could be a broken catalytic converter. mine made the same noise. is your engine light on? if so has it been on for awhile? i did o2 sensors (all 4 of them) and new cats. the noise was the pieces inside that broke apart because the sensors were bad. it was expensive. it only made the noise when the truck heated up.

 

I too vote bad cats.

 

is there any way to check? I put a pipe against the cat and heard regular exhaust noise. the noise is loudest at the passenger fender well area. I hope the atf flush didnt cause this. It still sounds great you really have to listen to hear this noise....for now. what else do i need to remove to get the oil pan out? anything?by the way, thanks for all the help so far.

 

Ooo, Oooo, just thought of this...your oil pickup might be clogged.
Just remove the 18,000 bolts that hold your oil pan on and it should just slide right out of the way.
Then RTV a new gasket when you put it back on.
You may need to remove the steering stalizer.

 

thanks spike, ill get on it!

 

the cats make the noise the loudest when the accelerator is pushed and the engine is hot.

 

yeah, you cant hear it when you rev the engine and if you put a load on the engine, you cant hear it. it worries me though...

 

I am kinda with Spike on this one. If it didn't show up until after the flush, pull the pan and clean it out. Get a new o-ring for the pickup and replace while you have it out. You may be suprised at what you find. Rods won't tick, they will knock.

Mine developed a tick after about 3 oil changes running synthetic. I flushed twice, but it remained. I ran 10W30 in the winter, and it went away. I recently switched back to 10W40 and it has returned. I recently replaced the front cover gasket and front main seal, and now my oil pressure holds steady at 30PSI hot with 10W30.... no tick.

Check your pan for gunk.

 

there is metal in the oil pan. looks like pieces of a bearing. took it to a local mechanic, they think either crank or rod bearing. this definitely sucks!

 

Don't get too worked up yet. Bearing swaps aren't too bad if the surfaces arent damaged