Can someone describe what this sounds like? When I go WOT, there is a strange ticking noise that comes from the engine. Only happens at WOT, never any other time. Or is this KR? What does that sound like? What are the differences?

How can I fix this? The car has 5,500 miles on it and has always had 93 octane in it. Can the dealer fix this? Would new plugs and wires help? De-carb the engine? Any advice would be greatly appreciated. I take it that if I am getting pinging/knock, my car isn't performing at its peak...

I have searched the archives and found some info, just looking for a few more answers. :) Thank you guys for your help! :D

Patrick :jester

 

Mine does this to. On a dyno you can see the glitch in the power curve where the knock sensor kicks in.

Mine is more prevalent at high RPM's. I will fix mine with tuning. I am told that all this is due to running a lean mixture. I took out my MAF screen and I am told that this is the culprit.

So maybe yours is the result of a lean mix that only occurs at WOT.

Good luck

 

This is common but needs to be resolved as soon as you can for KR will destroy your motor over time if you let it go. It should be a quick fix at your local dealer for it might be as simple as a knock sensor or something like that...

Nick

 

Thanks guys... I am getting it checked soon.

Any other ideas on how to fix it?

Patrick :jester

 

I’m also very interested in this topic, since I have the same thing going on. I also have the same basic mods as you.

I’m unclear on how efficient the knock sensor is. It is suppose to detect the knock and retard the timing to resolve the issue, but it most likely has trouble keeping up at WOT conditions. Either way, you loose power with knocking and you don’t want to rely on the knock sensor.

The knock is caused by a lean condition, but the real question is what causes the condition. IMHO, It is most likely just bad a/f ratios in the PCM. You will need a scanner to verify this (I have one on order).

If it is bad a/f rations from the PCM at WOT, the next question becomes how to fix it. Here are some possible options.

- Higher Octane Gas (too hard to find)
- MAF translator (PCM only uses MAF at WOT to determine proper mix)
- PCM reprogramming (ls1 edit for 02 should be out in a few weeks)
- Get the PCM to learn with more aggressive driving (not sure how this works)

I’m avoiding the MAF screen removal at this point, since it could cause even more problems for the MAF sensor. The screen is supposed to help smooth out the airflow and eliminate turbulence. ZO6 does not have it, so who knows.

I’m holding off on WOT conditions at this point until I get the scanner and see what is going on.

I will repost when I get some data.

 

My 2002 with 5500 miles just did it when I had it on the dyno. Before that I really didn't notice it. The owner said it was the 91 octane California crap gas that is responsible for the pinging. The motor is stock, until this thursday! :D :cheers:

 

I've had the same problem with mine. The pinging just started after adding a gas from a Kroger gas station, it only pings when I get on it. I am hoping that it is just the gas and as soon as it is out of the system I will put a better grade in the tank.

 

Mine also has an occasional ticking at WOT/high RPM, it did it bone stock, and didn't get any worse after mods. Nothing really shows up on the dyno, and it doesn't really sound like knock or pinging, it's far too even sounding, not a normal "gravel in a tin can" sound from detonation (heard detonation/knock/pinging on plenty of other cars). Almost like the injectors start to get kinda loud. Since the dyno doesn't show any problems I've never really worried about it, and it doesn't do it all the time.

 

ttt....need some help also

 

There are PCM calibration updates for pinging :yesnod:

 

You can add me to the list on this one as well.

It showed up on my baseline, 100% stock, dyno run and again after I installed my Vortex rammer as a set of ripples and a dip in the upper rpm range. The dyno includes A/F ratio and you can see it go all to hell as the pcm tries to correct the problem by throwing more gasoline at it.

I've been told that possible solutions are:

1. Replace the stock platinum plugs with NGK TR 55 spark plugs.
2. Replace the stock plug wires.
3. Replace the stock thermostat with a 160 degree model.
4. Add Toluene to the gasoline to increase the octane rating.

I have the plugs and have also side gapped them, I just have to find the time to put them in.

I hate to replace a set of perfectly good wires that only have about 2,600 miles on them.

I'll try the thermostat next.

I've added a gallon of Toluene to a tank of 93 octane gas which will raise the overall octane rating to 94. I'll try kicking it up to 95 next. The Toluene isn't exactly cheap, so I may need to find someplace other than Sherwin Williams to buy it.

I've heard that someone took their car into a dealer's service dept to have it corrected and all they did was flash his pcm with a new program that had a less agressive spark advance curve that actually reduced his hp/tq, so I'm real hesitant to do that.

If anyone finds a solution, I'd sure like to know what it is.

Everett



[Modified by EBSDallas, 5:33 AM 4/17/2002]

 

C-5 Tech - what do the GM PCM recalibrations do? Do they adjust mixture to solve the problem or just reduce timing? If it reduces timing, I'd think we'd be better off with a MAFT or custom tuning.

Thanks,
Don