#2 cyl spark plug blew out!
 

ok guys, i need some help here. I mentioned below about having a ticking idle noise from my enigne compartment. Just got back from a ride and about 1 mile away from my house I hear this really strange noise. like a gridining noise coming from my enigne. power goes down quite a bit and the check engine light goes on. I pull over oepn the hood and the #2 cylininder spark plug is laying on my heat shield. I tightened it back in as best as I could, and drove home. The car has a bad vibration when accelerating from a stop. any ideas what could ahve caused it? perhaps when I changed the plugs back in spring this one was too loose? would the plug wires have to do anything with this? i kept the rpms below 3000 the rest of the way home. hopefully that prevented damage. If i just screw it back in good and tight and put the wire back on would it be ok to drive it? any help appreciated.
Mark

Mark:

That is strange. First, what year car and engine?

Are you saying the spark plug wire only or the spark plug wire with spark plug still in it?

You put the spark plug (and wire) back in by hand or with a tool?

What did the end of it look like? Meaning, the tip of the plug. Did you use anti-seize on the plugs? (don't)

If it was just the wire then you'd be running on 5 or 3 cylinders depending on your car and be dumping fuel into and through the cylinder. Not good for the engine and usually finds its way around the rings and into the crankcase (oil). Also, VERY bad for the catalytic converter as will make its way out the exhaust valve and straight to the converter.

I'd change the oil, check the other plugs for proper torque (in the Bentley manual), spray silicone or dialectic grease into the spark plug connectors and make sure you feel them click onto the end of the plug. I would use OEM Bosch plugs. NOT splitfire of platinum +4 tip or anything else. Many running problems have been partially cured by returning to OEM Bosch plugs.

Jason

my car is a 1990 325i. I have been having this problem, with the #2 cyl spark plug boot for sometime now. the spark plug just blew out today. It was very strange. I didnt have any of my real tools with me, so I just screwed it in as good as i can get it. Im gonna tighten it better tommorow and see if that changes anything. the strange part is the #2 cyl is the only plug and cyl with this problem. I changed the plugs, and it felt as iff it was stripped when I tightening it. also the #2 spark plug boot was coming loose. I think im gonna order new wires. this happened the first time. so im kinda nervous now to drive it.

It sounds like somebody cross threaded the plug at sometime and it has just gotten the threads so messed up that there is little or nothing left for the threads on the plug to grab onto. I would imagine that you are looking at (least) at having a helicoil installed in that #2 plug hole (if that will even work at this point).

In order for them to do that, they are (probably)going to have to pull the cylinder head but I think there are some places that can do this with the head still on the engine.

If you do a quick Google search on "Helicoil spark plug thread repair" you will find (I did) a bunch of articles on this that sound like a similar situation and companies that supply the tool (which you should be able to find at Napa).

Rich