How to spot exhaust leak?

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  #1  
Old 03-03-13, 04:33 PM
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How to spot exhaust leak?

Hey all

Wife's RX300 developed exhaust noise somewhere in the front of the engine bay. It's transverse V6. We can even smell exhaust standing there, with hood open. Sound is typical - fffffrrrrrrrrrrrrrrrrr. Or, you can consider very fast put-put-put...

So far, I failed to find what exactly is leaking it, though I tend to think it's the donut shaped seal between bank one exhaust manifold and cat.

No signs of soot, dark streaks, or such. No hot air blowing against hand, as far as we could reach there.

Anyone knows how to spot such a leak?
 
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  #2  
Old 03-03-13, 05:24 PM
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Stethoscope with a probe end.
 
  #3  
Old 03-03-13, 05:26 PM
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Tried that. Did not help.
 
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Old 03-03-13, 08:02 PM
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the best way i know is to plug the tail pipe with rags or something like that. it will increase the flow out the leaking area making it more noticeable. the most typical area for these to leak is the flex pipe.
 
  #5  
Old 03-04-13, 05:09 AM
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Ukrbyk,

Iceman691 is right and I agree with him. Watch this video.

How to Find Exhaust Leaks - EricTheCarGuy - YouTube

Thank You
Amy
 
  #6  
Old 03-04-13, 12:36 PM
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Likely a braided flex section in the exhaust system. I bet that's the fault.
 
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Old 03-04-13, 01:53 PM
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Ukrbyk,

In all honesty the mentioned braided section of the exhaust system is really the strongest part of the system. Without a doubt the leak will be after the braided section of the exhaust. Just post back if you have more questions (and or issues) that I can help you with.


Thank You
Amy
 
  #8  
Old 03-04-13, 03:25 PM
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My 87 Taurus had cracks in manifold and I could spot it by flames flying out through them in the dark.
I'll find out next week, I am on vacation and that frrrrrrrrrr really gets on my last. I bet it's the donut seal between manifold and cat downpipe.

Thanks all for suggestion.
 
  #9  
Old 03-04-13, 06:49 PM
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Ukrbyk,

Iceman691 is right and I agree with him. Watch this video.

How to Find Exhaust Leaks - EricTheCarGuy - YouTube

Thank You
Amy

Read more: http://www.doityourself.com/forum/pa...#ixzz2Md749yK9


I like Eric. He's my kind of guy. I'll try it. Next week - here I come!
 
  #10  
Old 03-05-13, 06:59 AM
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Squirt something in the intake to make the engine smoke,then look for the smoke signals. No guessing, no burned fingers.
 
  #11  
Old 03-05-13, 08:25 AM
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Will marijuana work, considering it's legal in the state now?
 
  #12  
Old 03-06-13, 06:46 AM
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Ukrbyk,

A smoke machine and a bright light is another method, but a good smoke machine is expensive. First thing is to use a lift to find the leak. You'll have better luck that way than on your back. Another method I've used, is to have a friend put on a welders glove and cover the exhaust with his hand. Now I walk the length of the exhaust system (very slow) with a candle. When the flame from the candle finds the leak, the flame will move and blow out. At that point you found your leak.

Thank You
Amy
 
  #13  
Old 03-06-13, 01:19 PM
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I like the candle thing too. I'll smoke some marijuana, get under, and walk with candle underneath. I think, it's going to make a fantastic youtube peace. Maybe a black silk hooded robe....

Thanks, Amy. It's all good, viable suggestion. I am just in very good mood today.
 
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Old 03-06-13, 01:24 PM
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Run it fairly low on gas and throw a can of Sea Foam in the tank, that'll smoke.
 
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Old 03-06-13, 01:28 PM
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Oh yeah, I know THAT!!! Add it to combustion chambers. Done few times. It's like military smoke generator.
 
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Old 03-06-13, 01:41 PM
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I've smoked out the whole neighborhood adding it directly.

Good times
 
  #17  
Old 03-10-13, 04:36 PM
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Surprise. G'ol soap water works just fine. I made it real soupy.
It leaks right through the front upstream cat gasket, where it's connected to the flex pipe, id est - the bottom junction with exhaust pipe. Fortunately, entire cat is 2 and 2 bolts to undo and pull, nothing major. Looks like I can simply undo bottom 2, and pull that gasket out and replace. 4 bucks. If it fixes it, amen, if not, it's $180 Magnaflow cat.
 
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