pkn
Well-Known Member
- Joined
- May 16, 2011
- Messages
- 147
- Reaction score
- 4
- City, State
- Houston, TX
- Year, Model & Trim Level
- '92 '05 '10 2WDstockXLTs
Hi All,
Well, here it goes. Loud rattling sound from under the car, started overnight. I got under and looked - it comes from the left catalytic converter.
First I was hoping it's a piece of gravel or something, which got under the converter heat shield, but all my shaking, hitting, and careful listening with stethoscope convinced me that it rattles actually *inside* the converter.
And rattling does not change with vibrations change, only with change of RPM. Rattling occurs only at idle, all RPMs higher than 1000 quietens it completely. So it looks like the flow of exhaust gases moves the loose part around, causing rattle, but with higher RPM the exhaust flow pushes the loose piece in some corner and holds it there. Drop RPM below 1000 - and it rattles again.
Judging by the sound, it's a rather large piece of iron, maybe something similar 1/2" nut by size/weight.
The only hypothesis I could come up with is that the internal part of the front-left O2 sensor (it's located few inches above the converter) broke off and have fallen inside the converter. No, I did not yet read the codes to see if the sensor reports bad. But I know for sure (did emission inspection) that a week ago there were no codes.
So... so, my great plan is to unbolt the V-shaped part of the exhaust pipes (between the engine and the muffler) and shake out this little rattling jerk. Or fish it out with magnetic pickup, if I will be not able to take the whole V-pipe from under the car without too much of disassembling. And, of course, replace the broken O2 sensor if I'm right about it being broken.
Questions... heh, they've got to be rather stupid, but I gotta ask anyway. So, questions to the respected community:
Did anyone ever had similar problem? Or heard about it? )
Could there be another reason, different from broken O2 sensor?
Are all the three O2 sensors the same on 2005 Explorer XLT 6 Cylinders K 4.0L Flex Fuel SOHC?
Are there any underwater stones in unbolting the V-shaped exhaust pipe and taking it out of the car? I don't have a car lift, just jackstands.
Will the catalytic converter survive this mayhem, or I should replace it?
I have an inspection camera so I will probably be able to look inside the converter, but how do I judge if it's OK or badly damaged?
Many thanks in advance!
Well, here it goes. Loud rattling sound from under the car, started overnight. I got under and looked - it comes from the left catalytic converter.
First I was hoping it's a piece of gravel or something, which got under the converter heat shield, but all my shaking, hitting, and careful listening with stethoscope convinced me that it rattles actually *inside* the converter.
And rattling does not change with vibrations change, only with change of RPM. Rattling occurs only at idle, all RPMs higher than 1000 quietens it completely. So it looks like the flow of exhaust gases moves the loose part around, causing rattle, but with higher RPM the exhaust flow pushes the loose piece in some corner and holds it there. Drop RPM below 1000 - and it rattles again.
Judging by the sound, it's a rather large piece of iron, maybe something similar 1/2" nut by size/weight.
The only hypothesis I could come up with is that the internal part of the front-left O2 sensor (it's located few inches above the converter) broke off and have fallen inside the converter. No, I did not yet read the codes to see if the sensor reports bad. But I know for sure (did emission inspection) that a week ago there were no codes.
So... so, my great plan is to unbolt the V-shaped part of the exhaust pipes (between the engine and the muffler) and shake out this little rattling jerk. Or fish it out with magnetic pickup, if I will be not able to take the whole V-pipe from under the car without too much of disassembling. And, of course, replace the broken O2 sensor if I'm right about it being broken.
Questions... heh, they've got to be rather stupid, but I gotta ask anyway. So, questions to the respected community:
Did anyone ever had similar problem? Or heard about it? )
Could there be another reason, different from broken O2 sensor?
Are all the three O2 sensors the same on 2005 Explorer XLT 6 Cylinders K 4.0L Flex Fuel SOHC?
Are there any underwater stones in unbolting the V-shaped exhaust pipe and taking it out of the car? I don't have a car lift, just jackstands.
Will the catalytic converter survive this mayhem, or I should replace it?
I have an inspection camera so I will probably be able to look inside the converter, but how do I judge if it's OK or badly damaged?
Many thanks in advance!