First, I want to say hello to all. I troll this forums a lot and really enjoy reading what you all have to say.
I purchased my GTA in June of this year and this is what i know about it.

5.7L 350 with zero engine mods.
700R4 w/shift kit and possible higher stall converter. I do not know how to verify if the converter is aftermarket but the gentleman I bought it from thought so.
New cat back exhaust
Performance chip
Posi rear-end and different gears other than stock. I apologize once again for not knowing what they are.

With that out of the way I must say that my daughter passed her drivers test and promptly asked to drive the TA. What is a dad suppose to do...

She drove it approximately 20 miles in 2nd gear. When she got where she was going the overflow cap blew off and steam was rolling out of the hood. I was called to the "scene of the crime" to find tiny brass looking shavings in the anti-freeze after I filled it up. It also looked dirty.
After bringing the car home and driving it, it developed a "rattle" and I noticed a drop in oil pressure.
I am a novice. This car was something I have dreamed about for a long time and I really want to learn how to make it perform better. So now is my chance. I just didn't think it would be like this.
So I am wondering where to start in diagnosing what is making the "rattle". It appears to be in the top of the motor so i was thinking lifters? Any thoughts or suggestions on "how" to properly diagnose would be great.

 

Start by getting a very long screwdriver. Fire the engine up, let it settle into a steady idle, then use the screwdriver as a stethoscope, handle to your ear. First listen to one valve cover, then the other. If they sound the exact same, then kill the engine, put the car up on jack stands, re-start it, and listen to the oilpan. Then report back.

 

Sorry to read your pain. I also have a daughter that's learning to drive. I let her drive my heavily modified IROC for short drives but, I always ride along with one finger on the kill switch!

Now is a good time to replace and check the anti freeze and the engine oil. If the car was over heated, do you see any signs of milk shake brown oil in the anti freeze? Next, pull the dip stick. Any sign of water drops or that same milk shake color (mixed oil and water) on the dip stick? If no to both, warm up the engine to operating temp, shut it down then change the oil and save the filter, set it aside. Once the filter is cool enough to handle, slice it open, peal back the filter flaps and look for gleaming metal shavings. If none, good. If you find some deep into the pleats, suspect bearing or rotating assembly wear. Should you find small metal fragments dont panic. Wear is normal. Perform another oil change relatively soon thereafter and go through the same diagnosis.

If the anti freeze system has been or was neglected, you might be seeing scale and rust in the overflow tank. Hopefully, it's not the oil+water milk shake of head gasket death. Both are treatable.. A dirty cooling system can be flushed, and in your case it might be wise to have that service performed at a reputable shop the first time.

The three things that bother me about your post is that it was, 1) run in 2nd for 20 miles, 2) it was boiling hot when she called "Dad" and 3) it has a rattle noise following 1 and 2. Does it also now have a slight miss?

Lastly, following this event I would suggest a transmission service. Fluid and filter change. Being the car is stock, the trans fluid got good and hot too. Ouch!

Once your back on the road, take your daughter to a car show! Let her drive, you ride shotgun. Happy motoring and good luck

 

I agree. I would also recommend checking the oil to see if there is any debris in it. A rattle and loss in oil pressure I would normally think towards a rod knock hopefully it's something a lot easier to fix.

I've also heard the using a timing light to figure out what it is. If the noise happens at same rate of flashes it's valvetrain if it's double the light flashes it's probably assembly issues.

 

Hate to say this but overheating it that bad and lose of oil pressure is not a good thing. Shes going to have to come out and gone through..sorry for your pain!

 

Well thank you for your replies. We have been packing for our move to Tampa Florida area so I have been letting the car sit. I did the long screwdriver diagnostic and you can feel the "noise" through the screwdriver. It is hard for me to say what side valve cover I can feel it best from. But I did think the passenger side was more prevalent.

As far as the motor tear down...I don't feel too bad. I bought the car so I could learn more and I have always wanted to do a tear down. I have always fixed my own...just never this drastic.
Once I get to our new home I will settle in and try to do a better job isolating the "rattle".
Oh, I did not notice or feel any skip at all. That seems to be spot on.

 

Next step is to pop the valve cover, inspect for damage. Also, pull the dipstick, wipe some oil on your finger, smear it with your thumb, then hold it in strong sunlight. See any metal reflecting?
None of the rockers should wiggle any more than the others. This would be an easy give-away.
If you find no metal in the oil, try an oil change, with 10w30, and see if the pressure comes back.

 

Well I was able to follow some of the advice you have given me.
With the car started, I used my large screwdriver to try and "hear" the noise. What I found is nothing really distinctive. I put the screwdriver on each valve cover and it feels and sounds the same. While doing this, the "rattle" started being consistent with the idle of the motor.
It is a very loud tick. I could actually feel it with my hand on each of the valve covers and on the plenum. As a few minutes went by the car idled down and the noise became inconsistent again. There were actual small intervals where the loud tick was not there.

So I am not sure what I should do besides start to tear it down. I did record a ten second clip.

Wondered if you have any further thoughts. Thanks for the help.

 

I forgot to give more info. I checked the oil and it was normal. There was no abnormal discoloration or smell. There was no moisture.

 

I've heard sticky lifters before in my V6 cars and slight piston slap in my 2 cycle dirt bikes, but that's definitly pretty extreme. I'd start with the valve covers if that doesn't show anything I'd just yank it out and throw it on a stand. I'm leaning more towards rotating assembly issues with that much knocking.

If anything tearing it apart for new bearings, rings, seals, etc wouldn't be a bad thing after prolonged high RPM and heat not to mention our motors aren't the most pristine anymore being there 18+ years old.