tualatin

Hi everyone, I'm having weird problem with spark plugs. First time I was having problem on a highway about a month ago, my engine started shaking like on of the cylinders stopped working. After coming home I decided to change spark plugs and noticed that there were a lot of oil in spark plug wells. I haven't time to change valve cover gaskets and decided to clean it up and change them later. During changing plugs I saw that last spark plug's terminals joined for some reason!!! About a week ago I have experiencing same troubles with misfiring engine. I bought valve cover gaskets. Cleaned everything, changed gaskets. Then I was checking spark plugs... And one of them (not the same!!!) was joining terminals again like a month ago... It was new spark plugs.
What is happening with spark plugs???

Dirtybrd

Something is hitting the electrode. Sounds like you might have an extreme amount of carbon built up, Do you ever hear any odd noises when its running? Did you replace the plugs with the correct plugs, ones to long could hit the piston, but they seem the correct length in the thread area

jcat_350

First, let's clarify terms so we're not giving bad info. The part that's bent back in that picture is the ground strap. The electrode is the little nub that the ground strap is bent back into. The terminal is the little end cap that you place the spark plug wires/coil connectors on.

If your pistons were hitting your plugs, it would break the ground strap off. The typical cause of this issue is detonation. Are you noticing a misfire when good plugs are in the car? What grade gasoline are you using? When's the last time you serviced the engine? Is it throwing any codes?

Typically detonation is caused by bad gas, a failing knock sensor, or a combination of those. Get the ECU scanned for codes and let us know what you come up with.

tualatin

Thanks for replies. My ECU does have only error code about oxygen sensor. Grade of gasoline is some kind of 92. I'm using it since I bought this car three years ago. I don't know what is equivalent grade of gasoline in USA. Misfire begins only when terminal is bending. It works well before this. I've been searching on web and found similar symptoms... but the reason was broken shutter or valve pieces in air connection tube after throttle body that were hitting spark plugs inside cylinder... Have to find out it someway.
I'm waiting the third time my spark plugs will be injured.