage. They also asked me for maintenance records on the car. I change the oil myself and always put in full synthetic, so they had me submit receipts from the auto parts store proving I bought oil and filters or the Sonata. I am now awaiting resolution from Hyundai. Will update once I have an answer from Hyundai. This is a pretty serious safety concern, the engine let go at 60+mph without warning, when it let go it blew oil all over the engine compartment and I'm sure on the road as well. Lucky I was driving early in the morning and their was very little traffic.