I am getting what sounds like pinging at all speed ranges and gears. It sounds like just one or two cylinders, and happens at light throttle more than heavy throttle.

It is a '97 A4, 55K miles; runs very strong. No error codes.

New Magnacor wires and NGK Iridiums. I ran Techron through it, and no change.

I put an induction timing light on a couple of the wires, and noticed that the flashing was erratic, sometimes not flashing.

Is this a case of the coils getting weak?

Has anyone experienced this? Any way to check the coils?

 

Please describe what you call pinging! A timing light will not detect pinging but it would detect a cylinder misfire.

What codes are you receiving when you bring up the DTC'c using the DIC?? Please list all of them on this post. Is your check engine light ever coming on?? Does it come on during the "PINGING" ??

I do not believe that you are hearing engine cylinder preignition/ Knock or as you call it PING. I am not doubting your word but would like to make sure it really is cylinder preignition/knock rather than some other problem.

It could be a number of things that sound like it:

Exhaust manifold or header leak.
Sparkplug being loose.
Sparkplug wire being loose and allowing the spark to jump and arc.\

If your check engine light is coming on when the event is occuring, read the codes and see what codes are being displayed. You can pull the codes up while the car is being driven. Just be CAREFUL and dont wreck!

Bill C

 

Carbon.

 

Hi Bill

What I hear as "pinging" is what I have heard on many different cars over many years, except where before it sounded like marbles in a tin can, mine sounds like ONE marble in a tin can.

I have been around engines and cars many years, so I am not new to this.

The only reason I put on an induction light was to try and zero in on anything to give me a clue. I know the light will not show pinging, but it will/should show a misfire.

My theory is that if the plug is not firing, the high compression will detonate the mixture and cause the pinging.

However, I have ABSOLUTELY NO CHECK ENGINE LIGHT, AND NO ERROR CODES (except ASR 1571).

I replaced all the plugs, made sure they were torqued ok, and it still does it.

The only real "mod" is a K&N air filter, and breathing holes cut into the air cleaner cover.

Is it possible the extra air flow is leaning out the mixture more than it can compensate for?

Also, on the issue of carbon - I used to get carbon on my musclecars back in the '60s, but I find it hard to believe with current engine technology the LS1 will carbon up. Even my C4 with 150K miles was clean when I did a valve job.

So, maybe, but seems a stretch...

Anyway, any thoughts are helpful

 

The only thing I can suggest is to do a full scan with some SW like HP Tuners, or LS1 edit and see what the KR count is. I believe the KR has to go above 10.0 or 11.0 to log an error code. Don't quote me on that. Most generally after 3 it starts cranking back the timing. I don't believe a mis-fire or dead plug as for the most part those will log a mis-fire code as the O2s will pick it up.

Lean may cause it, could be a bad or dirty MAF.

At WOT open loop I kick one or two KRs around 4800 RPM and up when she is pulling hard. Normal driving or even pulling hard in closed loop, not a single K. I know mine is due to the mods and I need to calibrate my MAF. I have all the bolt on mods. LG long tubes with 3" cats, Corsa Indy system, Halltech snorkle (early style) Modified Stock MAF, Halltech ends, removed screen and removed plastic supports. Z06 intake.

I have logged a few runs with HP tuner SW. I need to clean my MAF first (been 3 years since I did the mods to the MAF).

97-98 LS1s seem to be more prone to KR for some reason. At least that is what I have heard. In my case I know what it is because it is obvious with the Scans I have done.

I am going to put a wide band O2 sensor on to get a more accurate AF reading before I do any re mapping on my MAF.

I don't think it is mis-fire. Spark and header leaks sound nothing like Ping and I think you know Ping or pre ignition.

Finde some one with HP tuner for your car and have them run some active scans.

 

Sadly it's not a stretch...

The main problem the LS1 has is that the PCV system pulls oil out with the air and injects it back into the incoming air stream. Many have put catch cans or filters on the PCV line to deal with this problem. The result is that some oil is actually being sucked into your engine with the incoming air charge. Over time it builds up carbon on the piston tops and you get hot spots. The is an engine decarb procedure on this site using a GM top engine cleaner solution.
My '01 had pinging on hot days and doing the decarb cleared it all up.

So... I'd try that first (it's cheap and easy) and see if that clears it up.

Good luck...

--Bill

 

Bluedragon-

Thanks! I will also check out the MAF and see if that helps

 

bletour2001

Ok, I can see that about the PCV. I have seen on the forum something like a RB44 (?) that is supposed to do wonders, so I will try and locate it and run it through

Thanks!

 

No problem..
If you look at the top menu bar and select "Other" there is a Tech Tips section. Under there is the decarb procedure. I used two cans of the GM Top engine cleaner which you can get from any GM parts department. I think it was around $6 a can. You want the liquid. Basically you pull out the PCV pipe, insert funnel and slowly pour the stuff in while the engine is running. (You might need someone to help keep it going). At the end of the second can shut it off. Let it sit overnight. Start in morning and watch the SMOKE!!! Drive around until the smoking stops. That's pretty much it. I/Most also change the oil afterwards since it is probably totally contaminated.

--Bill

 

Definately do a oil change after, warm it up and change the oil, run about a week on the new oil change and do it again! That stuff is pretty hard on the lower end. You will dilute and rinse it with the first change, Then the second will pretty much clear it.

 

I just want to say "Thanks" to everyone that responded with tips and hints.

Makes this forum that much more enjoyable!

 

Please let us know if the decrb procedure works to clear up your problem. It will be interesting to see.

Something else that I remember hearing about was one forum member had a problem with his CAT and the catilist inside the converter was damaged and made a pinging sound.

Bill C