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Discussion Starter #1
During the cold start, I hear knocking in the engine for just a few minutes until the car has warmed up and I was just wondering if this is something to be concerned about or not? Thank you.
 

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Yeah, it would concern me. It could be a number of things. It should be diagnosed ASAP to avoid irreparable damage if something serious is afoot.
 
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Yeah, it would concern me. It could be a number of things. It should be diagnosed ASAP to avoid irreparable damage if something serious is afoot.
What he said. Bad cam phasers would be my no.1 suspect. Use a mechanic's stethoscope to localise the noise and help you diagnose it.
 

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A few minutes? I would start with inspecting the timing chains / guides or cam phasers.
Yes it goes away as soon as the car has warmed up.

What he said. Bad cam phasers would be my no.1 suspect. Use a mechanic's stethoscope to localise the noise and help you diagnose it.
Should I take it to Ford or to a mechanic instead? i am new to the mustang Gt's so I have no idea how much should it cost to be checked or replaced and don't want to be ripped out either. any advice on costs and what to ask them to check specifically?

Yeah, it would concern me. It could be a number of things. It should be diagnosed ASAP to avoid irreparable damage if something serious is afoot.
I searched around online and it seems to be piston slap as they said if it goes when it is warm then its just a piston slap and it is normal. Im not sure honestly
 

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I searched around online and it seems to be piston slap as they said if it goes when it is warm then its just a piston slap and it is normal. Im not sure honestly
That’s one possibility for sure, but if I were in your shoes, I’d have a trusted shop diagnose the noise. It’s not free, but it’s worth it.
 
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That’s one possibility for sure, but if I were in your shoes, I’d have a trusted shop diagnose the noise. It’s not free, but it’s worth it.
How would such a diagnosis be conducted? Without tearing engine apart?

Piston slap immediately comes to mind, especially if the noise goes away completely and fairly quickly. Excessive clearance in a bearing, either rod or main, will INCREASE in intensity as the engine warms up, and oil gets thinner. Piston slap, on the other hand, DECREASES as the piston gets hot and expands. Also, lubrication to the cylinder and piston is minimal for the first few seconds of engine running; oil reduces piston slap, as does heat. However, piston slap lasting for MINUTES indicates excessive piston clearance, possibly a cracked piston.
 

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I’m just saying that a good shop, doing some level of diagnoses (even if all they have is a very experienced mechanic with a rubber hose) is better than an internet guess. IMHO
 

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How would such a diagnosis be conducted? Without tearing engine apart?

Piston slap immediately comes to mind, especially if the noise goes away completely and fairly quickly. Excessive clearance in a bearing, either rod or main, will INCREASE in intensity as the engine warms up, and oil gets thinner. Piston slap, on the other hand, DECREASES as the piston gets hot and expands. Also, lubrication to the cylinder and piston is minimal for the first few seconds of engine running; oil reduces piston slap, as does heat. However, piston slap lasting for MINUTES indicates excessive piston clearance, possibly a cracked piston.
Yes, it goes away after the car is warm it doesn't last longer than 5 minutes depending on how the weather is but I will keep checking. How long should it be for it to indicate a cracked piston?
 

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Yes, it goes away after the car is warm it doesn't last longer than 5 minutes depending on how the weather is but I will keep checking. How long should it be for it to indicate a cracked piston?
Piston noise emanating from a crack in it's structure will likely not go away. A cracked piston would likely also have damaged/cracked rings.
 

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Piston noise emanating from a crack in it's structure will likely not go away. A cracked piston would likely also have damaged/cracked rings.
I appreciate it, you guys really educate me a lot since I've joined this community.
 

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Hands
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A mechanic's stethoscope, a pair of ears, and a human brain are amazing tools that work incredibly well together when used. ;) :D
One can often save the time and cost of tearing apart an engine or driveline assembly by carefully listening and looking for simpler problems, just as you say!
 
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