Rattling noise under truck

2003 4x4 tacoma. When i have my foot on the brake and shift from Park to drive or park to Reverse i hear a loud rattling noise, when i accelerate it goes away. Also every once in a while it feels like the truck is going into a higher Rpm without shifting, then when it shifts it slams into gear. Any help appreciated

 

Rattlin noise where? Front, back or under you? Best way to find out is to get someone to shift into the drive or reverse with their foot on the brake hard and be under there to narrow it down. Could be U-Joints, carrier bearing or a few other things.

 

Souds like its right under me

 

only thing under the driver seat is the front drive shaft.

Could be an old catalytic converter broke loose chunks or the driveshaft.

Vibrations are hard to track down when they are under the cab.

 

Yup best way to figure it out is to actually look at it while the noise is happening. Get a buddy or someone to help you.

 

When i tap on the Cat it sounds like something loose in it. Do i need a nee cat?

 

100% yes

 

if your front cat went bad the loose debris is beating up the rear cat, if the rear cat is also bad the loose debris beat up the inside baffles of the muffler.

If you can afford it replace both cats and the muffler.

 

You probably already checked this, but I've gotten a lot of rattling over the years from those heat shields on the exhaust, especially at idle.

 

Well, before you waste too much time & money...

Verify that your transmission fluid is at the correct level, check it with the engine warm & running. The fluid should be red.

I don't know what engine you have, but it's fairly easy to remove the catalytic converter to check it out. You'll need a couple of exhaust gaskets, and perhaps some new nuts & bolts.

I'm chasing the same type of noise, a rattly-ting-ring noise.

My truck makes the noise at a stand still in drive & reverse. I first thought it was the transmission, but I put the emergency brake on & left the truck in drive & the noise was coming from the second catalytic converter area. I pulled the cat, and it was fine & the heat shields were fine as well.

 

I had this a while back. Turned out for me one of the nuts holding the cat converter flange to the front exhaust past (sorry don't know the exact name) was going loose. Tightened it up and it was gone.

--Dan.

 

yeah my o2 sensor was loose again, tightened it on and the noise went away

 

Interesting, I hadn't thought to tug on my O2 sensors. I did notice that the upstream O2 sensor was missing half of one of the studs, but there was still a nut on it. Perhaps it's the source of my noise.