ticking noise Gap closed in spark plug

If pistons are indeed meeting the plugs as you described.... Don't drive it anymore. W/O seeing or hearing it I would guess your bearings are letting go and therefore giving you a bit more travel on your pitons to allow them to touch the plugs under high rev's/accleration.

What kind of plugs are you running and at what gap? Does sounds like pistons are hitting the plugs.

Also maybe severe detonation down low, what kinda tune do you have on the car?

Did you replace the plugs? If so are the new ones damaged? I still stand that if there is noticable damage/marks on the pistons and the plugs have obviously been hit, you have some bad problems. Whether or not it still runs, I wouldn't drive it till you know for sure.

I find it hard to believe the pistons are saying hello to the ground straps.

I would use some modelers clay at the end of a plug, push it in there really well so that it won't come out and thread the plug in.

Spin the engine over by hand only, taking the rest of the plugs out will make things a lot easier.

Help needed in uk -sparkplug Gap closed - The Mustang Message Board

This cat has the same problem

Finally pulled the heads...


Did you ever upgrade your springs?

How many lbs of boost were you pushing?

Detonation could have caused the ring lands to start to break apart.

Hows your vacuum at idle?

My guess is detonation is most likely the culprit here.

I reviewed several cases and so far all applications have led back to detonation.

One was a NA case where the kid removed the EGR but never tuned it. The computer is set for the up to 10% inert gas and therefore would have led to detonation without a tune.

Two other boosted apps have complained of closed ground straps.

I borrowed this from NGK's site:

Detonation

The spark plug's worst enemy! (Besides fouling)
Can break insulators or break off ground electrodes
Pre-ignition most often leads to detonation
Plug tip temperatures can spike to over 3000°F during the combustion process (in a racing engine)
Most frequently caused by hot spots in the combustion chamber.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by mechanical action of the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (because of the force of the premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. The resulting shock wave causes an audible pinging sound. This is detonation.
Most of the damage than an engine sustains when "detonating" is from excessive heat
The spark plug is damaged by both the elevated temperatures and the accompanying shock wave, or concussion

If you can see damage to the piston tops, you now have stress risers which act as knife edges and will only lead to further detonation.

http://forums.stangnet.com/694778-piston-spark-plug-contact-any-ideas.html

This shows the NGK having an extended Tip… Check your NGK’s against Motorcraft

http://forums.stangnet.com/724198-spark-plug-pics.html

J smitty said:

ah.. thanks for the advice guys. how would I tell if its detonation? There is no pinging noise between 1000-2500 rpm a very consistant tick and revs up with the engine. It sounds like underneith the car. Could it be a piece of metal or something that could be in the engine and just be banging through the intake through these two cylinders? originally with the mongoose tune the spark plugs melted so a shop replaced them possibly not getting the tips out. yeah stock valve springs btw.

Click to expand...

Now that you have marks on the top of your pistons you have knife edges, which are known to cause pre-igntion---lighting of the fire before the spark plug does (like a glo plug). Detonation is two flame fronts colliding after the spark has arc'd usually due to low octane.

You either need to pull some timing out or run 100 octane and pray that the knife edges don't haunt you.

A tune is everything! You will want to put it on a dyno with a reputable tuner who will give you a conservative tune.