94 4Runner pinging issues

[Rud3dog]

Hi everyone I am new so bare with me if i sound a little lost . ok here is my problem I Have major pinging issues with this thing. I bought this 4runner about 6 months ago and i knew it had pinging issues but i thought it was a fuel problem. I have put premium in it and it still pings. the funny thing is when i run it in the morning it does not ping.Only when it reaches operating temp is when it starts. So here is a list of things that i have done. Oh and i am getting no codes at all so i really think some other sensor is out of wack

Seafoam 3X helped idle still pings

TPS replace and adjust no help

O2 sensors No help

Fuel filter no help

Checked timing 10 deg btdc as per fsm

Spark plugs wires and cap no help

Removed and cleaned EGR (what a mess) no help

Cleaned throttle body no help

I have a friend who has the same year so we swapped the ecu,afm,and distributor no help

Compression checked there all within 120 to 130 range

I replaced the water pump timing belt so everything is ok there. the only problem i have is the fan pulley bracket has got a bad bearing i thought it was the water pump going bad but it turns out it was the fan pulley. a question i have is can the noise from the bad bearing throw off the knock sensor to advance the timing. also it has 170,000 miles maybe a partially clogged cat. I don't know what else to do i'm lost any help would be appreciated. :gun4:

 

[Rud3dog]

I forgot it pings in the 2k to 3k rpm range if i punch it it stops also if i am at idle and tap the gas it pings or rattles bad for a second

 

[Hyde802]

What about running a higher octane gas?

 

[mattb]

I hear pinging used a lot on the forum. What exactly do you guys mean by pinging? Where do you hear it? I hear my valves rattling sometimes? Is that pinging? It did lessen when I started running mid-grade gas. Would it get any better if I used premium? Is that high of an octane ok for the 3.0?

 

[Rud3dog]

I have tried high octane and even octane boost and it didn't work the pinging is a rattle sound I am going crazy with thing its driving me nuts

 

[mattb]

With that amount of mileage I would expect a little bit of rattling. I think a majority of the 3.0have it to some extent. How annoying it is to you depends from person to person. Is yours really bad, or is it just bad enough to drive you nuts? Maybe you need to have your valves adjusted?
Mine rattles a little from time to time, and my friend who has owned a couple of 3.0 trucks said it was the valves. Both of his did it. He told me to use a higher grade gas, and it helped some. Now I just try to ignore it so it doesn't drive me crazy. My old Ranger used to do it too.

 

[run4yota]

loud or "clacking" valves are cause by excessive valve lash and/or wear. this is not pinging. pinging is a sound that resembles a chain dragging behind the vehicle and creating a pinging sound. it is caused by excess heat, too much compression, timing advanced to far, or a lean fuel/air ratio.

the root of the pinging sound is the fuel in the cylinders igniting before is supposed to on compression stroke. the technical term for pinging is "pre-ignition"

as we all know when gases (air) are compressed it excites the electrons moving around the nucleus and causes them to move faster and closer together. this causes friction between the atoms and thus heat. the basis of a diesel is compressing the gasses enough to create enough heat to cause the mixture of fuel and air to ignite. so when there is too much heat in the cylinder and the intake air is hotter it can cause the mixture to ignite upon compression. this can cause pining.

an engine running lean will cause it to run hotter and the pistons and cylinder walls will be much hotter as well regardless of the cooling system. this will cause pinging. when the engine pings and the knock sensor picks it up it rich-ens the mixture slightly and re****s the timing just enough to stop the pinging.

the timing being to far advanced will cause the same symptoms as pinging because it ignites the optimum point.

having low grade gas will cause it to "flash burn" which creates excess heat and thus pre-ignition.. what it really comes down to it excess heat being caused somewhere in the cylinders.. most likely timing and bad gas.. also it's summer so keep in mind that there's alot of heat which amplifies any problem.

 

[Rud3dog]

well the funny thing is it runs like a champ when cold. as soon as it reaches operating temp it starts pining. i just had the heads done so its ok there. it almost seems like something is causing the timing to advance. will a bad bearing in a pulley cause the knock sensor to advance the timing. i hear that the sensors dont kick in untill it reaches operating temp. could there be a short somewhere? i am 99% sure its pinging its not valves or injectors. the motor does leak oil at the oil cooler. The truck runs great it is really annoying cruising on the highway at 2500 rpm it pings sometimes for a steady 10-15 seconds i am really concerned cause i dont want the engine to go bad.

 

[run4yota]

your mass airflow sensor has a temp sensor that reads the temp of the air going into the engine. when it's cold it says i'm cold, the air is cold, i need more fuel because the air is dense. once it warms up and the air it's breathing from the enginge compartment is now hot it senses this and says the air is thin, i need less fuel. when it does this it leans the mixutre out for optimum fuel milage. what it doesnt realize is that it's actually leaning it out too much which is causing a hotter flame in the cylinders and creating excess heat. this is what is causing your pinging. there are two ways around it.. re**** your timing, or get better gas. if there is something causing a sensor to get a false reading you would get a CEL and know that something is wrong, if no CEL is detected then you prob just have bad gass or timing. let me know what you find, i might have more infor the more detailed you diagnose it or the symptoms.

 

[Rud3dog]

I have tried better gas and fuel additives It was no help at all. I have also re****ing the timing i can put it at 0 BTDC and i get no pinging, but i also have no power at all,. the only thing i can think of is maybe the fan pulley bracket has a bad bearing and it is making noise could that affect the knock sensor? could it be telling the knock sensor to tell the computer to advance the timing?
Also maybe a partial plugged CAT. What about maybe a short somewhere. ,I just did a engine flush. I checked and replaced the thermostat it was fine. I am totally frustrated with this. I can deal with a occasional ping but this is too much :sniper: I wish this thing could run like when its cold all day. If there is anything else i can check PLEASE HELP.............

 

[Rud3dog]

I Still have the problem. HELP!!!!!!!!!! lol