Im hoping somebody has had this problem before. A few weeks ago my 92 Camaro (305 TBI Automatic Trans), started knocking like I threw a rod or something. I took it home and my husband and I looked it over. We noticed that the knocking didnt knock in rhythm like it should if the engine was blown. We both though that maybe it was the tranny. I went under and checked it. I found that one of the three torque converter bolts was a little loose. Not much but enough for me to want to tighten it back up. So I tightened it up and made sure the others were good. I expected to not hear the knock when I started it. No such luck. I was told by a friend that it might be the exaust manifold gasket. Could that make it knock like that? If not what could it be?

It knocks when you start it (in park) and every gear except reverse. Reverse sounds great. After driving on the highway awhile it seems to go away. Ive noticed it knocks when excelerating the most. The tranny looked great when inspected but Im not ruling that out. Any ideas?

 

and you are sure its not the flexplate?
i had a car that did the same thing
it made noise in 3-2 and park.
1 and reverse were OK.
if i used BP gas, no noise...
it was weird, and made me think something was seriously wrong.
it wasnt until my uncle came over and listened to it that we figured it out.
he sat and listened to it and was like "ive heard this noise before, i cant place it but ive heard it before"
after a few minutes he said check the flexplate and sure enough one of the bolts was halfway un-done, the others were all slightly loose.




can you place where the noise is coming from?
front - back - left - right - top - bottom?
also, is it a "knock" a "klunk" a "tick" a "tap" or a "thump".
klunk is lower pitched and heavier
ticks are high pitched. often metallic sounding.
taps are mid-pich and clear
thumps are muffled
knocks are, well, knocks.

 

We took the exaust manifolds off and replaced the gaskets. One was pretty tore up but not so bad youd think it would cause a problem but it did. We replaced the gaskets and that fixed the problem. It sounded like a rod was thrown except the rhythym was all wrong for that to be the case. The conclusion we came to is that there was such high pressure flowing out the exaust that the pin hole leak was forcing exaust out. The pressure of the force made it sound as if it was knocking. Anyways....problem fixed!!!! I hope this helps someone....someday....when they think theyve lost an engine and find out that theres hope. Could be a flywheel....loose tranny....loose starter or many more. Dont loose hope and track that puppy down.

 

Oh.........and thanks Red Dragon for the input!!!!