pinging after headswap!!!

[CanadaStang]

Did the headswap on my Stang about a week ago, and it was running really great. Just went and filled up with 91 octane and now if I roll the gas on in 5th gear at 60mph I hear pinging. Kinda pingy buzzy sound. What the heck? I wonder if the gas station I filled up at, has regular in their 91 tank? I stopped on the way home and picked up 2 bottles of octane boost and just dumped it in now, I'll see if that helps. Anyone else ever have this happen? Shouldn't the computer retard the timing in a case like this to prevent the pinging? Or is there something else happening that I don't know about?

 

[CanadaStang]

I just had a thought, last night I took my Mac CAI off and put the stock intake back on, only without the snorkle. [with K&N filter] I had my air IAT hanging in the fenderwell and I put it back where it normally goes with the stock intake. Would this cause it to lean out and thus make it ping? I would have thought that the CAI would make it run leaner if anything, than the stock setup.Anyone ever have this happen? Or have any thoughts? I dumped in some octane boost, but it's still doing it.

 

[bierbelly]

Octane boost makes very little difference; might help if you put in a gallon of it. You really need to get some 93 octane in there. The old GT's don't have the 'intelligence' to pull timing like that...I think only the Cobras can. When you headswapped, you raised your compression ratio about a point. Hope you can get higher octane where you are...that's the ticket. If you can't, you might want to consider a timing adjuster that will let you back off the timing a little, but you'll lose some performance.

 

[CanadaStang]

Octane boost makes very little difference; might help if you put in a gallon of it. You really need to get some 93 octane in there. The old GT's don't have the 'intelligence' to pull timing like that...I think only the Cobras can. When you headswapped, you raised your compression ratio about a point. Hope you can get higher octane where you are...that's the ticket. If you can't, you might want to consider a timing adjuster that will let you back off the timing a little, but you'll lose some performance.

Thanks bierbelly!! The best gas we have here is 91
Seems odd why it was fine for the first 300 miles I put on it, and then suddenly this morning it's friggen pinging.Would it help if I tried resetting my computer?

 

[CanadaStang]

I tried resetting the computer. Still Pinging !!!!!!

 

[CanadaStang]

I put the snorkle back on. Still Pings!!!!!

 

[01TrueBlueCobra]

If you can't solve the gas issiue you might have to put some aftermarket pistons in to lower your compression ratio.

 

[PG98GT]

BLUF...bargain gas= pinging (for my car)
Mine pings some from time to time, especially when my wife ignores me and puts some bargain gas in it. I have to run 93 after the tune, before I could get away with 91 octane from a major gas brand. I also run one heat range hotter spark plug, which helped tame the ping too. Don't ask me why, someone suggested it and it worked for me so I'm passing it on.

 

[AquamanCHS]

Kind of a thread hijack but I recently did a PI headswap and I'm concerned about the possibility of pinging also. When I mash the throttle in low RPMs and put load on the engine I get a kind of gurgly-pop/thud noise that seems to kind of echo through my exhaust. I can feel it in my feet right through the floorpan. When I did the swap I also did VT stage I cams and BBK LT headers and x pipe and was tuned by Tim at Modular Powerhouse. I'm gonna get a few dyno pulls Monday to check my A/F and get some HP numbers.. anyone know what this could be?

Also, to the original poster, could you describe the sound yours makes a little more in-depth?

 

[TweekedGT]

I've had mine for a few months now running only 91 octane and it is fine. I guess it depends on the car. I only had about 55,000 km on the motor before I did my swap. I don't know if that would make a difference though. Weird. The only thing that might be saving me is that my Bank 1 O2 sensors are not working properly and therefore the car is running rich. The computer is shooting too much gas to my engine.

 

[CanadaStang]

Thanks for the thoughts guys.
Aquaman: It isn't real bad, but if I'm in 4th or 5th, and as soon as I slowly press the gas pedal down, it starts to rattle/ping, not a loud ping, but just enough so that I can hear it. Once the engine picks up rpm it seems to quit, at least I can't hear it anymore, but as soon as I slow down to 60ish and press the gas peddle just a bit, it returns. I had thought of going to a colder plug as someone suggested, never heard of a hotter plug making the pinging go away, but hey, if it'll work I'll try it.I'm going out of town till Thursday, but I'll try and see if I can figure something out when I get back.This is driving me crazy!!! GRRRRRR!!!!! Oh, I'd be fairly unhappy if I had to put in lower compression pistons

 

[tomustang]

seems pretty common, i get it too going up hills in 4th, whenever the engine struggles in a higher gear and the pedals down a bit.

 

[PG98GT]

Colder sparkplug

Thanks for the thoughts guys.
Aquaman: It isn't real bad, but if I'm in 4th or 5th, and as soon as I slowly press the gas pedal down, it starts to rattle/ping, not a loud ping, but just enough so that I can hear it. Once the engine picks up rpm it seems to quit, at least I can't hear it anymore, but as soon as I slow down to 60ish and press the gas peddle just a bit, it returns. I had thought of going to a colder plug as someone suggested, never heard of a hotter plug making the pinging go away, but hey, if it'll work I'll try it.I'm going out of town till Thursday, but I'll try and see if I can figure something out when I get back.This is driving me crazy!!! GRRRRRR!!!!! Oh, I'd be fairly unhappy if I had to put in lower compression pistons

Dang I messed up...I should've put one heat range COLDER on the spark plug. Should've previewed before I submitted Guess that's what I get for posting right after the kids got home from school.
I just looked at the package and they are truely one range colder. Sorry about that...hope you didn't buy the hotter plug.

 

[CanadaStang]

Dang I messed up...I should've put one heat range COLDER on the spark plug. Should've previewed before I submitted Guess that's what I get for posting right after the kids got home from school.
I just looked at the package and they are truely one range colder. Sorry about that...hope you didn't buy the hotter plug.

HAhaha, no I didn't get chance yet, I will later today. Well, I got it to stop pinging,I put the CAI back on, and hung the IAT sensor back in the fender well, and Tada, no more pinging.Not sure why that stops it though, the CAI doesn't go into the fender, so it's basicly the same as the stock intake w/o the snorkle, must have something to do with hanging the IAT sensor in the fender. Strange!! I'm still going to get the colder plugs, though., and maybe try putting the sensor back to see what happens. Kinda weird!!
Thanks for your help guys!!! Any thoughts as to why that makes it stop pinging?

 

[Ferris Bueller]

I had a persistant pinging problem on my headswapped '98 GT (Bierbellys old car , hahaha). After trying many different things to correct this, I finally checked the timing with a timing light. It seems the timing adjuster was about 5 degrees off from what the actual timing was. This meant that when the timing adjuster was set at 13*, the actual timing was 18*! So i backed off the timing adjuster to an indicated 8*, so that the actual intial timing was 13* and it pulls MUCH harder up top without any of the pinging problems as you described. I can keep the revs low in any gear and not worry about pinging

I wonder if Ford has problems with the harmonic dampner and crank sensor being off a few degrees, which would explain why some mustangs need 93 octane when stock to prevent pinging.

 

[mrvax]

I would also suggest using your stock MAF (if you aren't) and sending your EEC to Modular Powerhouse for an adaptive tune. (See my sig.) I run 93 now and have never heard it ping.

 

[CanadaStang]

I would also suggest using your stock MAF (if you aren't) and sending your EEC to Modular Powerhouse for an adaptive tune. (See my sig.) I run 93 now and have never heard it ping.

Thanks for the great advice everyone!!!
mrvax:That is an excellent idea, Thankyou!! You had advised me of this when I had some questions before I did the swap, and was planning on doing just that this winter while the Stang was enjoying it's winter slumber, but I think I'll do it right away, do to the pinging issue.
Thanks again everyone