hello i got a 3.1 l v6 firebird with 105.000 miles on it , i dont know if its time to replace the timing chain because the haynes manual says: "if the engine has over 25000 miles on it ,its almost certainly of replacement"is that true or just a printing error? because i cant imagine you need to chage it after only 25k miles
thanks

 

I did mine at 80k , unknown previous history. It was really slack, glad I did it, and it ran nicer.

 

if its not giving you any symptoms to change it then i wouldnt unless you plan to tear into the engine and change gaskets, injectors, basically freshen it all up. I didnt change my chain originally untill about 109k miles. It was loose but then again it only takes about 5k miles and they can loosen up a bit anyways.

 

thank you
are the DNJ timing chain sets good or crap?
I bought one a long time ago for 35$ to fill my shopping cart at rockauto