BIGPOPPATAP

In my only other post I asked about oil in the spark plug tube, and was told to change the valve cover gaskets. I am waiting for them to arrive in the mail. The car is running kind of rough at times, though is still very drivable. I have a 75 mile commute, and not a lot of options while I wait for the parts. Am I going to destroy my engine if I drive it a few days this week?

Yes, it got a new timing belt at 95k. No other major work recently. Regular oil changes. Also, I had the transmission fluid flushed and changed a month ago. Also, I found out a might have made a major mistake. I switched from conventional oil to full synthetic and about 170k. My buddy said that that could actually cause a lot of damage. Is there any going back? Should I switch back to conventional?

Is there anything special I need to consider so as not to distort the tubes? Or just be super carefull?

I'm not doubting your expertise, I'm just curious. If it's the valve cover gasket why does only one of the spark plugs have oil on it? Are they sealed separately? I'll be changing this myself, probably the most complex mechanical fix I have ever tried, so I would like to figure out as much as I can before I try.

Thanks so much Fairtax4me. Would the Valve cover gasket cause the sputtering? Or is that the ignition coil? Or something else?

I have a 08 impreza 2.5i 188,000 miles. Lots of highway miles, I commute 150 miles a day. The check engine light came on yesterday, and the car started stuttering, mainly from accelerating from a stop, and sometimes when slowing down quickly. I stopped by O'riellys this morning and had the code tested. It read that cylinder 4 was misfiring. I Changed the spark plugs, hoping for an easy fix. Plug 4 was burnt on the tip. The cylinder next to it ( I don't remember which plug, the closest one to the front of the car on the driver side), had a plug that was covered in oil, though the plug was still in good shape. Afterwards the car ran well for a minute, though now it sputters and almost dies whenever I come to a stop. My buddy, a former full time mechanic (as in ten years ago), told me it was probably a blown head gasket. the online research I have done says it's a valve cover gasket, or the gasket at the end of the spark plug tube. Anyone have some good advice for a wanna be mechanic?