2010 R56 with 104,000 miles and an N12 manual engine started running rough at idle with no codes initially. Code came up after 2 days: p0303 cylinder #3 misfire. I'm not sure if the plugs had been changed in the past. The ignition coils have maybe 25,000 miles on them. Bought some new spark plugs to see if it would be an easy fix. I bought these:



When I pulled the ignition coils off, all the cylinders were clean except the #1, which had oil. (Perspective looking down at the spark plug)



Next is the #2 cylinder, (the #3 and #4 cylinder look identical):



So, I figure I'd buy a new valve gasket thinking there is a leak in the #1 cylinder tube gasket. I bought this one:



I have yet to do the job, but here is my question: Are all gaskets created equal? If not, which brands should I buy and which should I avoid? Same question with spark plugs. Should I only buy an OEM gasket and plugs? Thanks in advance, I'm looking forward to turning the wrench on my car and avoiding ridiculous dealer prices.

Matt

 

Aftermarket parts are fine. Some parts like bolts and nuts are cheaper at the dealer than online, factoring in shipping.

 

 

 

I've had a single coil go bad on me before. If there is oil in the tube, then you are correct and should change the valve cover gasket pronto. Change the plugs and then drive for a while with the coils in the same order as before. If the misfires come back in #3 then you know the coil is bad. Order a new coil and that should solve it. No need to change all coils if only one is bad.

And I second aftermarket parts. You don't have to go OE all the time. As long as it is a decent brand OEM maker, bosch, mahle, etc. save your money.