Misfire ??!!

[English Paul]

You may know I have an 08 Shelby GT500, so I'm driving it @ the weekend, (Not hammering it) stop @ some signals & hear this very loud engine noise around me , thought I had a Harley right behind me with classic mis-beat exhaust sYou may know I have an 08 Shelby GT500, so I'm driving it @ the weekend, (Not hammering it) stop @ some signals & hear this very loud engine noise around me , thought I had a Harley right behind me with classic mis-beat exhaust sound, then realize it's my vehicle & with every mis-beat I feel the car vibrate, I am in neutral so fire the engine up @ standstill, and it sounds like I am missing a cylinder or two.& already loud Bassani's sound even louder
I limp it carefully through the signal, it appears to have lost just a little power park up & get underneath looking for holed muffler or whatever (As stated many times car is my pride & joy BUT my mechanical knowledge is limited), see nothing, so look under hood for anything obvious, low fluid levels ANYTHING, nothing to see., my wife is in car & tells me she can smell something burning, I switch off ignition & let cool down for 5 minutes ( because I don't know what else to do) start it up & all of the manifestations of the problem have gone, drive home about 12 miles no problem. Take to my dealer this a:m, he does a visual on the ramp sees no muffler problem, puts it on a test that checks the last 10 starts & can find no history of misfire, after other cursory checks tells me there's nothing wrong. OK, I want to believe that but seems very odd to me, could I have sucked something into the exhaust that may have effected temporarily compression, could some dirt got into the fuel system that on turning engine off fell back out of the system, I'm clutching & straws because I don't know what I'm talking about, anyone got a clue please ??????.

[bloodyspirit058]

only thing i can really think would be make sure your spark plugs are good and your wires are good. I'm not used to those coil on plug engines, but you may find a way to test your coils and make sure everything is going good

[English Paul]

BloodySpirit:

Many thanks for response mate, dealer did say before checking over that coil might have gone duff, seemed unlikely to me @ 5000 miles, got to assume they checked plugs & connections !!??, so I will take a decko myself, as stated now running all A ok, suppose time will tell. I'm coming up to Oregon (Portland) in August & across to Seattle, love that area reminds me of home, especially the weather.

[bloodyspirit058]

are you driving the whole way or flying?

anyway, back on topic, i don't assume shops check anything, even if they tell me they check it, i double check it, i had a coil go out on a poniac once, everyone including one shop told me it was a head gasket, the first shop i was at was ready to tear the engine apart, i took it to another shop and they said it was just a ruined coil...

I'm not certain on this, but coils can fail pretty much whenever, they are built to last a long time, but with high votages and high heat, i dunno. if your wife smelled smoke or somethin burning make sure you check next time (if this or anything else happens again), there might be a wire rubbing on something, or a wire to close to something very hot causing a short :S

how long had you been driving it when this happened? like across state or just around the block ect.

[SpectorV]

my friend had no information for you

[English Paul]

Bloody Spirit

Thanks for further comment pal, I'm flying up there.

Take your point on trusting the shop, I have checked all under the hood can't see a bloody thing that might suggest a problem, gauges all reading ok in car, no burning smells, & engine running sweet & sounding healthy, beats me !!.

I had driven the car for about 12 miles when the problem came up so no real distance. The incident was on Saturday probably driven say 50 miles since then & no faults detected.

Cheers anyway mate , appreciate the help.

[CopNaStang]

Possible COP, but a bad catalytic convertor may smell like something burning, and would definitely make it run rough if something broke loose and it plugged. It may have unclogged when you turned the engine off and released the exhaust pressure.

[jommy]

everything is fine but dont move ahead before checking the parts of your vehicle...that can prove to be dangerous...