Misfire P0304 every 3 months

[sonatablues23]

Hello,

I have a 2017 Hyundai Sonata. Every 3 months the car starts misfiring and I get a P0304 error code. This first happened on Feb 4th. I took it to a mechanic and he said it was a bad spark plug, so I replaced all 4 and the car was fine.

Then the same issue happened again on May 10th. I got the same P0304. This time the mechanic said it was a bad coil - he said if he moved the coil the problem followed the coil. After replacing the coil everything was fine again, no issues on all

Today, Aug 4th, almost 3 months later again, I have the same misfiring and P0304 issue. I find it odd that this happens almost exactly every 3 months. I am trying to find another mechanic to look at it.

A couple days ago I got a letter from Hyundai saying the warrenty for the fuel pump filter assembly has been extended to 15 years/150,000 miles. I called a few Hyundai dealers but they are booked until Oct because a new round of warrenty claims for the security issue. Do you think my P0304 issue could be cause by a bad fuel pump assembly? If someone other than a Hyundai dealer fixes it could it be covered?

Thanks

 

[sonatablues23]

Update: I took my Sonata to another mechanic and he said the spark plug in cylinder 4 had oil on it, it was only 3 months old. The cylinder 4 plug has oil caked on, possible valve seal failure or piston ring failure. He said I need my engine needs to be replaced. He also told me replacing the spark would temp resolve the issue, but eventually I would have the issue again until the engine was replaced. That's exactly what I have been seeing. I did some research and found Hyundai's like mine have a known issue with consuming too much oil, slow acceleration, and issues with the rod bearing. My car has a update installed to tell me if there's a issue with the rod bearings - so far no issues, however when my car is running I can hear the pistons, they seem to loud. My issue seems related to the known Hyundai engine issues

I just dropped off my 2017 Hyunda Sonata with 62,000 miles at a dealer. The "service advisor" told me like 20 times they wont cover a new engine. I had to ask several times for them to just look at the car. This looks like a fight. Can anyone in this situation give me advice on how to make sure Hyundai covers this issue? I have taken care of the car very well, and i have all receipts showing I got oil changes every 6,000 miles. This is a defect in the car, and nothing to do with maintenence or how I drove it. It looks like I'll have to contact corporation or join one of the many class action lawsuits against Hyundai. Anyone have any advice so the dealer takes this more seriously, instead of blowing me off?

Thanks