This Is Probably...Not Good.

I might get kicked for this, but I had a reason for not caring (a lot.) I thought it was a loose heat shield.


So, around mid-May, my truck would make this "rattling" noise upon startup when cold, would go away after 10-15 seconds, and come and go from time to time. It sounded very familiar to the sound my car made when a heat shield for one of the cats was loose, so, I dismissed it. It hasn't really gotten any worse or better, but sometimes it does it when it's warm, etc. Sometimes, if I put it in Drive, it'll slow down to pace with the engine at idle. It doesn't affect how it runs, or how it drives, it's just annoying.


It's not a loose heat shield, so, I'm thinking it's probably the flexplate? The transmission was replaced, and it could have been damaged, I guess.


What do you guys think?

i had a noise on my 78 after putting in a new clutch, sounded like a rod knocking. turns out it was the inspection cover was loose. it very easily could be that simple.

Start with the simple thing. Check all the heat shields, covers, skid plates, etc...

My 93 Flex-Plate done messed up already I was thinking like you or that it was the heat shield till the flex-Plate fell down remove the trans inspect cover and look up there at night with a flash light I bet your going to find cracks around the bolts. Should we bet money on it Merlin will cover my bet? LOL

GMCTRUCKS wrote:

My 93 Flex-Plate done messed up already I was thinking like you or that it was the heat shield till the flex-Plate fell down remove the trans inspect cover and look up there at night with a flash light I bet your going to find cracks around the bolts. Should we bet money on it Merlin will cover my bet? LOL

As good as it is to see you GMC, the answer is no. I'm broke.

1993GMCSierra wrote:

I might get kicked for this, but I had a reason for not caring (a lot.) I thought it was a loose heat shield.


What do you guys think?

I think you should figure it out ASAP.

Like it was mentioned earlier. Start with the simple stuff.
Crawl under it with your rubber hammer and start tapping. Find the rattle.

GMC had me going.. i didnt look at the name and thought it was william saying his flex plate fell down.. i was thinking that that really isnt possible without noticing it.. the crank bolts and the Tc bolts would have to back all the way out at the same time or snap at each end.. and even then the Tc would still hold the flex plate in place cuase the crank seats in the Tc