Knock

[Puscifer]

I changed out my spark plugs the other day, first time since i've aquired the vehicle. the old ones were black as sin as it's dumping fuel like crazy. But, what disturbed me is all 4 of the spark plugs were lose, i mean 1-2 lbs of torqe pulled the ratchet to no pressure. So, I replaced them and tightened as they should. Now, i've got a baaaad knocking noise. Anyone experience anything like this or any reason for the spark plug change out to do this? I also took the old dinky wires off and put some 8.5mm's on. Thanks in advance.

*edit* NGK's of course were the take out and put in. - Advance auto parts is going to stop selling magnacore* wires soon, they're at no more than 60.00 bucks their stores. MSRP of about 98.00 is good savings!

 

[delta448]

Which heat range plugs did you put in and how much did you gap them to? I'm guessing you put in a hotter plug than what you had previously. If you run more than 16psi, I would recommend using NGK 7's, more than 20psi I'd say 8's.

 

[pooker]

Did you put the spark plug wires on in the correct order?

 

[Puscifer]

Standard NGK's. Threw the boxes away but they were the bottom line of NGK. that's offered for our cars. Also the same thing that was taken out. .(0)28-.(0)31 as manual specifies.


yes of course. from left to right on the pack, 1-3-2-4.

 

[delta448]

Standard NGK's. Threw the boxes away but they were the bottom line of NGK. that's offered for our cars. Also the same thing that was taken out. .(0)28-.(0)31 as manual specifies.

If you have the NGK BPR6ES, which is the "bottom line", I really think you should take them out and try BPR7ES. Gap them at 0.028. The 6's are too hot for most people running an upgraded turbo or very much above stock boost levels. Also, if you live in a hot climate and don't have a good intercooler (or meth/water injection), you can have more knock issues with a warmer heat range plug. Try the colder plugs first, they're a cheap fix. If that doesn't help your problem we'll start going through the other possibilities.

 

[hackish]

Be careful when reading sparkplugs. The colour of the sparkplug is not directly an indication of leanness or richness. The colour is an indicator of heat. You may be running the correct mixture but a plug that's too hot or cold. A lean mixture will generally be hotter and a rich one colder but the best way to determine the AFR is through a wideband gauge. They're fairly cheap these days and a good investment.

As for finding your plugs loose that is not really a sign of knocking or detonating. Broken electrode ceramics, aluminum specs on the ceramic and groundstrap are signs of this. Plugs also have a crush washer so when you install them the first time you usually snug them up and give another 1/2 turn. I usually just use the limit of my wrist strength turning the ratchet.

-Michael

 

[Puscifer]

Yeah, they're the 6es'. I'll order some 7's in today while i'm at the parts house. Any place i can get cheap NGK plugs? i'm getting charged about 5 dollars per plug @ bottom line atm. Yes, it's very tropical where i live at. i have a big FMIC atm. I just don't understand why the sudden change to the motor after i installed the new plugs. back to the beast i go.

 

[daren_p]

Did you verify the gap on the new plugs (gap the plugs) before you install them? What did you gap them at? What boost are you running? You can pick up a set of plugs from most DSM vendors for like $10 for the set of 4 (check the supporting vendors section of this site).

 

[hackish]

If the gap is too open it will cause misfires, not white plugs. Like everything it's a matter of finding the happy medium. Too small of a gap gives you a really hot but short duration spark. Too wide of a gap gives you a longer cooler one provided your ignition system is able to supply enough power to jump the gap. AT higher boost levels the ionization potential is lower and it requires more juice to make jump the gap.

-Michael

 

[Gs Dewd]

Standard NGK's. Threw the boxes away but they were the bottom line of NGK. that's offered for our cars. Also the same thing that was taken out. .(0)28-.(0)31 as manual specifies.


yes of course. from left to right on the pack, 1-3-2-4.

Now isn't the firing order 4123 not 1324?

 

[delta448]

Now isn't the firing order 4123 not 1324?

The stock ignition is a wasted spark system. Cylinders 1 and 4 fire at the same time, 2 and 3 at the same time.

 

[Gs Dewd]

As far as the ignition is concerned, you're both right. It doesn't matter since the stock ignition is a wasted spark system. Cylinders 1 and 4 fire at the same time, 2 and 3 at the same time.

But if he wired it how he explained then 1 and 3 are firing from the same coil and 2 and 4 are firing from the other coil. Instead of 1 and 4 then 2 and 3

 

[delta448]

Sorry, I just read that too fast. Should've looked a little closer I guess. Good catch Dewd. I edited my post. The correct firing order is actually 1-3-4-2.

 

[Puscifer]

1-3-4-2 eh.. i'll give that a shot this afternoon, got her ripped down replacing the timing componets now.