rattle sound after gas (1997 XLT 4 door SOHC V6)

[Lazerskull]

so my 1997 XLT SOHC V6 runs fine. it has no major issues. it has a new radiator. new transfer case. new timing tensioners. new belts. been running synthetic for the past 100K. great truck!

recently, after I give it some gas, it does this little rattle sound. power seems to be fine, has plenty of torque.

underneath the rig I found some tranny oil on the bottom of the pan. so could be a leaky gasket there.

is the noise from the catalytic converter or is it stuff rattling in the tranny pan?

reply to this message for my email and I can send you a video.

 

[GLOCKer]

Maybe fill it with higher octane gas for a couple tanks and see if it goes away?

 

[Lazerskull]

I heard high octane can mess with a transmission...

Anyway. I went down there and banged around. Slapped my hand on the muffler. Sure enough made the sound.

So the muffler is loose, no big deal.

And the transmission oil has been leaking all over the place, I guess the bolts just get loose over time.

Maybe I'll upgrade the muffler someday, until then I'll just live with the sound.

 

[Mbrooks420]

I can’t see how higher octane would mess with a transmission.......

 

[GLOCKer]

I heard high octane can mess with a transmission...

Anyway. I went down there and banged around. Slapped my hand on the muffler. Sure enough made the sound.

So the muffler is loose, no big deal.

And the transmission oil has been leaking all over the place, I guess the bolts just get loose over time.

Maybe I'll upgrade the muffler someday, until then I'll just live with the sound.

Running higher octane fuel wont do anything to your transmission. If I remember correctly, lower octane fuel can cause detonation and pre-ignition conditions in those 4.0 motors and can result in a rattling noise on throttle. Typically running a few tanks of high octane through clears up that resulting rattling noise if the fuel is the issue.

If I were you I'd consider running a couple of tanks of high octane fuel through even though you you believe it's the exhaust. Also check your plugs? If the rattling noise is happening on throttle and not all the time, you may have detonation/pre-ignition issues that can lead to severe engine problems down the line. Spending a little more on fuel may keep that from happening.

 

[GroupExploder]

Cat converter inerds coming apart? cam chains making noise?

 

[donalds]

Running higher octane fuel wont do anything to your transmission. If I remember correctly, lower octane fuel can cause detonation and pre-ignition conditions in those 4.0 motors and can result in a rattling noise on throttle. Typically running a few tanks of high octane through clears up that resulting rattling noise if the fuel is the issue.

If I were you I'd consider running a couple of tanks of high octane fuel through even though you you believe it's the exhaust. Also check your plugs? If the rattling noise is happening on throttle and not all the time, you may have detonation/pre-ignition issues that can lead to severe engine problems down the line. Spending a little more on fuel may keep that from happening.

You all may jump my Ass for this but I
Have seen this problem on my friends 98 sport
He had a tank full of gas at about 1500 rpm
It sounded like rocks in a blender
Predetonation
Spark knock
EtceteRa

I heard my grand pa in my head
He was a big believer in marvel mystery oil
So I put a half of a bottle ..no you can't hurt it with any amount of mmo I have even added a whole bottle ...
It stopped in 2 min drive look at the bottle be for yelling at me easy way to tell if that's the problem

If I am wrong correct me
But it did work

 

[GroupExploder]

marvel mystery oil works
use it in everything

 

[Mbrooks420]

Sounds like he just had carbon build up.