I was in Vegas just this last November. I got gas at a station on the South West side of town (West of I 15) which I believe WAS a Chevron and they had 92 octane gas there with that Techron stuff in it that everyone seems to rave over.

Seriously though, if a dyno tune is not in your immediate future (or pocketbook), I'd strongly suggest re-installing the factory airbox, and forget about randomly swapping out parts like sparkplugs, plug wires and fuel filters, and looking for loose nuts and bolts on the exhaust system.

Personally, I can't imagine forking out 7 or more bucks for ANY kind of additive in a can as a cure-all for pre-ignition. If the price-per-gallon you were paying at the pump was $2.50/gal, adding a can of that stuff would be the same as actually paying $2.88/gal.

Fix the problem....don't simply put a band-aid on it.

Hey, it's only money, right?

 

Bring it over to my dealership and I'll throw it on the scanner for free. This will tell you EXACTLY what is wrong with it..

PM me and we'll hook up..

Jeff

 

Jeff, you're a good guy.
If you two discover a problem via the scanner, could you please report that back to the forum. My '04 with GHL catback and Z06 airbox cover has exhibited an ongoing tendency to ping, sometimes fairly badly. My dealer told me that my car's level of pinging is "normal" -- I don't think so. I used a Predator to retard WOT timing by a few degrees and that fixed the problem. I still think, however, that the PCM and associated sensors should prevent audible pinging without my making adjustments to the timing (even with California's 91 octane fuel). I would appreciate any information you can share about Robert's car.
Thanks, Ernie

 

Not that I know much, but what I do know is that after 35K miles on my car the stock plugs were SHOT! I only had 3 of the platinum "pucks" left on them (hopefully the other five went out the exhaust ports) and there was very little of the tips left. Finally the gap was HUGE...actually, I was surprised the car ran at all! So, IMHO the stockers can *easily* be beat.

I'm not sure why there seems to be this blind loyalty to the stock plugs. I'm even more confused by the guys that suggest that people leave them in for the advertised 100K miles! I mean, some folks will suggest everything under the sun to eliminate the dreaded "ping" and yet not suggest a quick and easy plug change...!? I try and keep stuff stock when I can because I do know that the engineers that design cars are pretty smart guys, but when accountants and vendors deliver a sub-par product its time to "call a spade a spade".

Anyway slapped in some NGK TR-55s and replaced the Blackwing with the stock element eliminated 97% of my ping. Although it will *still* ping on a hot day with high throttle settings and low manifold pressure, it would be expected from almost any engine. However, I suspect the car could also use a top end cleaning as well.

Good luck!

R/
Dustin

 

I'm currently testing small amounts of acetone for better mileage, I have no pinging problem even with 2 degrees more advance than stock. In my research I have found that acetone will improve octane along reducing vapor pressure which is how it gets better mileage. I'm only using 6oz per full tank, I'm sure a larger concentration might clear up your pinging problem, I would also add some Berryman B-12 to your gas, it will clean the injectors and upper cylinders and fuel tank sending unit contacts. In quantity acetone is relatively cheap at about $12 gallon. Its quite possible that Berrymans contains some also.Do not spill either on your paint as it will blister in nothing flat.Don't sniff it either.FWIW I'm getting about 1.2 more mpg in city driving in limited[350mi]driving.And I'm not babying it, if anything I'm driving it harder with many spirited 0-60 runs...

 

I have a 2001 Z06 which is completely stock with the exception of a Vortex airbox/filter setup. It normally gets 93 octane premium, and ping is not a problem. Summer before last I took an extended road trip and as soon as I hit the 91 octane premium in West Texas it started pinging under load and it pinged through NM, AX, CA, NV, UT, CO, and NM again until it got back to 93 octane land in Dallas. It was checked out by a dealer in Grand Junction Colorado (my nickel) and again in Houston. The Houston dealer insisted on doing a top engine cleaner twice before he gave up and said my car is normal. My ECS was reflashed twice with the latest codes, to no avail.

I have a buddy that used his 2003 Z06 for at least two years on the California crapgas, and he claims no audible pinging, so what gives?

 

I tried this myself today with my '04 Coupe. I have the factory tune installed and the timing bumped +3% with the Predator. I get some pinging with the Blackwing installed. I put the stock box with the paper filter back in and had no ping what so ever. I put the K&N in the stock box and had one instance of slight pinging. I'm going to run the K&N for awhile and see if it stabilizes.

BTW, ....all of this is on 93 Octane Mobil/Exxon gas.

 

 

I reinstalled my stock airbox last night and did exactly what was suggested and already used some duct tape to close off the larger hole. I, too, am thinking there is to much turbulance getting to the maf, especialliy with the fog light housings cut open. We will see when I go to work. I'll let you guys know!!

Thanks!

 

My 02Z also used to occasionally knock under full throttle when it was hot outside. I then started using 92 octane fuel and it no longer knocks. All it took was 1 octane point to eliminate the knock.

 

OK, here it is! Like I said, I put on the factory air box with the lid cut way open. I used some tape to close the hole a little, but it is still pretty large. The next day I drove to work and the ping was still there but not as bad. There is alot of traffic here in Vegas and there's not a whole lot of oppertunity to rip down the road. This mornig I changed my oil ( back to M1 from R Purple ) and the pinging pretty much went away!! There is an initial knock at first but then the engine stabalizes and rips!! which is where I was when things were basicly OK. Pretty wild! I know some oil does get into the cylinders via some ring flutter, but this is crazy! Anyway I ordered a Z06 air box lid and I'm leaving the K&N in and all should be good. I want to hear some opinions on this!

 

Shop owner friend of mine swears by Royal Purple, but then again he builds race cars, latest is a ChevyII with 2200 hp[estimated,dyno broke at 1700] of single turbo powered 383ci LT1.I still think cleaning the inlet tract with Berryman or even Seafoaming it will help eliminate your pinging. There used to be a Sunoco just off 95 near Cheyenne that had 100 octane.

 

Glad to hear things are improving! It will take some mileage for your pcm to adjust completely to the change in airflow and even if you go all the way back to the paper element and stick with 93 octane you may still hear slight ping under WOT.

You said you want some opinions on this. I will go way out on a limb and give you a great big WAG. Please help me out if I have any wrong info and give the correct info.

If I remember correctly all 01 LS1 engines received the LS6 intake manifold but did they also get the larger MAF from the Z06? If they did get both of these larger (more airflow) components and GM did not invest enough effort into re-calibrating the pcm to handle the increase could this be a key to this problem? Then we add more airflow with aftermarket filters increasing the airflow beyond the pcm's ability to correct the ping?

WAG #2 would be turbulence in the maf created by the removal of factory airbox.

 

Check your bellows to the throttle body. I've seen a couple that have been leaking air past it because of an overtightened hose clamp. Both of the ones that I've seen were with blackwings. You can try spraying carb cleaner around all of the clamps when your car is idling and see if the rpm changes. If it does change then you have a leak. There is also a bulletin out for a spark knock on many c-5's because of a corroded knock sensor. It is common on these because we wash our cars more than most and water puddles up around the rear knock sensor and it will give a false reading. Your local dealership can pull it up for you.

 

I think you have the same problem I had. What temp is your car running?

I doscovered that whenever my temps got near 200 (coolant), which is easy to do with a stock thermostat, my car would ping. Tried everything I could think of, including changing gas, fuel filter, decarbonizing the pistons, etc. Nothing worked. Set up an appointment at a tuner, hoping to kill 2 birds by lowering the fans-on temps, and get a little more power with the tune at the same time.

Before going to the tuner, I swapped out my T-stat to a Hypertech 160. On the way to the tuner, I noticed that car ran 178 degrees tops, and it didn't ping once. Had it tuned anyway, because I still needed the fans-on temps lowered. Not been a problem since. And, now, instead of 16mpg, I'm getting 23 all around. MN6.

 

Get the latest PCM flash from the dealer before you try anything else (the one that inlcudes the column lock thing for MN6s).

Part of it addresses the pinging.

 

I have an after market bellows and air bridge, which is more sturdy. I went through crushing the stock airbridge already . Also my car is running pretty cool, unless idleing for a time. When the knock was bad, the temp was cool - 195 or so.

How do I go about this PCM flashing? Is this some sort of recall?

Thanks!!

 

That's exaactly what I was talking about. Temps near 200.

Apparently, something's up with the stock tuning on these cars. Maybe it only affects sh|tty gas states like CA and NV, or something.

I run a Halltech Stinger, but had the ping with my stock intake, as well. It was really bad on hot days. When the car temps were under 180, it didn't ping. When they got up toward 200 the ping was so bad the car could barely get going from a stop when going uphill.

Unfortunately, with stock programming and stock t-stats, you can only run the optimal 175-180 temps when the car is relatively cold. And, I noticed that at those moments after the car was warmed up, I could get on it, and I had no ping.

Changing the thermostat alone solved the problem, but if you don't lower fan temps (which you need to to with a program tune), the car will only maintain the lower temps while moving at near highway speeds or better, because the stock fans come on too late, which means when there's not enough air flowing by the radiator at low speeds and town trafffic, and the car will get back to near 200 again, and the ping will return.

It's up to you to do do what you want, but I feel sorry for you, because I went through all the thingg you're going through, and I thought sharing my sexperience with you might give you some insight as to what may be going on.

If the dealer is going to charge you for the latest factory flash, I would put that money toward a handheld programmer, or a professional tune instead, and change the t-stat, because temps play a BIG role with pinging, and the factory flash will not adjust fan temps, so you would probably be wasting your time.

 

After reading all the articles on the C5 in all the magezines, everyone said it was a phenominal vehicle right out of the box. I really think that getting this vehicle back to basicly stock form ( mainly air intake ) should do the trick. I appreciate all the advice from everyone, but I don't feel I should have to do all sorts of modifications just to get this car to run properly. As far as I remember, my car ran good when I purchased it, without a pinging problem. I am going to do what I can and see how it goes. If all my efforts fall short, I was offered, by someone on this forum, a free diagnosis at his dealership. I will persue that avenue and see what results I get. I'll keep you guys informed!

Thanks again!!