: car pings (detonation) on premium fuel?



814V
10-12-08, 06:22 PM
does anyone else seem to have this problem? i only use chevron/shell premium fuel and my car still seems to ping really bad under hard acceleration (on the track only of course :cool2:) i have not tried any octane booster or anything cause im afraid to damage something. maybe a tune?

darkman
10-12-08, 06:57 PM
It shouldn't ping even with regular (87 octane) fuel.

814V
10-12-08, 09:08 PM
mine does.. seems like its gotten worse lately.. i guess i need to make an appointment at the dealer

heavymetals
10-13-08, 12:06 AM
Maybe water in the gas.

Try changing brands for a couple of tank fuls.

Try downshifting and don't bog it in third.

814V
10-13-08, 12:18 AM
Try downshifting and don't bog it in third.

ahahhahaha thats not the problem! i tried using other brands of fuel and it seems to be even worse.

heavymetals
10-13-08, 12:26 AM
Sounds like you need to make friends with someone with EFI live....

SoJersey05V
10-13-08, 12:39 AM
sounds like the camel jockeys have been filling with crap gas!!!! probably topping off premium tanks with left over 87! they will do ANYTHING to make a buck! also i know this new 10% ethanol crap is f'ing up or landscaping equipment so i'm sure it effects us to somehow!

SoJersey05V
10-13-08, 12:39 AM
p.s. forgot to add that i haven't had that problem in the car tho...

rand49er
10-13-08, 06:48 AM
If you've got pinging or spark knock (i.e. detonation) in NA form when some of us FI'd guys don't get it, then I'd say you've got a problem.

Solution? Given the fact that you're putting 93 in the tank, I'd take it to a dealer and have them either reflash your PCM or possibly investigate another cause. Don't allow it to continue, though.

crazymikie
10-13-08, 08:29 AM
sounds like the camel jockeys have been filling with crap gas!!!! probably topping off premium tanks with left over 87! they will do ANYTHING to make a buck! also i know this new 10% ethanol crap is f'ing up or landscaping equipment so i'm sure it effects us to somehow!

Ethanol actually raises the detonation resistance of gasoline. Landscaping equipment which is carbureted suffered from alcohol because it drys out the seals doesn't work well with non-fuel injected equipment that wasn't made to hande it.

SoJersey05V
10-13-08, 10:25 AM
Ethanol actually raises the detonation resistance of gasoline. Landscaping equipment which is carbureted suffered from alcohol because it drys out the seals doesn't work well with non-fuel injected equipment that wasn't made to hande it.

good to know thank you!

814V
10-13-08, 11:46 AM
im gonna swing by the dealer on my way to work right now and i will let you know

stuckey
10-13-08, 12:45 PM
I only run Shell Premium if at all possible as a matter of fact I stopped driving the V when we ran out of premium down here. Haven't had any issues yet.

814V
10-14-08, 07:04 PM
well I spent the morning at the dealer and this is what they think. carbon buildup in the fuel system. the fix (or so they say) run my current tank out and go to CHEVRON and fill up with premium fuel and buy a bottle of "techron" and add that in as well. then "drive" the car like it was meant to be driven and bring it back when that tank is empty. I guess there goal is for me to burn the carbon out by me driving the car like I stole it?? any ideas guys? seems like if there is a problem I am only going to make it worse if I drive it hard.

PISNUOFF
10-14-08, 07:19 PM
Drive it like they told you to then bring it in on a flatbed for a new diff.

CTSV_510
10-14-08, 07:34 PM
I don't get it. We have knock sensors for a reason. If the knock sensors are sensing knock and pulling timing, and your engine is still knocking, you have more than a carbon-buildup problem in my opinion. If it's truly knock, like Randy mentioned, one possibility is a calibration issue that could be fixed with a pcm reflash.

If it's getting worse with time, I would say it's more likely a mechanical issue.

Were you able to replicate the sound for the dealer and did they agree with you?

rand49er
10-14-08, 07:44 PM
Carbon buildup can create a "hot spot" causing the fuel and air to ignite too early which is somewhat like spark knock and sort of simulates detonation.

Still, it's hard to believe it's carbon buildup. :nono: I think they owe you more than that explanation.

Tmac11
10-14-08, 08:17 PM
I'm surprised your dealer didn't offer to do an injector cleaning for you....The type you hook up to the fuel rail. Thats nuts to drive it hard with it knocking. Unless they don't mind replacing a burned piston.

a64pilot
10-14-08, 08:26 PM
Well,
it's not detonation. If it were there would be holes in your pistons by now. Pre-ignition is a possibility, but the knock sensor shouldn't allow it to occur. No, you have a problem that needs fixing. Find another dealer, yours is an idiot.

darkman
10-14-08, 08:49 PM
This might help-

http://www.streetrodstuff.com/Articles/Engine/Detonation/

rdjiv
10-14-08, 09:08 PM
i'm having a similar issue with the knocking while the engine is under a load. just happened when i filled up on thursday. what i'm hearing is almost a rattle sound and i first thought it was something loose inside the cabin. after a couple days of the symptoms (drove around this weekend), i went out and put some techron and octane boost in the tank after filling up at a different station with 91 octane. my plan is to drive on the highway until my tank is nearly empty and fill up at a reputable gas station. hopefully that will solve the problem since i haven't had any other issues and it is a fairly new vehicle.

it is true that the engine should not knock even with 87 but you also don't know the quality of fuel you are receiving. even with our sophisticated knock sensor, theres only so much crap it can take. my take for me is a bad tank of gas. although i'm not ruling anything out - i'm interested to hear how your situation resolves itself, 814V.

814V
10-14-08, 09:48 PM
well I am headed to chevron right now to get a bottle and fill up. I'll let you know

Rich H
10-14-08, 09:56 PM
I have almost an identical problem that has lasted intermittently well over a year now - pinging at WOT which I assume is detonation. It occurs only when the engine is hot and although I initially noticed it only at high outdoor ambient temps it is now occuring during the fall season. I have gone through all of the shop manual's recommended fixes. Changed the fuel filter, cleaned the MAF and used an aggressive fuel system/injector cleaner with no success. The only thing that seems to work for a short period of time is to disconnect the MAF sensor wiring (which also includes the air intake sensor) for one start cycle to allow the computer to go to a default air/fuel ratio which I assume is much richer. However, when I reconnect the MAF sensor the computer "re-learns" the old fuel/air ratio within a week and I'm back to pinging at WOT.

I'm at a loss as to why the knock sensors don't kick-in and retard the timing. I'm considering doing some testing to see if they're working but I think it's a remote possibility that both would fail. I may try to talk my dealer into a PCM reflash although my original warranty has lapsed. I did pull a plug and noticed the insulator had less carbon deposits than I would like which would indicate a lean mixture. But no damage that I can see. I would suggest you do the same.

814V
10-16-08, 04:37 PM
well guys I am shocked.. I have burned half a tank with techron added and my ping/nock/detonation is gone. I am gonna run another bottle through it on my next tank and I will let you know how it goes.

rdjiv
10-16-08, 05:56 PM
techron really does work wonders. hopefully it kicks in soon for me.