1998 Mustang Gt Strange Knocking Noise. only 104,421 miles! - Ford Mustang Forum
 
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post #1 of 8 (permalink) Old 02-15-2007 Thread Starter
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Exclamation 1998 Mustang Gt Strange Knocking Noise. only 104,421 miles!

I hear a strange knocking noise, especially when I start it cold. Before I heard this noise, I do admit, I would run it pretty hard. I change my oil every 3,000 miles with Castrol Syn and I keep up to date with all my fluid exchanges, air filter etc... When I have it at Idle, I rev it between 1300 and 1500 rpm and the engine and steering wheel vibrate pretty hard, when I pass 1500 it idles smooth. The knocking noise seems to be coming from the bottom of the engine. I also have a rear main seal leak..can anyone tell me what the sound may actually be? And am I better off selling it? or actually fixing these problems. I should also add that I changed my oil on Jan 2nd, and when I removed the oil plug, I saw metal shavings. Any help will be greatly appreciated, thank you for your time.
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post #2 of 8 (permalink) Old 02-16-2007
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welcome to AFM!

sounds like a connecting rod at the crank.

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post #3 of 8 (permalink) Old 02-16-2007
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Welcome... Tough to diagnose fully without taking it in. Sounds like you've definitely got a serious problem.

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post #4 of 8 (permalink) Old 02-16-2007
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this is an easy one... you have spun a rod bearing. Very typical of 4.6L engines.
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post #5 of 8 (permalink) Old 02-16-2007
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Quote:
Originally Posted by Slipintobliss View Post
I hear a strange knocking noise, especially when I start it cold. Before I heard this noise, I do admit, I would run it pretty hard. I change my oil every 3,000 miles with Castrol Syn and I keep up to date with all my fluid exchanges, air filter etc... When I have it at Idle, I rev it between 1300 and 1500 rpm and the engine and steering wheel vibrate pretty hard, when I pass 1500 it idles smooth. The knocking noise seems to be coming from the bottom of the engine. I also have a rear main seal leak..can anyone tell me what the sound may actually be? And am I better off selling it? or actually fixing these problems. I should also add that I changed my oil on Jan 2nd, and when I removed the oil plug, I saw metal shavings. Any help will be greatly appreciated, thank you for your time.


Yup most likely your crank is warped or a rod bearing is bad.........I just got thru rebuilding cause of this.....the more you drive the worse it wil get and then eventually ruin your whole engine......My cause was low oil and degrading parts.
Good luck

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post #6 of 8 (permalink) Old 02-18-2007
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Ouch. Sounds like engine knock of doom. I have had 3 engines do it so far. The new one wont do it hopefully cuz i have like 8 g's into it and its not done. When My original 1998 engine did it, it was like a clicking that sounded like it was coming from under the intake manifold, and it would appear and disapear with differing rpm.

Ur most likely gonna have to tear into it man.

Good luck,
Andy
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post #7 of 8 (permalink) Old 02-18-2007
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Yea metal in the oil is not a good sign. It's most likely a spun bearing. You need to drop the pan and look at the rods/bearings. DO NOT drive/run the car any more. At this point you need to consider an engine rebuild. Or you can buy a new engine. Just depends on how much $ you have.

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post #8 of 8 (permalink) Old 02-18-2007
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My car when I threw a rod bearing, when the car was first started it wouldn't really make any noise it was when the oil warmed up it would start knocking. If you just get a engine that comes out of a wrecked car then you really dont know how it was treated or anything. I would build it with new forged rods and pistons. It should last you a long time then.

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