Thanks for looking. I just purchased the car yesterday, a 2001 36,000 miles with a re-ring for oil consumption. As I started my long trip back home (Corpus Christie TX to OKC), the car would ping quite badly when I accelerated hard in any gear. I filled up with 93 octane thinking it would help, but it did not. As it cooled down at night, the pinging got marginally better. I checked the codes this morning...nothing. Checked the air intake for leaks and everything looks tight and sealed properly.

The car does have a blackwing filter installed. I have my own opinions about aftermarket stuff, but could the blackwing cause the engine to run leaner than the computer can compensate for as far as AFR? Also, I would think the knock sensor would kick in to retard the timing during the most aggressive of the pinging but the manual says "don't worry, pinging is normal...", so it might be out of the knock sensors parameters. Right. I don't want the pinging to degrade to pre-ignition, and really, I'm not so sure that a car like this should ping under heavy acceleration (?)

I have read about catch cans to reduce oil vapor entering into the combustion chamber and effectively reducing the octane rating of the car...hopefully it'll help. Also, I will try to seafoam clean the engine and knock off any carbon deposits from the combustion chamber / pistons.

Anything else? Is there a way to read parameters "real-time" to see what the timing, AFR and knock sensros are doing? Is a Predator in my future to enrichen the fuel? Is it a lean running issue? So far, I'm a little disappointed, but look forward to learning...

R/
Dustin

 

Dustin,
When I bought my 2001 Coupe the original owner had just installed an aftermarket MAF on the car that pinged @ 5,500 rpm and above during wide open throttle runs. I replaced the aftermarket MAF with the stock unit and the pinging went away.

If you have the stock airbox I would try installing and see what it does.

Good Luck.

 

get it tuned out.....I run Redline S1 fuel system cleaner about every 4 tanks....as well

 

Try a de-carb first.

 

I'm not sure a decarb would work if the engine just had a fresh re-ring for oil consumption. Hopefully with the heads off and pistons out they cleaned the carbon out. My guess is lean mixture,, "see other post on MAF" 99 Nassau Blue

 

Update:
I reinstalled the stock filter box, and ran the car until it came upt to temp. It is cooler today, but it should replicate last night's conditions. 200 water temp and 220 oil temp. About 5-6 WOT runs and I did detect some pinging, although I could only really only hear it above 4000 rpm...and then just barely; but there.

I also tried some higher gear, low speed, high manifold pressure runs and it seemed to ping a little more as expected at lower rpms, but smoothed out once the rpm's caught up.

At any rate it is quite a bit better from last night, and maybe just reinstalling the the stock box fixed an unknown air leak.

The manual says not to worry...normal for accelerating or hill climbing but I just cannot remember the last performance car I drove that would ping under hard acceleration including my air-cooled 911 in VERY hot wetaher unless something was wrong.

I can't imagine all these C5's ping do they?

Any help/suggestions would be greatly appreciated.

R/
Dustin

 

Oh, also no codes shown on the DIC. Checked again after my WOT runs...still nothing.

R/
Dustin

 

Update #2,
Okay, its about the same as the day I picked it up. Hard or WOT runs will make it ping in 1st gear throughout the rev range. Higher gears will also yield some pinging, but not until higher in the rev range.

It almost seems like the advance is coming on too fast in first, and at 4500+ the car goes full advance. I tried some higher gear, low rpm, high manifold pressure testing again and the car was dead silent...not a single ping. My final thought would be to clean the MAF as it had the Blackwing installed and may have been comtaminated...

Anyone have the timing graph for a 2001?

R/
Dustin

 

Anyone care to comment on this?

1998-2002: Service Bulletin: Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set
Subject: Audible Spark Knock (Detonation), MIL Illuminated, DTC P0332 Set (Replace Rear Bank Knock Sensor and RTV Area Around Sensor)
Source: Chevrolet Dealer Technical Service Bulletin
Number: 02-06-04-023

Models: 1998-2002 Chevrolet Camaro, Corvette, 1998-2002 Pontiac Firebird
with 5.7L Engine (VIN G -- RPO LS1)

1999-2002 Chevrolet and GMC C/K Pickup and Utility Models (Avalanche, Silverado, Sierra, Tahoe, Suburban, Yukon, Yukon XL, Yukon Denali, Yukon Denali XL) with 4.8L, 5.3L or 6.0L Engine (VINs V, T, Z, N, U -- RPOs LR4, LM7, L59, LQ9, LQ4)

Condition:

Some customers may comment on a mild to severe engine ping (commonly referred to as spark knock), usually worse during acceleration and/or an illuminated MIL. Upon investigation, the technician may find DTC P0332 set.

Cause:

This condition may be the result of corrosion of the rear bank knock sensor due to water intrusion into the sensor cavity. This condition is more apparent on vehicles in which customers frequently wash the engine compartment.

Correction:

Replace the rear bank knock sensor and build a dam (wall) around the sensor using RTV to divert water away from the sensor. Use the procedure and part number listed below.

Remove the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.






Remove the wiring harness assembly from the knock sensor.






Remove the rear bank knock sensor.

Install the new rear bank knock sensor. Tighten the knock sensor to 20 N·m(15 lb ft).

Install the wiring harness assembly to the knock sensor.






Apply a bead of RTV silicone sealant approximately 9 mm (3/8 in) wide and 6 mm (1/4 in) high along the outside edge of the ridge on the engine block valley cover around the rear bank knock sensor. DO NOT form a complete circle. Leave the rear section open as shown.

From the underside of the intake manifold, completely remove the rear intake manifold seal (foam material).

Install the intake manifold. Refer to the Intake Manifold Replacement procedure in the Engine Controls sub-section of the appropriate Service Manual.

Parts Information:

Part Number
Description
Qty

10456603
Sensor, Knock
1



Warranty Information:

For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

J4437

(F-Car)
Sensor, Knock -- Replace
1.7 hrs

Add

(1998-1999 F-Car Only)
To Remove EGR
0.2 hr

J4437

(Y-Car)
Sensor, Knock -- Replace
1.6 hrs

J4437

(C/K-Truck)
Sensor, Knock -- Replace
1.5 hrs

Add

(C/K Truck Only)
With Three Piece Engine Covers
0.2 hr

Add

(All)
Diagnosis Time
0.3 hr

Add

(All)
To RTV Area Around Sensor and Remove Intake Manifold Seal
0.2 hr




GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.



© Copyright General Motors Corporation. All Rights Reserved.

 

Wow that was a great bit of info from GM. I also have a 01 and after i installed my Vararam in noticed a slight pinging at around 5500 too. I have used a intake cleaner and recently purchased a predator. I just installed the predator tune and it is still present. Now i will try to retard the timing a little and/or richen up the fuel and see if that helps. If it don’t i may replace my rear knock sensor as described above.

Let us know how your turns out!

I think im going to replace my factory plugs to see it that helps. 30k on them now and I hear the platinum "pucks" on the electrode are falling off. Perhaps if a few pucks are missing it might cause some pinging. It will also allow me to inspect the plug condition to see if its running too lean.

 

Jeep/C5,
Please keep me informed. I was looking at the Predator option as well thinking that a performance tune may provide a fatter AFR to prevent the pinging. Obviously not the case. Truthfully, I don't mind retarding the timing and/or richening things up so long as the pinging goes away. I wish I didn't have to, and I may not if this TSB pans out. If it indeed is a simple knock snesor replacement, so much the better.

Okay, since it has cooled down about 20 degress from yesterday, my evening drive tonight yielded FAR less pinging. However, I suspect as the engine got hotter, the pinging would manifest itself again, but it did make me think.

Would anyone be able to confirm my thoughts on the ignition/fuel map (I assuming its a variety of 3D mapping)...

I've really only had experience on cars that had ignition timing controlled by a dist with either mechanical, vacum or both types of advance. Basically, if the car was pinging, and the AFR was okay, then you could retard the timing a bit to stop the pinging.

Sometimes however if the intake air was too hot, it would take either more fuel (adjust the AFR) or really retarded timing, but in every case the ping could be defeated (of course power would be way down as well).

Because the corvette's ignition and fuel map are controlled by the computer, I would guess that the tables are based on a "standard day" with given parameters (?) The various sensors send info e.g. intake temp, coolant temp, throttle position, MAF voltages, crank position, cam position etc so the computer can then set the best AFR, and ignition timing etc based on what the car is telling it.

I would think though at some point the computer would not be able to adjust the ignition/fuel map to suit conditions outside the given parameters in the ignition/fuel map (tuned for both the EPA and performance, I'm assuming). Once the car experiences conditions that cause the pinging, the knock sensor would "over-ride" the ignition map to slowly retard the timing when detonation or pre-ignition occured (?) Obviously at some point, as the parameters came back into "normal" values, the knock sensor would release the timing control back to the map. I know most knock sensors can "hear" knock long before its audible by human ears in side the car.

Would anyone think that during very hot summer months, the knock sensor is constantly having to retard the timing? How aggressive is the "all in" advance on the C5?

R/
Dustin



My final thought on is that since the Corvette is a high performance car, the ignition/fuel tables are right on the very edge of detonation, coupled with a relatively high compression motor.

 

I've had a '01 Coupe since new and it also has had pinging problems that started when it had 1500 miles. I installed a 160 thermostat that helped considerably (provided I have enough forward speed to keep air moving through the radiator to keep the coolant temp under 190). I then installed a set of the Bosch Platnum +4 plugs that further reduced the problem. I also have a Blackwing, power duct, and gutted out pre-cats. These mods added power and exhaust tone but had no effect on ping. Finally I bought a Predator. With its adjustable fuel and spark settings I can keep the setup just under that which would produce pinging, and I have the fans programed to come on early to keep the coolant temp under 190 all the time. Oh yeah, and I throw in 2 cans of Techron every 3-5K miles too.

 

Changed the plugs today, NGK NR55's. The stock ones were AWFUL! I really could not believe these came out of a car with 36,000 miles...I would have guessed 150,000 miles. Actually, I'm surprised it ran at all.
I have pics if someone could host.

Result. 100% of the ping went away in first gear, and I think I might have heard some very close to the rev limit in the 2 & 3 when the water temp was below 190 degrees. As things started to get hotter (200 water, 225 oil), the problem became more pronounced, but not anything like it was before...I'd say about 90% better. In fact it ONLY does it at WOT near the upper end of the rev range...say 5000rpm+ ANything less that WOT, and the car does not ping. I am going to throw a bottle or two of techron in the car and see if I can't get the carbon to blow out a little.

I will say that I think the other part of my pining problem may be a slightly lean condition. The plugs were white and ashy on the electrodes and insulator, although the insulator (ceramic part) did have a hint of brown to it, but certainly not like a nice golden color..more like isolated spots of very light brown.

It would seem to me that the computer must adjust the AFR right at the magic 200 degree water temp (or maybe intake air related). I could almost feel it in the car as the car started to lean out a bit, followed by a very LIGHT ping.

Perhaps with a Predator, I can back the timing off a degree or two at WOT or at least fatten up the WOT AFR. From the 2 gentleman that responded with Predators, what settings are you using?

R/
Dustin

 

since there is a bulletin out on this condition, does this mean gm will do this work for free if you experience the problem?

 

My guess is not. Its simply a TSB NOT a recall item.

R/
Dustin

 

My wife's 01 had a slight ping at high rpm from the day we drove it off the showroom floor. It could be heard but did not seem alarming. After a few months I installed a K&N filter and open lid on the factory airbox and the pinging became a BIG problem. Rattled bad above 5,000rpm. Someone here on the forum suggested that the MAF was being confused by abnormal air turbulence caused by the open lid on the airbox so I returned the car back to it's stock setup with paper filter and the pinging went back down to an acceptable level. I don't know if this helps but it seemed to suggest something was messing up the MAF. Just my .02

 

For those HOT days and performance driving use TORCO. It greatly bumps octane and removed all my old pinging problems!!

jbsblown is a forum vender. If you can't find him PM me.


DH

 

My 02 had a slight ping before I started modding it and then got a custom tune on the dyno. On my stock dyno charts, the knock sensors were pulling alot of timing. Seems to be the norm, as my tuner had an 02 also and his curve looked just like mine stock, timing removed at about 4,700 RPM or so.

 

For what it's worth, my '04 began pinging after the installation of the Blackwing. The Predator, even with adjusting the timing back and richening up the mixture as far as it would allow, did not completely remove the pinging.

Last week, I finally reinstalled the factory airbox, put the factory tune back into the CPU from the Predator and voila....no more pinging.

Like I said; for what it's worth.