sic02ss

iTrader: (4)

My car only has 28,000 miles on it, this season a couple times when slowing down in driveway to stop for garage door opening or closing the car would shake real bad and try to stall, a couple little revs worked it out and it ran fine for a while. 3 weeks ago while driving and stoping at a light it did it again and i couldnt rev it out so i drove to nearest parking lot and it seamed to go away but was missing bad, got it home and was at a loss. A buddie of mine with a scan tool told me #7 misfire so i pull the plug the looks just like the other guys plug that is having compression loss in his #7. So i bend it back clean it up and put it back in, start it up and runs fine no bickfireing or missing, drive the car about 2 miles out to our mall and home and fine, had it out sunday and driving around...fine, get on it a few times spin tires a little and get to a friends house and its backfireing and missing again, baby it home on 7 cylinders and pull the plug again, electrode bent again.

so whats up? there isnt any marks on the end like the pistion is hitting it, but it has to be right?!?! the motor isnt making any noise besides the fuel injectors and the normal ls1 tick and runs on its own just missfires on that cylinder. I dont know what it could be, bearing, rod pin, broke valve, i dont think the piston could be broke wouldnt i be hearing something?!?!

any ideas on what i should do, i cant believe with only 28,000 miles this is happeinig, im n/a with lt's, ory and all stock everything else, ngk plugs taylor wires.............HELP!

Juiced2000SS

iTrader: (1)

I had a very similar problem last year. Mine had 28k on it also. The wife was driving at the time but something happened and both the #7 and #8 electrodes got bent. The car just all of a sudden wouldn't run, backfired and all. I thought it was something she did but she only got a couple miles from the house when it happened. After fixing the plugs the car started right up and ran fine til it got warm. Then it would knock a little, quicker with the revs. I was so upset being low milage and all. We tore the whole thing down checking everything, one thing at a time. Never did find anything wrong. Gave the shortblock to LPE and they couldn't find anything wrong with that either. So I got a new shortblock, put new heads and cam in it. Never did find anything wrong. Runs great now though lol.

Also I only had LS6 intake, LT's ORY, Borla at the time.

frito1

iTrader: (12)

Mine is quiet. No noises. Just would have a miss under load with converter locked in OD. I knew I wasn't firing on one plug so pulled it. Found the bent ground strap. Guarantee something is hitting it. You better look closer for a small nick. I bet the piston or rings are coming apart. Do a compression test. It won't be good

sic02ss

iTrader: (4)

Bump for more insite

Im expecting the worst, gonna take it to my buddies house and put a scope camera through the plug hole to see if i can see anything, i really dont wanna have to pull the head but then again i dont want to tear down the motor either, just makes me sick thinking something is wrong with only 28,000 miles, so much for saving all the parts i changed and keeping the plastic under the floor mats and the stupid stuff like that in hopes that itll be worth something someday...not with a different motor it wont, i might as well driven it everyday and in the weather! sorry for ranting just a little

Juiced2000SS

iTrader: (1)

I feel ya man! Been there. You sound exactly like I did. Like I said, Lingenfelter tore my shortblock down and never found a thing. So I have no idea what hit the spark plugs. I am always curious when someone else has similar issues in hopes of them finding out what it was. Even "IF" you had to do all that I did, I think you could just rebuild your stock shortblock and it will still be numbers matching and all that stuff. I reused my block but I went ahead and got forged pistons/rods.

frito1

iTrader: (12)

You'll know more as soon as you screw the compression tester in....

Juiced2000SS

iTrader: (1)

We did that to mine after we fixed the bent plugs and compression was good on all cylinders. Oil pressure was good too.

sic02ss

iTrader: (4)

got a friend of my old mans coming over, he has a compression tester ill let you know how it reads, say a prayer for my baby

Juiced2000SS

iTrader: (1)

Cool, I hope you end up in better shape than I did. Like I said earlier my compression test came out fine. Yours could be different but who knows. Keep us posted!

sic02ss

iTrader: (4)

did a compression test, only did the one though didnt have time to do all(dont ask) read 150, is that good? Put a stethoscope on and still heard no noise in the motor at all, none what so ever, sounds they way it did when i bought it, runs/idles good. Now im really stumped. bought a new plug gonna wirl that and see if that one bends....

frito1

iTrader: (12)

I tested #3 and #5 and they were 197 and 200 respectively. However, I have milled heads and such. I'd say 150 is ok for stock. Better than nothing anyway!

sic02ss

iTrader: (4)

put that new plug in and drove the car about 2 miles, on the way home got on it hard enough to spin tires through 2nd, got it home and still idling good no misefire yet, still not 100% convinced everything is ok but i put it up for winter when its time to get it out ill deal with it then i guess, maybe pull the head off just to look and see if anything is really damaged or wrong.

sic02ss

iTrader: (4)

got an update. Ive been laid off since dec so ive been putting off getting the car out. 2 months ago i took it around the block with no insurance and it ran fine, 2weeks ago i pulled it out and turned it around to change the oil and after letting it warm up it was running a little funny. I did put a new plug in it before i parked it last year and drove it 2 miles and nothing either. so i wait for it to cool to pull the plug to see if the new one was bent, grabbed the wire to pull it off and the contact came off in the boot and stayed on the plug. the plug was not bent so put it back in. so after going to summit to get new wires i put them on friday and fired the car up and it ran better than it has in a while. I finally put insurance back on it today and probably got almost 50 miles put on today and some of those werent easy miles lol. its running fine no missing nothng, could it just have been a bad wire? seems to simple, anyway im happy to have it back on the road