I have a strong metal to metal rattle under load at low RPM. I am determined to find it this weekend. Please post your results if you have any luck.

 

Just another observation...it happens only after the truck has warmed up...about 5 minutes. Also it does not make a noise @ anytime during acceleration. Truck is running fine also...no noticable problems just the noise/vibration.

 

it really sounds like my problem i had, read my post on page 1

 

I did check all the clamps and they seemd okay. I'm taking it back to the transmission shop in the morning just to have them give it the once over to rule out the tranny.

Thanks,
Jim

 

Went to the tranny shop today...tech had me put truck in gear and keep my foot on the brake. Gave it some gas until the noise started...he concluded it IS a heat shield on the passenger side. What can I use to rip the thing out? He said he was able to change the frequency of the vibration by pushing on it, but could not get it to stop.

Thanks,
Jim

 

Don't think it is a good idea to remove the heat shield, could melt something above the cats, it gets really hot under there. Mine made that noise at low speeds/rpms. Turned out it was an exhaust clamp that was too close. Loosened the clamp, turned it into another postition, noise was gone.
Since you have narrowed it to the heat shield area. If you can, loosen the heat shield and/or remove it, try bending the mounting bracket.

Just my opinion, the tranny guy bent your exhaust on the lift or with a jack. Unfortunately, the only fix for that would be a muffler shop heating and re-bending it.

Good luck.

 

**EDIT** Just saw your reply ********

I'm pretty sure I read this thread completely so here goes.... Did you jack it up, start it up and get underneath and listen? I was able to determine a blown out high flow cat immediately by going that route. Same symptoms and it got louder and clunkier the worse the guts of the cat discintegrated. And if it only happens when putting it into gear, you can chock the crap out of the rear tires and still be able to put it in gear while jacked up.

And if it turns out to be a blown out cat, don't worry, the noise goes away after it completely nukes itself internally.

Good luck.

Dan

 

Dan,

Thanks for the reply...I'm thinking you are right. Went to the muffler shop today and they cut the "Heat Shield" off the passenger cat. Did it free of charge...but the sound is STILL there. Weird thing is when I pushed on the cat with a crow bar while it was rattling...noise stopped. Had the thing cut off...now it still there. ARRRRRRRRRRRRRRRRRRRRRrr!!!!!!!

 

Try taking it to a shop and put it up on the rack, get in it and run it,I foung the noise on my 69 mustang that way, good luck

 

Thanks, problem is it only makes the noise when it's in gear...If I have it in Park or Nuetral...no noise.

 

find someone with a lift that you can run the truck, I found a problem on my 69 mustang that way, good luck

 

sorry didnt think it took the first time. opps