Engine noise but no codes!

[denalianyone]

Has this engine noise for about 2 months now. The rpm fluctuates while idling from 600 to 800 RPM's. Sometimes it will even stay at 800 while parked or at a stop light. Truck runs great otherwise. I'm attaching two links with the sounds, one while idling and the next while revving.

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[Captynrj]

Got that same rattle on mine

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[08grey]

First one sounds just like mine. Second one sounds like your cats might be breaking down and rattling inside.

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[denalianyone]

Yea it's hard to diagnose especially with no codes. I have about 86k on it. My local mechanic said that my flywheel might be cracked. I would hate to separate the tranny n such, to find out the issue is something else.


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[iamdub]

Yea it's hard to diagnose especially with no codes. I have about 86k on it. My local mechanic said that my flywheel might be cracked. I would hate to separate the tranny n such, to find out the issue is something else.


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Pop out the inspection plug and grab a bright flashlight to look at the flexplate. I don't recall, but I think there's a coupling right after the cat that you can unbolt and move the pipe out o the way to look inside the cat.

 

[denalianyone]

Pop out the inspection plug and grab a bright flashlight to look at the flexplate. I don't recall, but I think there's a coupling right after the cat that you can unbolt and move the pipe out o the way to look inside the cat.

Inspection plug?? Not the o2 sensor


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[iamdub]

Inspection plug?? Not the o2 sensor


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I was talking about checking both aforementioned possibilities. To check for a cracked flexplate without removing the trans, you can pop out the inspection plug and look inside with a flashlight. It's a round metal plate that can be popped out with a small flathead screwdriver that'll give you a about a 2" hole to look through. Sure, you won't have as clear a view as with the trans removed, but at least it's a quick and easy check that'll allow you to (hopefully) eliminate it from the list. The second part was for visually checking for a clogged cat. But, I completely forgot that these things have two cats, one on each bank of the Y-pipe. About the best you can do with that for an at-home test is comparing the temperatures of the exhaust pipe entering and exiting the cat converters.

 

[Ciro]

I have seen that inspection cover while changing my oil, Is this one on the image?

 

[iamdub]

^^^ That's it.

You can see the teeth on the flexplate in the second pic. You'll have to look through the hole and between the flexplate and the torque converter that's bolted to it. But, spend a few minutes looking at it with the flashlight at various angles. If you see anything suspect and/or need to rotate the flexplate for a better view, you can turn the motor with a large ratchet and socket on the crank.

 

[nathanhanover]

The Rattle is probably your Catylitic converter. I bought a new one. and it rattled right out of the box had to have a new one sent.
The other noise I can't even distinguish. But if your idle varies it's probably the Trottle posion sensor, about 50 bucks at O rielly