Hey Guys,

I have a strange noise coming from my truck, and was wondering if you guys could help. Its from under the hood, from the front right side, and seems to only happen when cold. It also only happens when I have the break depressed, like something is vibrating when the RPM's drop really low. I can almost picture that AC canister under there vibrating, but have no way of knowing for sure....I took a vid of the sound...better than trying to describe it! Its off my phone, so you might have to turn up the volume a bit.

http://www.youtube.com/watch?v=W6u_l...layer_embedded

Any thoughts would be great!! Thanks!!

 

Only happens when y ou hit the brake?

I think it has to be related to the hydrobooster... How's the power steering fluid level? (air bubble going through hydrobooster?)

 

yeah, seems to be. And its also only if its pressed down so much. If i am barely on the brake, then it doesn't seem to happen, but i couldn't swear to it. I'll test it out a little tonight and see if it will happen under other circumstances.

I haven't looked at the PS fluid in a while, but will check it for sure!

 

Ok, so i was wrong....about many things. lol. It doesn't only happen when i am on the brake. If i am just idleing in the drive, and i move the wheel back and forth, the RPM's will dip and it will make that noise. The RPM's are also dipping when i am on the brake and turning the steering wheel....so i def think its a vibration when the rpms get below a certain level and vibrate the whole truck. What are these trucks supposed to idle at anyway? seems like it idles @ 750 and then when it drops down near 700, it makes this noise....

oh, i did check my ps fluid, and it was indeed low. Added some to it, and have driven around on it for a few days, but it hasn't helped...

 

I still think you have air in the system. I think the dealer has a purge process where they apply vacuum to the PS Pump and run the wheel back and forth.

The other thing I'd wonder about is the belt and tensioner.