Rattle / pinging noise coming from under middle of Jeep

garet f

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May 16, 2018
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San Mateo, CA, USA
Every morning when the jeep is about a quarter away from operating temperature. at the same time I turn on the same street there is a click/ spring bounce noise that comes from the exhaust. After this the exhaust sounds like there is a leak.. Not sure though.. as the exhaust will then rattle for the rest of the drive. it rattles specifically at this rpm.. however will continue to rattle throughout the rpm range
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Sounds like an exhaust leak .....likely just a donut gasket ....get it to an exhaust shop.....get gas first man, you are about empty!
 
on my jeep there is one cat and one muffler... Do you think I should cut the after the cat before the muffler. if it still makes the noise its the cat and if it doesn't it's the muffler?
 
In my humble opinion, an exhaust leak would not sound like a rattle. There are these heat shields around the cat and I would think that might be an area to look into. Try taking a good size screwdriver and slightly deforming the shield. in the past, I have found that those shields are notorious for making very nerve rattling noises. Good luck.
 
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Yes really all that I'm doing is taking a wild guess..... Really an exhaust leak would be more constant unless it somehow temperature dependent, which would be the case if you got to a certain point in your drive and then it starts acting up.

It's even possible that a catalytic converter is causing back pressure, but I loose heat shield or something is certainly possible.
 
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I will add that the post said the exhaust sounds like there is a leak... So somehow that is probably tied to it


I had one but it would only do it randomly and it was because the bolts up on the exhaust manifold were loose where the pipe comes together at the precats... And when you turned the pipe would shift.
 
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I will add that the post said the exhaust sounds like there is a leak... So somehow that is probably tied to it


I have one but it would only do it randomly and it was because the bolts up on the exhaust manifold were loose where the pipe comes together at the precats... And when you turned the pipe would shift.
 
That's how I found mine... I think I grabbed a hold of the exhaust to pull myself over on my creeper and the exhaust moved.
 
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Andy, If you know you have some loose bolts, the obvious thing to do when all is cold is to check and tighten all of them from the exhaust manifold back down to and including the fasteners at the tailpipe. After you do that fire it up and let it come up to operating temp. I hope this is on jack stands at this point. While wearing a real good pair of leather work gloves and a small piece of wood in your hand run it around the donut gasket between the exhaust manifold and exhaust pipe and all other joints and connections in the exhaust system. Don't know if you are aware of how much expansion occurs in that system from cold to operating temperature. But I will go back to my original statement that in almost all instances, a rattle is usually due to some sheet metal contacting something that it shouldn't be, and an exhaust leak will be singing a much different tune
Good luck brother,
Joel
 
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Andy, If you know you have some loose bolts, the obvious thing to do when all is cold is to check and tighten all of them from the exhaust manifold back down to and including the fasteners at the tailpipe. After you do that fire it up and let it come up to operating temp. I hope this is on jack stands at this point. While wearing a real good pair of leather work gloves and a small piece of wood in your hand run it around the donut gasket between the exhaust manifold and exhaust pipe and all other joints and connections in the exhaust system. Don't know if you are aware of how much expansion occurs in that system from cold to operating temperature. But I will go back to my original statement that in almost all instances, a rattle is usually due to some sheet metal contacting something that it shouldn't be, and an exhaust leak will be singing a much different tune
Good luck brother,
Joel
What is the piece of wood for?
 
Andy, If you know you have some loose bolts, the obvious thing to do when all is cold is to check and tighten all of them from the exhaust manifold back down to and including the fasteners at the tailpipe. After you do that fire it up and let it come up to operating temp. I hope this is on jack stands at this point. While wearing a real good pair of leather work gloves and a small piece of wood in your hand run it around the donut gasket between the exhaust manifold and exhaust pipe and all other joints and connections in the exhaust system. Don't know if you are aware of how much expansion occurs in that system from cold to operating temperature. But I will go back to my original statement that in almost all instances, a rattle is usually due to some sheet metal contacting something that it shouldn't be, and an exhaust leak will be singing a much different tune
Good luck brother,
Joel
Andy, you stated previously you thought you may have back pressure in the Cat converter. You never stated how many miles on your Jeep, but again in my very humble opinion, if you have a faulty cat which to your idea is causing back pressure, you would have much more serious problems than a rattle.Trust me.
 
Man has 30,000 miles and it didn't have a donut gasket... Mine has the flared fitting... Where the pipes collect and go down.

The entire downpipe was loose and I didn't have any idea. I think I drove it somewhere like eight or nine thousand miles that way.

It's all good and I added an additional hanger to the lower exhaust.... I think the previous owner must have eliminated one hanger when they did the lift.

And yes, buzz type rattle certainly sounds more like something getting hot and moving.

When people talk about noises on here most of the time we just thought start throwing out educated guesses.... I have found quite a few times when you're trying to chase something down it's not even what you think it is sometimes.
 
Man has 30,000 miles and it didn't have a donut gasket... Mine has the flared fitting... Where the pipes collect and go down.

The entire downpipe was loose and I didn't have any idea. I think I drove it somewhere like eight or nine thousand miles that way.

It's all good and I added an additional hanger to the lower exhaust.... I think the previous owner must have eliminated one hanger when they did the lift.

And yes, buzz type rattle certainly sounds more like something getting hot and moving.

When people talk about noises on here most of the time we just thought start throwing out educated guesses.... I have found quite a few times when you're trying to chase something down it's not even what you think it is sometimes.
 
Me too, especially on higher mileage vehicles.
 
Andy,
Basically you have a new vehicle. There is no such thing that there is no donut gasket between the exhaust manifold and the exhaust pipe. If you made that hard determination that this donut doesn't exist, I would like to know how you made this determination. Every vehicle has them up to and including my 2016 Silverado. I'm starting to wonder what exactly you are looking at. If there was no donut seal between these joints, there would be a helluva noise that most drivers would not tolerate. Andy ,what are you looking at?