Rattle at 900rpm

[Tech By Trade]

I have a nice little rattle that comes up at around 900rpm, and is gone before the tac hits 1000 rpm. Its intermittent and seems to happen more when it is in drive but is still there in park. Its also more prevalent when cold. Sounds almost like a loose heat shield, and from the driver seat it seems to be on the passenger side and low. Any ideas?

 

[Tech By Trade]

delete

 

[Flag Gibby]

Have you checked for exhaust manifold leaks yet or maybe a couple of broken manifold bolts?

 

[calahan#2211]

definitely a frequency harmony thing. Most likely in the exhaust itself. How many miles on truck? I have just over 65,000 and have a catalytic converter beginning to rattle just off idle ( I do have cams and frequencies are a bit different/stronger, idles at 800rpm ). Also on the passenger side...

 

[Tech By Trade]

190k, cat sounds right.

 

[Tech By Trade]

She is a v6, I was almost thinking cat.

 

[motormaggot]

does it have the heat shield on the right side of trans pan? seen those get left loose and rattle against exhaust pipe.

 

[Tech By Trade]

It does, I did find a couple welds broken on the top of the heat shield on the passenger side pipe yesterday, but that still didn't stop it. Going to take a look at the heat shield tonight.
On a side note, the transmission was down a half a quart or so thanks to my leaky cooler lines I had last fall so I topped that off while I was under there.

On a side note, I'm not sure why the Mods figured they had to move my second post over from the 4th gen explorer fourm. This issue could be common to both as they share the same exhaust parts, and it would probably get more looks over there. Must have been a slow day.

 

[Tech By Trade]

Have you checked for exhaust manifold leaks yet or maybe a couple of broken manifold bolts?

well ****e, you were right. Drivers rear stud is missing. Looks like I have some room to manoeuvre but its still going to be a PITA. Not in a big rush, I will get to it when I get to it I guess.

 

[Tech By Trade]

I still don't think that's what I am hearing. It sounds like its coming from the other side of the engine. I may have to have a closer look this weekend when it is cold and I have some time.

 

[Tech By Trade]

its the y pipe/ dual cateletic converters. What a pain. Wonder if I can take it off and smash the core out. No inspections up here in the great white north.

 

[motormaggot]

you could probably get away with that, BUT, your check engine light will immediately illuminate with cat monitor codes. if emissions testing is not required, proceed at your own risk,

 

[Tech By Trade]

Think I will try the drywall screw trick when I get home tonight. Should hold for a bit. When that fails it looks like amazon has a walker y pipe for under 300 bucks including tax and shipping I may look into.

On a side note they were offering a $50 cash rebate so I bit. 2 new cats for 248 bucks shipped to the door ain't too bad.