Loud Lifter noise from overheating


Turbo Member
I apologies b/c this is kind off topic but I have a question about a 3.8 V-6 in my non-turbo '84 Regal.

I just picked it up a cheap winter beater that has 54,500 original miles! It ran great without any engine noise and I just gave it a tune up. On its maiden voyage (after it passed MA emissions testing), I brought it on the highway (65 mph). Almost immediately the Temp light came on. I drove it to the next exit (about 4 miles away) because I didn't want to pull over on the highway. I found a parking lot but right before I got there I heard an engine noise (not a knock but a noise). I pulled in the lot to let it cool down. When I started it back up I heard the noise again. It sounds like a lifter tap but much louder. I do not think it is a rod knock. Could I have collapsed a lifter from overheating? Any thoughts? I am going to change the oil to see if it makes a difference but I do not know if I damaged the engine? I believe it overheated because of a stuck thermostat.
Thanks in advance
On my 84 , I had a similar situation. I pulled a valvecover and discovered that the rocker arm shaft was snapped in 3 pieces. Was down on power big time and could not get out of it's own way!
Just for future reference, it was a collapsed lifter in number for #2 cylinder. Replaced the lifter and it runs fine now.