[Evo_Geo]

Hey all,

I've been hearing this rattle, and the topic finder helped me find a thread that describes the rattle and identified it as possible shattered catalytic converter or broken flex pipe.

So I crawled under and started thumping the heal of my hand on different parts of the exhaust. There is definitely a rattle when I thump the pipe between the flex pipe and the cat.

So here's the question: Do I need to replace this part? The noise drives me nuts, but if I turn on the radio (even at a reasonable volume) I can't hear it. If it won't hurt it to leave it alone, I'd rather wait a bit. I'm a student and funds are low. At the same time, the opportunity to take a wrench to the car is tempting.

Also, am I correct in assuming that I can remove the flex pipe and cat where they attach to the y pipe and resonator to just replace this section of the exhaust?

edit: sorry. Its a 2002 Taurus SES 3.0L V6 OHV 103K mi.

Thanks,
Geo

 

[sheila]

Its not a loose heat shield above the cat is it?

 

[Evo_Geo]

Thanks for the reply.

I'm going to say no to the loose heat shield because the noise is much more prominent when I knock on the pipe leading into the cat or on the flex pipe itself.

Geo

 

[Evo_Geo]

Some more clarification:

It doesn't sound like a marble rolling around in there like I see in some you tube videos I just looked at. It sounds more like what ever it is is attached to the inside and repeatedly taps against the inside as it shakes after I knock on it.

While the engine is running, and while in the driver seat, it sounds like metal scraping on pavement, but with weight on it, not like a bouncing muffler. More like if i rode a metal garbage can lid down a steep road (that brings back memories), but not that loud.

It is not present while idling, is loudest with high rpm, and can be produced with the car in park (in cold weather it can be heard on high idle immediately after startup).

This seems to describe the flex pipe issue I found with the topic finder.

 

[sheila]

That was my next thought, a cat breaking up internally. If you cant find the source shaking and tapping underneath, might try a local mom and pop muffler shop to investigate. Theyre usually pretty reasonable moneywise. Maybe have them diagnose and fix depending on the cost, or you do the repair if able.

 

[JW657]

That was my next thought, a cat breaking up internally. If you cant find the source shaking and tapping underneath, might try a local mom and pop muffler shop to investigate. Theyre usually pretty reasonable moneywise. Maybe have them diagnose and fix depending on the cost, or you do the repair if able.

If there's one thing I hate doing it's exhaust work. I try to source all of that to my local garages.

 

[sheila]

^+1!!!

 

[Evo_Geo]

I replaced the exhaust (everything past the cat) on a mid 90's windstar in high school. I'm not scared B).

 

[the_intimidator_02]

Check the mesh on the flex pipe. Mine had a metal ring that rotted around it and would rattle.

 

[jsixis]

my 93's cat shield makes all kinds of racket when I first apply the gas.
Just tapping on it with my fingers makes the same noise only quieter.
It sucks but I'll live with it for now.

 

[Evo_Geo]

Maybe i'll just crash this mother into a tree :angry:

I just had the cam sensor replaced and everything was peachy other than this rattle. Now the engine acts like its running out of gas when I put it in drive or reverse. If I try to give it a little extra gas on the highway to pass someone it does the same thing. Could this exhaust rattle be the cause or am I dealing with a bigger problem maybe?

I suppose it could be the cam sensor, but I took it back to the dealer twice because they misaligned it and the check engine light came on. They checked it on an oscilloscope to get it right the last time, so I'm thinking that's not it.

Geo

 

[KhanTyranitar]

It is possible that if the rattle is a broken converter, that it may be plugged and restricted, and that will definitely cause a power loss. But you need to do some tests to confirm this is the case. Try unbolting the converter from the rest of the system and see if that doesn't fix the problem (warning this will be loud). If the power has dramatically improved, the the rear converter may be plugged. If it made little difference, a whole host of other sources may be the cause.

 

[Evo_Geo]

Thanks for the suggestion Khan. I'll have to find some time this weekend to crawl under there.

Couple questions. Can I just unbolt the cat at the y pipe and let it hang (just to test this i mean) or do i need to remove it altogether?

Also, I seem to remember this happening this time last year, as the weather got colder. Last Feb (I think), the car turned off completely for a moment (maybe 1 full second) while traveling at 40 mph. It was early in the morning and I had headlights and radio on too. Everything, including the engine turned off. I think being in gear and the movement started it up again, like popping the clutch with a manual trans.

All summer the car runs great. Then in the fall this rattle starts (last year too), and the engine wants to turn off. Is this indicative of a particular problem?

Geoff