ticking noise Gap closed in spark plug

J smitty

New Member
Mar 22, 2007
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Foristell Mo
so my 04 t- trim gt has this slight ticking noise at slight acceleration (before 2500 rpm) then it goes away. I jacked up the car the noise seems to be coming from behind the front wheels by like the transmission or where the midpipe connects to the stock manifolds. Also any time I drive the car the spark plug gap closes along with a grinding noise. But every time this happens its a different plug? Used bore scope and looked at pistons they all look good but like two of them are showing slights dents. I used a modified vaccume to suck out the cylinders. What could be the problem? The car has 35000 miles on it 1000 with the t trim. changed the oil no metal pieces when ran through a stocking. I don't know what the deal is.
 
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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.
 
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
 
Ya I put new plugs in. the car closed the one gap passenger front closest to the grill. I put all new plugs in it. then I took it out (same ticking noise) car drives "normal" and sounds good but at WOT I heard a grinding noise so took it back and then driver side back plug closed gap. those are the two pistons with the damage too. now it happened again havent remoed the plugs yet but Im sure the same thing happened. Idn the detonation thing is pissing me off tho. I had the mongoose tune originally, then custom dyno tune. Its a ****ing mustang there are billions how come they cant make a kit that ****ing works.:notnice:
 
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.
 
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.

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.
 
Yeah I agree with you. I went to FORD today and he said judging by what I said its pre-detonation. But how i relocated the IAT sensor after the blower shouldn't it be taking timing out if its unsafe? He said to buy at least forged pistons and rods. I would rather buy this shortblock Products » Shortblocks » MMR » MMR 4.6 Street Mod 900 Or if there is a better one? He also said to get subframe connectors, intercooler and boost and wideband gauges. But the tune is still gonna be off so what should I do?