Check Engine Light is On

stanj · Apr 20, 2020

The other day, I noticed the check engine light on for our 2013 Sonata.

I borrowed my neighbors ODB2 Scanner and checked it.

The codes are p303 (cylinder 3 misfire) and p304 (cylinder 4 misfire)

My neighbor said if the car has been sitting, and it has been due to COVID-19 stay at home orders, it may be moisture in the tank (tank is ½ filled). He said to fill it up and run it on a few trips. It may reset the codes after 3-5 starts and taking it on 8 – 10 mile trips.

Any ideas on if I need to get this to a shop soon ?

roughneck · Apr 20, 2020

I would doubt it’s sat anywhere near long enough to develop a misfire due to old fuel. Only been a month or so.
Clear the code, fill it up and give it a good hard drive.

BigJim · Apr 21, 2020

Could be a coil pack, if it is misfiring on two cylinders, swap the coils on the cylinders that are firing with the two that aren't firing and see if the other two are firing or not. If they do fire, then replace the two coils, if no change, check the plugs.

Brainbucket · Apr 21, 2020

Look in the spark plug hole to see if there is any oil. If so, you will have to replace the coil boots if the coils test good. The cause of the oil leak is valve cover gasket. Remove the oil from the hole before removing spark plugs to inspect. You don't want a lot of oil going into the cylinder. Engine damage may result.:vs_cool:

ron45 · Apr 22, 2020

Could just need a tune-up.

stanj · Apr 23, 2020

car has 114k.

We have ran it about 4 times since filling it with gas then today, my wife took it out and said the CEL light was not on.

I went out and started it and then tuned it off.

As the engine stopped and right after it stop i hear a noise up it the engine,,,video below...not sure if it is related as my wife never noticed it and i don't drive her car

roughneck · Apr 23, 2020

Not enough video to really tell anything.
Some of those little inline 4s sound like their about to blow up when they are brand new. At least to my ears.
Our old 2011 CRV was like that.

Windows on Wash · Apr 24, 2020

Does sound a bit hurt.

Another video after it idles down.

BigJim · Apr 24, 2020

The sound in the video is after the engine has stopped almost like pre-ignition. It almost sounds like something is still spinning after the engine has stopped, then what ever it is stops. Sorta like something maybe in the torq converter.

stanj · Apr 24, 2020

new audio with engine running and me standing in front with the hood up..after the engine stops, you can hear the sound

BigJim · Apr 25, 2020

If you turn the sound up, you can hear something spinning then the louder sound of when it stops. Could it be something inside of the torque converter, could it be inside of the AC compressor. Try it with the AC on and with the AC off and see if it changes. Watch the harmonic balancer and see if it keeps spinning after the engine is off. It way be built where it comes apart, but I really don't know. Check your fan blade to see if the noise is coming from there.

This has me stumped, I can't imagine what it actually can be. Check the Alternator to see if the inside is turning when the belt stops. If you do find out what it is, please don't be like a lot of people and never come back and let us know what it was.

I noticed there is a high pitched sound just before it makes the clunk sound when it stops. Something is spinning on after the engine stops. I am going with the pulley my be loose on the alternator.

Can you pinpoint the sound closer?

roughneck · Apr 25, 2020

Possibly some sort of idler issue. They can make odd sounds.

Windows on Wash · Apr 25, 2020

Doesn't sound that bad there.

Windows on Wash · Apr 25, 2020

Some of these motor will move solenoids just after the motor is shut off to clear carbon deposits. The variable vanes on my turbo go back and forth to clear the carbon so that it doesn't seize it locked in a position.

stanj · Apr 26, 2020

My neighbor knows engines pretty well,,, i can send him him the link

If I find out for sure, i will post an update ,,,also, i will listen more closely and look for where the sound is coming from

stanj · May 3, 2020

I tried to narrow down the place the sound is coming from,,
Not sure, but may be near the fan belt or alternator,,

It is hard to do it alone, but i may try again

Windows on Wash · May 4, 2020

That is some sort of solenoid after the engine is off. If the car is a turbo equip, it is likely variable vane and that could be the solenoid for the vanes cycling to clear it of carbon.

Brainbucket · May 4, 2020

Sounds like drive by wire throttle body sweeping after engine shut off. Other cars do it. Normal.:vs_cool:

Check Engine Light is On

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