EGR Valve or worn valve seals

[t-dog]

2009 Hyundai Genesis 3.8 was told by my dealership that the valve seals are worn on my vehicle. If they are worn out, would they affect the compression on a cylinder leak test and would I see oil burning through my exhaust? OBD code P0305 showing (Cylinder 5 Misfire). No oil burning visible. Check engine light is on (solid) but if it starts flashing vehicle starts shaking and loss of power is experienced. If I shut off the car and re-start, problem disappears but check engine light stays on (solid). Problem exists only on idle but never when driving. Guessing that it may be a faulty EGR valve or other valve being plugged and not valve seals. Where the EGR valve is located on this vehicle. Have tried changing plugs, switching plug coils with a different cylinder, cleaned throttle body, checked for intake leaks. If valve seals are worn, is there valve seal conditioners that may help and what brand do you recommend? Had also read that the car has a purge valve, would there be any bearing on the rough idle through this valve?

 

[homeofstone]

Have the valves ever been adjusted? It has solid lifters. Also is the engine still under 100k miles warranty?

 

[t-dog]

No, warranty has long expired, sitting at 124k miles. Don't know too much about newer vehicles but are valves still adjustable or are they all controlled by all the computers nowadays?

 

[Mark_888]

No, warranty has long expired, sitting at 124k miles. Don't know too much about newer vehicles but are valves still adjustable or are they all controlled by all the computers nowadays?

I believe that they are adjustable on the 3.8L. the Owners Manual says that Valve Clearance should be inspected every 60K Miles on the 3.8L engine "for excessive tappet noise and/or engine vibration and adjust if necessary." This does not apply to the 4.6 or 5.0L engine.

 

[t-dog]

If the valve was off and needed adjustment, wouldn't the car shake continuously? What happens is the car sits at idle then stumbles and shakes after a few minutes, the check engine light starts flashing. But if I shut off the car and re-start it everything goes back to normal until the next time I sit at idle. Is it possible that there is carbon built up or valve damage? Your thoughts?!? Really trying hard to avoid pulling the head off.

 

[Mac West]

Its a bad coil pack. When the light flashes thats when it is misfiring . Mac