Engine noise (maybe spark plugs but not sure)

[Brainless]

Hi!<p>I noticed a strange noise yesterday coming from my i4 SOHC. It's a "tick tick" sound that we can usually ear when the engine is cold, but when I heard it, it was after a 3h highway trip so I don't see how this could be related to the engine temperature. Today I check the spark plugs just to make sure and I realized that the 3rd one was a bit loose so I tighted it up. I took a look at the plugs and there seems to be some brown stuff on it (not sure if it's rust...is this stuff nomral?). I've done about 20k km on those plugs, when should I change them? To you think this problem could be related to something else than the plugs (I haven't got a change to take a good look at the sound since I tighted it up today)?

[JWMotorsports]

It could be many things!
-Check your oil, ticking is usely your valve lifters.
-oil should be changed every 3,000 miles
-your oil filter I'd recommend every other oil change.
-make sure your oil isn't low!!!!
-If your hearing a metallic ping or something that sounds like loose change than it is detonation.
-in this case check your timing
-it could also be slightly cloged injectors, fuel filter or even a failing fuel pump or regulator.
-Spark Plugs
-I run NGK V-power copper core plugs. Mine are changed every 5-10K miles depending on plug condition.
-One thing you can do to smooth out the top end w/ the stock ignition is to close the plug gap up to about .030, was recommended to me by Corksport. It also helps them keep from fouling so easily.
-If the insulator on your plugs are slightly brown your fine. It means normal wear. However it also is a sign they probably need to be replaced. Check out the back pages in any Haynes repair manual for examples and explenations of plug conditions and wear or damage.<p>All in all doing the following may help your car out any way.<p>-NGK V-Power plugs gaped to 0.030
-Magnecore KV85 8.5mm Competition Plug Wires
-Accel Super Stock universal ignition coil
-Borg Worner brass terminal distributor cap & rotor
-BOSH replacement oxygen sensor
-Red Line 10w-30 Full Synthetic Motor Oil
-Red Line water wetter
-K&N Performance Oil Filter, I used a larger than stock filter.
-Pro Blend Engine oil addative<p>These will help your motor run MUCH cooler & smoother than stock. Not to mention beter emissions, fuel mileage & longer life for your motor!!! Summitracing shaved .2 off thier Mustang Cobras 1/4 mile times just by changing the oil to Red Line Synthetic oil!

[Runninit]

I think the same thing , must be the oil, and in more explanitory terms the post above mine by JWMotorsports is very informative , so there ya go

[Brainless]

oil and filter are relatively new.(3k km)