Multiple misfires and White smoke


New member
Genesis Model Year
Genesis Model Type
Genesis Coupe
Hello everyone! I am Zambee and I have a 2010 genesis coupe 3.8 6 speed manual. It has a 165000 mileage.

I think i need help to fix my car. So, my car starts to make a thick white smoke and the check engine light came on and code p0300 (detected multiple misfires).

This is what I’ve done.

I changed the spark plugs and oxygen sensor.
I swapped the injectors. But misfires are still there.

I already opened the cylinder head/head gasket and found out a coolant mixed to the oil in the cylinders. So I found out that there was a coolant leak coming from the “little 2 holes towards the cylinders.
I have no idea what its called but PICTURE attached below. So basically if you take that thing up “head gasket “ , there are 2 little holes you see in there where the coolant is.

Also, the manifold intake has oil inside but I already cleaned it out.
One more thing, i tried to suck the PCV valve and it worked but when I did blow it out the PCV valve was stuck. (Im thinking that theres no air pressure pushing down the oil or idk much about it).

Please help me out
I appreciate all your help. Thank you!




Registered Member
Genesis Model Type
Genesis G70
I replied to your first thread on this.
I'm a little confused, did you replace the head gaskets? Your picture doesn't show the head being off. The symptoms you describe are classic head gasket failure. Otherwise there must be a crack in the head, or...?
How many cylinders had coolant in them?
Once you find and fix the problem, be sure to change your oil and filter, obvi.
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