Rattling noise only in drive with brake on

[sullami]

Hi guys I tried to search for this but seems tough to get the keywords right.

I have a 98 ohv 4.0 and just noticed today when I am in drive and stopped there is a strange rattling noise like a rock our something rapidly bouncing around in a can. When I am in park or any other gear there is no noise also seems to amplify if I turn the wheel slightly, also while not moving.

Any Ideas?
Thanks

Apparently in reverse now too there is a delay when shifting from drive to reverse

 

[italianbigsky]

This is my experience:

I heard the noise louder in D with brakes on, and seemed to disappear in N or P.

In 1,2 or R I could hear it with brakes on.

While driving, it's hard to know because there are too many noises around.

Anyway, the result was the flexplate damaged, it crashed right in the middle.

maybe, stopping the car as soon as possible would have saved my torque converter. I kept on driving, the noise went louder and louder each passing miles, untile I noticed the fluid leaking under the converter.

Check the flexplate, maybe I'm wrong but I still have to pay repairs.

 

[Abbondanza]

Had the exact same symptoms, most likely the tensioner belt pulley bearings are shot, replace the whole unit (20 min job) and while the belt is off, change the idler pulley also.

The delay in reverse is a different issue, related to transmission age, maybe an AT fluid and filter change may help.

 

[RomeovilleIL]

Have someone stand outside the truck and listen to see if they can isolate to one area.

On both my ex's I started getting a metallic rattling sound while in gear at a stop that turned out to be the heat shields and an exhaust hanger. The heat shields looked normal but had broken welds on one side so it could move maybe 1/4". Thought I had the worse case of timing belt noise ever except it disappeared the moment you gave a little throttle. The broken hanger was against the frame causing some significant irregular vibration and metallic rattle. So... as always, you need to do some investigating before you will get an answer. There are a lot of possibilities.

 

[ahodges]

probably a heat sheild

 

[SoNic67]

I had that with worn-out motor mounts. The whole engine was moving due to counter-torque (torque converter against brakes) and exhaust manifold was touching the heat shield at idle in D.
Noise intesifies when you turn wheels because the increased counter-torque generated by steering pump (under load).
While driving, the counter-torque is usually less (unless gunning it).
Have somebody look at engine while switching from D to N.

 

[sullami]

Indeed, it ended up being a small heat shield on a piece of exhaust pipe under the front passenger the cheap clamp thing was pooched. Secured it with some rebar/tie wire at work and voila!
Thanks

 

[drdoom]

Indeed, it ended up being a small heat shield on a piece of exhaust pipe under the front passenger the cheap clamp thing was pooched. Secured it with some rebar/tie wire at work and voila!
Thanks

lol got some of that under my truck too!