pretty sure my motor in pinging

[tybardy]

I am not 100% sure as i have never heard a motor ping in real life. I looked up pinging on youtube for some sound clips and it sounds exactly like what my truck is doing.... a light clickng noise that gets faster with higher RPM's. It really seems to be doing it more and more these days so here are my questions...


How can i be sure that the noise i am hearing is pinging?

if it is; what is making it ping (i have a 91 octane BB tune and always use chevon premium so i dont think it is the gas... at least i hope not)

and how can i stop it?

 

[snowjay]

Pining is caused by the air/fuel mixture not burning evenly (or even too soon) creating a shock wave inside the cylinder which is the noise you hear. Several things could cause it, timing too advanced, too low of an octane, too lean of an a/f mixture or too high of cylinder temp. A bad EGR system could also contribute to the problem.

What are your engine temps like? Is this only happening under load? So when you let off and just cruise easy it stops?

I would go through this tank of gas and run 93 or higher next tank and see if that "fixes" it. Then if it does you can see if any of the other things can be corrected so you can go back to a lower octane.

 

[jomulk56]

It could be a fuel pump going bad too. With a tune a bad stock fuel pump has a very hard time keeping up if you are near 100% duty cycle.

 

[tybardy]

i already run 91 octane (cannot get 93 octane fuel in arizona) so if the fuel octane level is a problem then it would need to be re-tuned. however i doubt very highly it is a fuel octane issue.

I just installed new wires because i thought it might fix the issue, obviously it didnt.

As for some of your questions... it happens at idle and when accelerating. However i cannot tell if it is happening at higher RPMs as the muffler tends to drown out the engine noise at that point. Engine temps are always normal, never better then 210.

---------- Post added at 07:42 PM ---------- Previous post was at 07:41 PM ----------

i do not have my flip camera so i cannot get a good sound clip of the problem till monday but i am starting to get worried about driving the truck as the noise is ******* loud!

 

[snowjay]

Go to an auto parts store and get some octane boost.

Higher octane will almost always fix pinging, but I wasn't suggesting that as your long term fix, but it would let you know if what you are hearing is pinging or not then from there you could diagnose the root cause of the problem.

If it's doing it at idle that's odd usually it only happens under load. Sure you just aren't hearing the injectors firing? Or something else rattling around?

Look at your fuel pump as suggested and check it's pressure. If it's not able to keep up that would give you a lean mix causing detonation.

 

[tybardy]

Go to an auto parts store and get some octane boost.

Higher octane will almost always fix pinging, but I wasn't suggesting that as your long term fix, but it would let you know if what you are hearing is pinging or not then from there you could diagnose the root cause of the problem.

If it's doing it at idle that's odd usually it only happens under load. Sure you just aren't hearing the injectors firing? Or something else rattling around?

Look at your fuel pump as suggested and check it's pressure. If it's not able to keep up that would give you a lean mix causing detonation.

well i thought it was the injectors firing. I thought the noise was coming from the spark plug area so i replaced the wires with 8.5mm. I did the pluggs about 15k ago so its not those. The deal is, it has not always made this noise.

How do i check my fuel pump pressure?

 

[snowjay]

Usually there is a schrader valve on the fuel rail and you'd hook a pressure gauge up to that.


Also if you have carbon build up in the cylinders it could be increasing your compression contributing to the pinging.

Does it consume oil between changes?

You should pull the plugs and see what they look like. It will be easy to tell if it's a lean condition. Then you wouldn't have to worry about trying to check the fuel pressure.

 

[tybardy]

i can pull the pluggs, but my guess with less then 15k on them is that it is going to be hard to tell if it is running lean. What would the plug look like if that were the case?

As for the carbon build up, i also sea foam the truck regularly. but i suppose i can give it another go...

i just got back from the gas station... added a bottle of Lucas Octane boost and i think it lessened the noise (what i think is pinging) but its not gone... or maybe im just smokin crack... i dont know but it pisses me off

 

[COTahoeLS]

If it's at idle, I would suggest you to take a long ass screwdriver and play doctor on the thing in your driveway. By using the handle to your ear and the tip of the screwdriver to various parts of the motor and listen.

I used to live in Arizona for 8 years and tuning there was a ***** due to the heat, piss gas and other variables. How about heading down to the gas station by Firebird Raceway that sells the 100+ octane and throw a gallon or so of that in there? I'm not a firm believer of those octane booster bottles.

As for plugs, its kind of hard to determine just from looking at them BUT tell tale signs are: Brown is a good mixture, while is lean as hell, and black is of course rich as hell. I'll see if I can dig up an old link of plugs I used back in the day.

-E

---------- Post added at 08:21 PM ---------- Previous post was at 08:19 PM ----------

Found the link:

http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm

 

[road1will]

if you seafoam "regularly" you should also change your plugs regularly. you're supposed to change your plugs after seafoaming. i think that seafoam is loosening up carbon build up, depositing that shit on your plugs, and giving you a poor spark.