grinding noise from engine on '99 Jimmy

[ggsz28]

New member here hoping for some help with my truck. I've got a '99 Jimmy SLT 4WD w/ 102K miles and I've owned it for the past 30K. Whenever I am stopped at a light or stopsign and I take off with anything more than light throttle then there is a horrible grinding sound from under the car/forward part of the car. The grinding lasts for about 1 - 2 seconds. It doesn't do it when I use light throttle but it does every single time when I use say 50% throttle or more. It doesn't matter if the engine is hot or cold. This is the only time it grinds...never at any other speeds. I have some experience with cars but none w/ 4WD. Can someone please tell me what's going on here?
Thanks,
Geoff

[rcraig77]

I have the same problem with my jimmy, also 1999, wondering if you have heard anything?

[leeder70]

is the 99 jimmy's a belt driven coolant fan????
if so i would be looking into a motor mount being alittle weak or even broke causing the fan to get into the shroud. when you throttle hard it lets the motor tilt.
not sure but worth a look
let me know

[BlazerLT]

Sounds like a rattling cat convertor.

This is what mine was doing. Go under your truck and whack the cat with the palm of your hand and listen for any rattling.

[ginger444]

I have a tube running from my rear axle onto the frame. Looks like a filler tube. How do I access and how do I tell how much oil may be needed?

Cheers

[drdd]

put the truck in park and rev to 50% throttle. Do you hear the sound? This may help you determine whether the sound is associated with the engine rotation or the wheel rotation/suspension.

ever greased your front end? there are 11 zirc fittings to grease. Too easy not to do.

ever changed your transfer case fluid. If not, do it, its easy and if it doesn't solve your problem, you haven't wasted any money cuz its preventative maintenance anyways.

Originally Posted by ggsz28

New member here hoping for some help with my truck. I've got a '99 Jimmy SLT 4WD w/ 102K miles and I've owned it for the past 30K. Whenever I am stopped at a light or stopsign and I take off with anything more than light throttle then there is a horrible grinding sound from under the car/forward part of the car. The grinding lasts for about 1 - 2 seconds. It doesn't do it when I use light throttle but it does every single time when I use say 50% throttle or more. It doesn't matter if the engine is hot or cold. This is the only time it grinds...never at any other speeds. I have some experience with cars but none w/ 4WD. Can someone please tell me what's going on here?
Thanks,
Geoff

[BlazerLT]

Originally Posted by ginger444

I have a tube running from my rear axle onto the frame. Looks like a filler tube. How do I access and how do I tell how much oil may be needed?

Cheers

Can you take a picture of this for us?

[drdd]

how do u take a picture of a 'grinding sound' ???

Originally Posted by BlazerLT

Can you take a picture of this for us?

[BlazerLT]

can you actualy read the thread and what I was responding to.

[Eriedipper]

Originally Posted by ginger444

I have a tube running from my rear axle onto the frame. Looks like a filler tube. How do I access and how do I tell how much oil may be needed?

Cheers

I would say the tube is a "breather/vent" tube to relieve pressure.

The filler plug in the housing or casing is usually also the level plug.

General rule for axles/differentials oil level is approx 1/3 full.

Hope this helps?