well, today i noticed that my car pings like a sonovagun ~ 3000-4000 rpms under load. i use 91 octane gas (same gas station forever) and have changed the knock sensor. checked the ecu and 0505 comes up - no problems there. can an O2 sensor go bad and not trip a code? the noise is definitely a ping and not a rattle due to something else. anyone have any comments? i know pinging is normal to a certain extent, but today it was happening everytime i got heavy on the throttle.

 

I have had the same problem. But everytime I try to get an answer on the forum, someone quotes something somebody said last time about this subject and I get know where.

 

Possibly try a good top engine cleaner to remove carbon build up in the combustion chamber.
Also might want to try a few tankfulls of 93+ octane........

 

Do you have your old KS? If so put it back in (I know its a PITA) to see if it stops pinging. If it does the new KS is probably defective. If it the new on were good the car wouldn't ping badly. It might ping a for a sec right when you step into it, but not like you are describing...

 

hmmm. i'll try the cleaner, but the new ks isn't throwing any codes, and the car pulls better that it used to with the old one, so i'm pretty sure the new one is fine. noone knows about the oxygen sensors, huh?

 

The engine uses the front O2 sensors to monitor and adjust mixture but I don't think being too rich or too lean would cause it to ping. It would run rough or miss on one or all cylinders and it would throw a code for the O2.

Maybe you just got a tank of really crappy gas. Try refilling your tank. Can't hurt...

 

I know this is something you won't want to hear, but it's normal for our car, especially in the 3000-4000 rpm range. The driver's manual states that some pinging is expected even when the car is running optimally. If you look at dyno plots, you see that the VQ motor goes thru a tansformation around then, the TQ numbers go up considerably. Some people theorize that the ECU is going thu a changeover in fuel mapping etc around that range.I guess the changeover point is a bit overwhelming for the ECU

My car does it, and I only fill up with 92 or better. It also does it especially on humid days after a heat soak situation, like after driving hard on the highway, I get off at an exit and go into a drive thru burger joint, the engine stays running all this time. Since I'm driving slowly, cooling efficiency has gone way down and the heads and everything really start to absorb some heat in the engine bay. Then I get back on the highway. With the radio off, climate control off, windows closed, and me gently pushing the throttle around the 3000-4000 rpm range on the highway, ping city. Its very quiet and I have to look for it, but it's there. It stays if I am light and steady on the throttle, until the the car reaches 4000 rpm. If I floor it any time around then, the ping dis-appears.

Try that, I'm sure you'll experience the same thing. So long as the ping is stopped by throttle movement or getting out of the 3000-4000 range, things should be OK.

DW

 

What spark plugs are you running and what is the gap set to? Plugs at the wrong heat range and/or gap would cause a ping under load.

 

i'm running fairly new NGK Platinums, at the stock gap.

 

I understand the problem with a little ping, but when the A/C is on, it's worst. Especially if I am flooring it going up a big hill. Not only does it ping, but the temprature goes up to. I have had all of my work done at the dealer. My engine is stock.

 

Have you tried a different brand of high octane gas and does it still do it then?

 

no, not yet. but i think i am going to try that.

 

I have been putting 91 Octane gas in my car since I purchased it brand new in 96. I have tried different brand of gasoline & tried octnace boost, nothing helped.