I WAS AN IDIOT AND DECIDED TO SHIFT INTO SECOND GEAR IN AN AUTOMATIC WHILE GOING! THE CAR STARTED TO DRAG AND THE CHECK ENGINE LIGHT CAME ON AND I STARTED HEARING RATTLING IN THE ENGINE! THIS WAS JUNE SINCE THEN,  IT CRANKS BUT DOESNT TURN OVER! IV'E REPLACED THE BATTERY AND IT HELPED A BIT SINCE MY LAST WAS DEAD BUT THE ENGINE KEEPS EDGING ITSELF! A FRIEND SAYS THAT IT COULD BE A PUSH ROD AND ANOTHER SAYS MY TRANS COULD BE LOCKED! IF ANYONE CAN HELP I WILL APPRECIATE IT ALOT!

Well first hello and welcome to the site. Second why are you shouting and third how fast were you going when you shifted into 2nd gear? Can you be more specific about the rattling sound or post a video so we can hear the actual sound that she is making? When you stopped was there any fluids leaking from underneath the car, like oil or antifreeze?

Agree with Wrongway's questions but wanted to say 

 

Were you able to drive the car home? If you can hear the starter (wirrrr) but car is not turning over.  Starter Gear may not be engauging.  Agree with Wrongway, we need a whole lot more info to help.

No there was no leaks no i couldnt drive it home and the car isn't starting at the moment so i can show the rattling sound! I think its a push rod 

14 hours ago, Annihila said:

I WAS AN IDIOT AND DECIDED TO SHIFT INTO SECOND GEAR IN AN AUTOMATIC WHILE GOING! THE CAR STARTED TO DRAG AND THE CHECK ENGINE LIGHT CAME ON AND I STARTED HEARING RATTLING IN THE ENGINE! THIS WAS JUNE SINCE THEN,  IT CRANKS BUT DOESNT TURN OVER! IV'E REPLACED THE BATTERY AND IT HELPED A BIT SINCE MY LAST WAS DEAD BUT THE ENGINE KEEPS EDGING ITSELF! A FRIEND SAYS THAT IT COULD BE A PUSH ROD AND ANOTHER SAYS MY TRANS COULD BE LOCKED! IF ANYONE CAN HELP I WILL APPRECIATE IT ALOT!

Well, first things first welcome! Next I doubt shifting into second caused your problem or there’s more occurred than just shifting into second?! Why?  You should have a 4t65e tranny. If you tried to shift into second at to high of an rpm it would not happen until the rpm’s came down to the rpm window. Than it would be a very abrupt occurrence. 
So start from zero!  Will presume you have charge battery! Connect a pressure gage to the schrader valve on the fuel rail, turn the key on, but don’t start. What pressure do you have? If you have adequate pressure proceed to spark. Pull a spark plug boot at the coil pack have someone crank the engine or use a remote starter & see if you have spark. Check all 6 wires. If that all checks out as good you’ll need to next check the valve train, which means pulling valve covers & or check the torque converter. It doesn’t matter which you check first. Why the torque converter? I suspect that’s what you may have damage. Those are a lockup converter. If you were going fast enough to be in lockup, which is overdrive, something may have occurred that damage the converter inside. That damage is what you may hear rattling & could keep the engine from firing. 
Try those things & let us know what you find.

Edited September 17, 20232 yr by Last Indian

 

19 hours ago, Annihila said:

 

I apologize! I should have asked, do you know what code it has set? Before you do any of the things I mentioned. If you don’t know you need to get someone who has a scan tool & find out. That will be the starting point. There has to be a code set since you said the engine light came on. This is the first task that needs done.

p0300 is the code random/multiple misfires

Ok, when you downshifted what happened at that very moment? Did the RPM spike, did you feel more power from the engine or did it fall on its face. At this point I would tend to say it’s not push rod related, but we’ll see as you move forward. 
How many miles on the car? Original cat? 

From your dash picture, you need to tap the pin back in that holds your shift lever on, before it falls off.

i didnt peep the rpm when i did it but it fell on its face yes! 119k miles on the car and yes it has the original cat

2 hours ago, JUSTA6 said:

From your dash picture, you need to tap the pin back in that holds your shift lever on, before it falls off.

?

2 hours ago, Annihila said:

i didnt peep the rpm when i did it but it fell on its face yes! 119k miles on the car and yes it has the original cat

?

You have not resolved the issue I presume?! So many things can cause a p0300 code which is indicating multiple cylinders are misfiring. One of those causes can be a bad cat! You say it started to drag, so if the abrupt downshift caused enough increase in pressure to a already aged & compromised cat it could have caused the cat to crack! If that happened it usually blocks a large portion of the passages. This blocks air movement out of the engine, which will not allow it to start. Also a cracked/broken cat will rattle. So try dropping the cat at the back exhaust manifold. See if the engine fires. If it does the cat is probably the main problem. DO NOT run the engine for any length of time with the cat off. It is very likely the engine will not even want to stay running due to the lack of any back pressure, 3800 are fussy about back pressure due to the fire cycle.

Let us knows what happens.

Edited September 20, 20232 yr by Last Indian

On 9/20/2023 at 5:02 PM, Last Indian said:

You have not resolved the issue I presume?! So many things can cause a p0300 code which is indicating multiple cylinders are misfiring. One of those causes can be a bad cat! You say it started to drag, so if the abrupt downshift caused enough increase in pressure to a already aged & compromised cat it could have caused the cat to crack! If that happened it usually blocks a large portion of the passages. This blocks air movement out of the engine, which will not allow it to start. Also a cracked/broken cat will rattle. So try dropping the cat at the back exhaust manifold. See if the engine fires. If it does the cat is probably the main problem. DO NOT run the engine for any length of time with the cat off. It is very likely the engine will not even want to stay running due to the lack of any back pressure, 3800 are fussy about back pressure due to the fire cycle.

Let us knows what happens.

ok will do thanks i'll let yall know what happened

On 9/20/2023 at 2:39 PM, Annihila said:

 

?

Stop your vid at :24,   the pin sticking up from the lever on the right side of your steering wheel needs to be gently tapped back in.

2 hours ago, JUSTA6 said:

Stop your vid at :24,   the pin sticking up from the lever on the right side of your steering wheel needs to be gently tapped back in.

yea i saw it back then