Engine grinding noise? 89 240sx KA24E

[onosqv]

Hi, I noticed this in the last week that my engine makes this grinding noise when I start it up, kind of like metal on metal. It is noticeable on lower rpms and when idling. Sometimes it completely disappears, but usually pops up during start up, then will usually go away. Sometimes I will hear it when I park or idle.

Sorry it's not too descriptive, but it's an odd problem.

The last things I've done to it are oil change, which didn't fix the problem or affect it at all. Before that, I did a minor tune up: spark plugs, wires, distrib cap, rotor head (could I have not tightened the rotor head correctly?), pcv valve.

While I replaced the pcv valve, I had to move the throttle cables aside, which I replaced and readjusted.

Any input will be great before I have to take this to a mechanic.

Thanks!

[benemorius]

Do a search for "timing chain rattle"