Knock. Knock?

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NickLS

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I've been reading about engines knocking and misfiring. What does this feel or sound like.

While at idle in my LS V8, sometimes the car has small shakes or slight convulsions. Is this knocking? it's not to violent, but I know what a smooth idle is suppose to feel like. I'm using 92 octane so it's not about the gas i'm using.. is this slight shaking or convulsions what is considered knocking or misfiring?
 
I have the same problem as we speak, something to do with spark plugs.
Is there any spark plug that can reduce this, or can I get the pcm reflashed to correct the problem?
 
I'm about to change out my spark plugs. This past weekend, I took my 01 LS V8 in to check for that burning smell all of us where talking about.. and low and behold... it WAS the valve cover gaskets... they where leaking.. so I got those replaced... I gonna replace my old plugs with some bosch +4 platinums.... but until I get the money i just bought a bottle of fuel system cleaner (fuel injectors, ports, combustion chamber, pistons) and put it in. Seems to be working good.. Less of that idle shake.. KD00LS, you might want to try some of that out before investing in new spark plugs (unless it's just about time to)
 
The factory often recommends replacing spark plugs every 100,000 miles (+/-). This is unrealistic for 90% of today's drivers who drive in stop-and-go traffic or short distances. It least to permature breakdown of expensive ignition components. A more realistic change interval is 60,000 miles. If your vehicle also has spark plug wires, have them replaced at the same time.
 
The subtle shaking of the car is a repeated misfire. I had this as well as a stutter into 5th gear. I had the valve cover gaskets replaced, new spark plugs and spark plug gaskets installed. So far I have not had any shaking or stuttering. I have a 00 LS. I hope this helps in some way.
 
SurfjaxLS said:
The subtle shaking of the car is a repeated misfire. I had this as well as a stutter into 5th gear. I had the valve cover gaskets replaced, new spark plugs and spark plug gaskets installed. So far I have not had any shaking or stuttering. I have a 00 LS. I hope this helps in some way.
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How much did all of that cost, and do you think I should just try some fuel injection cleaner, if so what brand?

or, what should I do?
 
well, it could either be that you are misfiring due to spark plugs. Do you ever smell a burning smell coming from the passenger side cowel? It might be that your Valve cover gaskets are leaking and getting into the spark plugs making them misfire. So that might be one option.. To have your mechanic looked at them and if need be replaced along with new spark plugs. Or option two: your spark plugs just went bad (I know that's a lousy choice of words -> "just went bad") with corrosion, deposits, or the gap is off.

I used Gumout Fuel System Cleaner on my car and it has been a smoother idle for me. Haven't replaced the spark plugs yet due to $$$..
 
well, i just had a spark plug and coil replaced yesterday and the check engine light came back on today
so, i removed that piece of :q and resoddered the wires, reset the pcm, no engine light, but it still shakes a little

im gonna have him check the gaskets , after i try some gum out fuel injection cleaner
 
also around 40-60, it shutters for a little bit until i let off the gas, if that helps diagnose the problem
 
I dont know how much it cost because I was out of town when my parents picked up the car. And the valve cover leak does screw up the spark plugs and coils. It took at least 5 visits to the dealer to try to correct the problem, and a visit to a local shop to do the work right.
I haven't tried fuel injector cleaner either before or after the gaskets were replaced.
 
KD00LS said:
so, i removed that piece of :q and resoddered the wires,
Click to expand...

Edit --nevermind...I saw where you had the ACT hack and got rid of it. Good thing.
 
LBK_LS said:
I've been reading about engines knocking and misfiring. What does this feel or sound like.
Click to expand...

A knock is going to sound just like that: a knock. IF we're talking about rod/crank knock that is. That's going to sound like a solid metallic thud every time you hear it.

If you're speaking in terms of knock as in "knock retard" via a knock sensor, most of the time that's not going to be an audible sound unless it's pinging or detonation. Detonation will probably be closest described as a backfire, and it could occur backwards out the intake. It's basically the cylinder mixture being ignited prematurely or too late. Pinging would be best described as the sound of bb's in a soda can.

About the only time a misfire is going to be audible is if it's strong enough to cause a popping sound in the exhaust.
 
I think I'm gonna get the injector cleaner, then check the valve cover gaskets
 
It's ususally one bottle per tank of gas.. you might have to use two (two tanks of gas w/ fuel system cleaner)..
 
LBK_LS said:
ACT hack? what's that?
Click to expand...

I could be confusing you with someone else. I was wondering what wires you soldered.

ACT - Air Charge Temp sensor. A lot of people modify the voltage to make the car think the air is colder to advance timing or add fuel. Really screws things up.
 
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