I've been trying to figure out what to do about a ping that's been bugging the heck out of me. When the car is cold there's no ping, but once it gets hot it pings like crazy. The ping seems worse the hotter it gets here, near Sacramento, where it's been around 100 for awhile now.

Coincidentally, I put a Halltech Stinger on my car a few days ago, and I just went to Napa and got some Sea Foam in preparation for a decarbonization tonight. On the way home, I was checking out how the Stinger performs, and decided to turn my AC off, for the first time in months. And lo and behold, I could swear the ping is all but gone! Is it just me, or is that how sucky it is to have the A/C on? I could be wrong, like maybe I didn't give it enough time without the A/C to see if the ping really is gone, but I'm almost certain it's much better, so I'm thinking about holding off on the decarb for a few days.

Now I expect a LITTLE performance hit from an A/C, but not so much that engine ping is evident even at "sane" city street driving! What causes "A/C" ping and how do I elimintate it, short of sweating my a$$ off? Anybody got any ideas? Like should I run the decarb anyway? I'd sure hate to waste the time and money on the subsequent oil and filter that I understand need to follow the decarb process if it's not going to help at all.

So far, my experience with my C5 doesn't match my experience with my C4 at all. Especially for the money difference and the supposed advances in technology.

1) My C4 NEVER pinged, even with the A/C on
2) My C4 had a much nicer feeling clutch
3) My C4 had seats that kept you in position better (so you could actually take the corners without concentrating so much on trying to stay in your seat)
4) My C4 even rode nicer (probably due to "real" tires)
5) My C4 felt much more torquey (I did have a K&N, Flowmasters and Hypertech II, while my C5 has only the Stinger)
6) My C4 never gave me as many electrical problems, either.

 

My 01' vert "pinged' the whole time that I was "out West". I attributed it to the lower octane gas. Now that I'm back in Ohio getting 94 octane, it does not "ping".

 

So, are you saying that an octane booster might help?

 

That's my thoughts! In the old days, lower octane usually caused "pre-ignition" (PING). I'm stock except for Blackwing intake and Corsa indy exhaust.

 

My '01 pinged like crazy. Dealer replaced knock sensors and reflashed PCM. There was also oil in the manifold causing the problem due to the poorly designed PCV system. All this was fixed in '03/'04. No issues on my '04.

 

OK, I was wrong. Although the ping is less severe without A/C on, it's still there. Added some octane boost while I was out, topped off the tank and drove 7 miles home. No difference.

Looks like a decarb is in order, especially since BHP says his '01 also pinged like mad. I suspect the PCV run stock all this time has allowed the carbon to build up on the pistons and valves.

Although I have my doubts about the decarb working to cure the ping, at least I'll know there's nothing more I can do about it.

 

Knock sensors recently replaced, PCM flashed as well. Because you never did say whether any of that improved your '01's ping, or not, I assume it didn't?

 

How many tanks of the higher octane gas do you think it took until you were back to "normal". Maybe I need to give it more time on the boosted gas? (Doubtful, but still wondering.)

 

What octane boost did you add? Was it TORCO??
See my thread...."Got ping?Get TORCO" in the tech section.

 

No, I used something be Prestone, which had the highest "point" boost out of everything they had at AutoZone. I will do a search for your post.

 

Improved it but PCV was still a problem. The newer LS6 breather and orfice valve has fixed this problem. There is no PCV valve on the '04s.

 

My 2002 C5 also pings on hot humid days with the AC on when I accelerate at high speeds. In the winter, it never pings. After a corvette event in Jersey, the vette was pinging alot on the garden state. Turned off the AC (even though my wife thought I was crazy) and it almost went away. While pinging, there seems to be slightly less hp. I put a bottle of techron the next time I went to the gasoline station and it helped alot. In fact, I haven't heard it since. Every summer it seems, she'll ping and a bottle of techron seems to solve the problem until the next summer.
Coincidentally, my old Grand am used to ping alot with the AC on, I used to chalk it up to a weak engine not being able to handle the drivetrain load and the compressor but that doesn't make sense with an LS1. Something about the AC compressor seems to cause pinging in a vehicle that probably has light pinging to begin with but is hardly heard during normal driving.

Some people have said that LS1 edit helps alot with pinging since GM sets the timing on the LS1 to a factory default, not compensating for your particular elevation, climate and most importantly mods. I'm having a set of kooks longtube headers put in soon along with an LS1 edit dyno tune. Hopefully, I won't have any more pinging next summer (crossing my fingers).

 

Thank you SO much for relating your experience. You're the second person who suggested trying Techron additive, but I can't find it near where I live. I would think it would be easily obtainable from a Kragen or Autozone, but apparently it's not. With my luck, I'll probably have to try and see if I can pay twice as much from a Chveron dealer!

 

Ok, I checked it out and it appears I won't be able to try Torco unless I shell out $100 or so, because it comes only in quantity and is not reasily accessible without shipping. It sure would be nice if I could just by ONE to see if it cures my problem, you know what I mean? I'd sure hate to buy a case or something, then find out that it does NOT cure what ails me, or worse, turns out to be something I should NOT be adding to a C5 that's not equipped to run 100 + octane all the time.

Thoughts?

 

I had a ping problem when I first bought it. I took it to two dealers who had it in and out of the shop for 3 months trying to figure out where in the heck the ping was coming from, because I had all the knock sensors replaced, a new computer installed, running sunoco 94 and still it was pinging.

Well, I got lucky because the first dealer that gave up on it to begin with wanted it back to try again...I talked to the service manager and he assured me he would find it.

They found it, it was the starter, believe or not. The solenoid spring was weak and it allowed the starter gear to ping on the flywheel during accerleration...it sounded exactly like I was running cheap gas. That was a few years ago and to this day I have had zero pinging from my Vette.

This was a first for me and a first for the dealer. I am so glad they found it, because I was ready to sell...

 

Well if I buy a case I will gladly sell you one can. Or you could buy your own case and I or someone else will buy what you don't use!!