Forgive my ignorance, but when ever I down shift and blip the throttle, I get a single *hard ping.

Common?

Car info

Stock ( other than mufflers) 2006 C4, 26K Miles, 91 no ethanol fuel ( we can't buy 93 in Canada)

 

A hard ping? I am not sure what you are trying to describe. I have a 3.8 and don't here anything unique when rev matching.

BTW, we get 94 in Beautiful BC http://www.chevron.com/products/cana.../gasoline.aspx

 

bump

 

No pinging. I use 93 octane all the time. You may have gotten a bad batch of gas. The discount stations usually get expired premium gas and the rating will lower with age. I had it happen once and I had to top off with 100 racing fuel to burn out the tank and reset my fuel trims in the PCM.

 

I use 93 pump octane number always. I find that when cruising at about 2500 rpm and then adding more gas, I get a brief pinging. However, when cruising and lifting off the gas before adding more gas I do not get any pinging.

 

What do you mean by resetting the fuel trims in the PCM?

 

what do you mean by 'ping'? a backfire?

blipping the throttle is same as if you would not be moving at all and just did hit gas pedal. do you get something from the engine or something from gearbox?
in both situations if you get some loud noises like metal hitting another metal - check with your dealer/mechanic.

 

i blip the throttle and it pings ( detonation IMHO) ... it's a ping only 1 ping, ( athough it might be a very minor backfire) the gas is from my own gas station, so i know it's not bad fuel.
It's doneit since I got it in April. its worse when it's above 70 degrees


I am of the option that there's too much tip-in timing. but if it's a common thing I would chalk it up to operating as designed.

Due to TOS I won't disclose what I do for a living, but I have lots of experince with 600rwhp+ ( non porsche) strip and track cars including tuning

 

+1

What do you mean? and How can I do that?

 

well, try to do typical ECU reset - disconnect battery for 10min and try it again after that, if you still get detonation at innocent throttle blip with clutch pressed in - check with PIWIS (dealer or pro shop) if engine throws any codes.

 

My 2005 C4 does the same thing , some times with a blip or the odd time
under acceleration ( the car is new to me , so not sure if this normal)

 

Maybe it has something to do with the living in the peg!

All joking aside, two problems, both from Winnipeg, perhaps there is a bad batch of gas. I know fordguy says it is from his station, but perhaps there was a refining problem, or a transportation truck had some contamination. It seems odd to everyone else that has commented.

 

to rule out gas - IF after ECU reset it still backfires in same way - throw in a bottle or 2 of octane booster into your gas tank (or pour in plenty of 100 octane race fuel) and try it again - if it does detonate and revving feels same way.