i recently changed the spark plugs in my 3rz 4runner, and i've noticed that under modest accerlation (ie not enough to cause a downshift), a slight clicking comes from the engine, which hadn't happened before. based on what i've read, it seems that this is likely to be engine pinging, but i'm wondering what you guys think?

some extra info - the spark plugs put in were oem NGK plugs, but i gapped them myself to the factory spec (.032 i think).

thanks for reading this

 

maybe one of the plugs is loose?

 

ill second a plug is loose

 

Well, either you have pinging, or you now have spark arcing to ground... does it feel like its running any different??? missing a touch??

 

i dont know if its the same thing but after i got mine changed i noticed a slight change in the engine "hum" at idle (also had water pump and timing belt done with this) dont know if the noise is also spark plug related

 

I had the same ticking at ide and it was Arcing.

 

thanks for the replies guys

its definitely fine at idle, so i'll try tightening the plugs and see what happens. if its arcing, what can i do to fix it?

 

Find the arc and solve the break in the system. Try doing it in the dark so you can see the spark. Don't over tighten your plugs, you're just looking for one that's gotten itself loose and don't forget the antiseize.

 

I believe the manual is Wrong on plug gap. As mine was.
Called the company that you are using their plug. Like NGK, Denso and etc.

I went through the same thing with my plugs, manual said .031 Wrong. It is .043. As per NGK.

 

.....

 

thanks for the replies. just an update - i tried installing the factory densos, which are pre-gapped, and the ticking is still there. i'm thinking its actually pinging since it only occurs after the engine warms up.

the other thing i put in was a k&n air filter - could this have anything to do with the issue, by maybe throwing the fuel/air mixture off?

 

is it possible the oil off the k&n filter fouled up the MAF?

edit: just to clarify, this problem only occurs under load and not in neutral.

 

Go out in the dark, vehicle running and nice and hot.... get a spray bottle that is adjustable to a FINE MIST.... mist around the spark plug wires and see if you get any arcing, most likley around where the plugs are.... because it is dark you should really be able to see it if thats the case....

How many miles on the truck? and are the wires original?

 

its a 98 with 60k miles, and the wires do look original. if its arcing, wouldnt it do it in neutral as well?

 

Not always.... maybe only under load.....

 

ok thanks, im going to try that tonight. its definitely not pinging because i filled it up with 91 octane and the tapping noise is still there.

 

Keep us posted!

 

ok thanks for your help bob, i checked for arcing and i didnt seem to see any, but i did try throwing in a new oem air filter (those paper toyota ones) and the problem went away. i have no idea why an air filter would cause a tapping/ticking noise, but now its gone. i'm still kind of baffled.

 

General spark plugs will not cause this problem and factory dealer plugs come pre gapped.

Sound like your engine had pre-detenation(or pinging), this is caused by higher than normal tempetures in the combustion chambers. What it is doing is, igniting the air/fuel mixture b4 top dead center when can cause serious damage.

The KN air fiter allowed extra air into your engine leaning the mixture out. A lean mixture results in higher engine temps causing your ticking sound.

Did you try resetting the ECU after installing the KN? Disconnect the ECU fuse in the eng. bay for 10mins and then drive it ,so it will "relearn" the additional air.