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exhaust leak or engine knock

Old 04-10-2007, 04:03 PM
  #1  
JimboGT01
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Default exhaust leak or engine knock

I have mac long tubes and two days ago i started to hear a little knock sound and at first i thought it was something hitting on something metal because it had that kind of sound but now i have started to wonder if it is a exhaust leak. It doesnt do it right away when i start the car in the morning but the rest of the day i have this horrible ticking noise. It happens wether the clucth is engaged or not and it speeds up with the rpms. My girlfriend said that it gets really loud when i get on the gas. ( i had her listen as i drove away from her house last night) What do yall think it is? is there a easy test to check whether it is a exhaust leak or not? And what problem in the engine could make this noise: spun bearing, thrown rod....anything?
Thanks
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Old 04-10-2007, 04:45 PM
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2002GTAUTOVERT
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Default RE: exhaust leak or engine knock

sounds like an exhaust leak, make sure your bolts are torqued to specs. and did you replace any of the gaskets
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Old 04-10-2007, 05:38 PM
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xander0561
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Default RE: exhaust leak or engine knock

yea man totally an exhaust leak. I had the same thing happen to me. If it were a knock you would know. Check the pessenger side, for some reason mine was always on that side, I dont know if its just a characteristic of the beast or if its just my car.

its not a thrown rod, the engine wouldn't idle, it probably wouldn't even run. I guess it could be a spun bearing, but when that happens its more of a rap than a tick.

given that you just put the exhaust on they are going to expand and contract with the heat, until that are broke in. So I'd give it a 90% chance that its a leak.
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Old 04-10-2007, 06:04 PM
  #4  
PWORLDSTANG
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Default RE: exhaust leak or engine knock

^^ +1 on what they said. I have an exhaust leak. It sounds a lot like a car pinging.

Knock sounds different. Knock sounds literally like metal knocking hard against something else that's metal. It's a horrible sound.

Fortunately for you, and exhaust leak can be fixed. They are somewhat common with long tubes though. And sometimes they do come back after you fix it. But just make sure you replace the gasket and retighten everything.
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Old 04-12-2007, 09:14 PM
  #5  
JimboGT01
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Default RE: exhaust leak or engine knock

well i got under the car today and tighted everything down but the sound is still there. When i was under it the sound seemed like it was coming from the engine. Could it be one of my cylinder detenating.
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Old 04-12-2007, 09:19 PM
  #6  
rbstang
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Default RE: exhaust leak or engine knock

ORIGINAL: PWORLDSTANG

^^ +1 on what they said. I have an exhaust leak. It sounds a lot like a car pinging.

Knock sounds different. Knock sounds literally like metal knocking hard against something else that's metal. It's a horrible sound.

Fortunately for you, and exhaust leak can be fixed. They are somewhat common with long tubes though. And sometimes they do come back after you fix it. But just make sure you replace the gasket and retighten everything.
pinging doesnt really sound like an exhaust leak.... if your car sounds like its pinging.. you might be running way to lean and i would have that checked out... my car was pinging on the dyno and then later i had an exhaust leak the 2 sounded nothing a like....
and exhaust leak sounds like paper flapping in the wind.. pinging.. i cant really explain what that sounds like...
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Old 04-12-2007, 09:20 PM
  #7  
JimboGT01
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Default RE: exhaust leak or engine knock

is running lean= to much timing
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Old 04-12-2007, 09:23 PM
  #8  
rbstang
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Default RE: exhaust leak or engine knock

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is running lean= to much timing
yes. if you have like a hypertech tuner or a superchip micro max tuner, or any of those other cheap a$$ tuners.. more then likely your running lean if the tune is installed. if you have an sct tune or diablo tune you should be fine... it usually only happens with the cheapo tuners. because they advance the timing so much its absolutely ridiculuos. Thats why my car was pinging on the dyno. cuz of that crappy hypertech tune.
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Old 04-12-2007, 09:34 PM
  #9  
lizzyfan
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Default RE: exhaust leak or engine knock

ORIGINAL: rbstang

pinging.. i cant really explain what that sounds like...
like marbles in a tin can
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Old 04-12-2007, 09:37 PM
  #10  
JimboGT01
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thats exactly what it sounds like.......a ball bearing bouncing around in my engine
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