Car Troubles..HELP
Car Troubles..HELP 1999 Z28 M6 105,000 miles
alright, well ever since i raced this WRX (win by the way)and went slightly into the slashed area (normal and red) of the tach but def. not into the all red zone (didnt hit rev limiter), i have heard a little ticking sound coming from the engine. when i rev it, it goes faster and when i idle, it keeps a steady pace. so i went over to a friends house who are good with these cars and they said it was rod knock, which i think i understandable, i thought i needed to lube my belt, hahaha.
so while picking up my window motors and rear end fluid and stuff, i gave them my license and got the code scanner, it gave me p0300 or p 300, which they said is individual or multiple cylinder misifre.
my question is, how can i know which one it really is, hoping its not both? from your personal experience, which one do you think it is? could i have broken a coil pack or sumn, i have checked my plugs by the way, which are tr55s with msd wires if that helps. also, if it is rod knock, does that mean its time for a cam?
please, any help is appreciated and also let me know how i did on the car info and symptoms, etc. im only a month into the car.
ps: could i hurt anything by driving like this?
pps: if i do get on it which is only to maybe 3k rpms, everything feels there, doesnt feel like a cylinder is shut down and i have riden in a car with a cylinder down at WOT, if that means flooring it, a plug wire wasnt on all the way.
ppps: if it is time for a cam, wat would you guys recommend for me, what is good for texas daily driving, im reading that FM13 is awesome. also what should i do for surrounding valvetrain?
thanks again dudes.
alright, well ever since i raced this WRX (win by the way)and went slightly into the slashed area (normal and red) of the tach but def. not into the all red zone (didnt hit rev limiter), i have heard a little ticking sound coming from the engine. when i rev it, it goes faster and when i idle, it keeps a steady pace. so i went over to a friends house who are good with these cars and they said it was rod knock, which i think i understandable, i thought i needed to lube my belt, hahaha.
so while picking up my window motors and rear end fluid and stuff, i gave them my license and got the code scanner, it gave me p0300 or p 300, which they said is individual or multiple cylinder misifre.
my question is, how can i know which one it really is, hoping its not both? from your personal experience, which one do you think it is? could i have broken a coil pack or sumn, i have checked my plugs by the way, which are tr55s with msd wires if that helps. also, if it is rod knock, does that mean its time for a cam?
please, any help is appreciated and also let me know how i did on the car info and symptoms, etc. im only a month into the car.ps: could i hurt anything by driving like this?
pps: if i do get on it which is only to maybe 3k rpms, everything feels there, doesnt feel like a cylinder is shut down and i have riden in a car with a cylinder down at WOT, if that means flooring it, a plug wire wasnt on all the way.
ppps: if it is time for a cam, wat would you guys recommend for me, what is good for texas daily driving, im reading that FM13 is awesome. also what should i do for surrounding valvetrain?
thanks again dudes.
Last edited by jdoyle; Apr 18, 2005 at 08:28 PM.
heh.. i have the same problem.. i am acutally taking the engine apart tomorrow to look for it.... but if the scanner says misfire... then that probably would be it... but MY guess is that a valve might be out of place or loose and could intern cause misfire?... eh... just my .02
Originally Posted by Saad06
heh.. i have the same problem.. i am acutally taking the engine apart tomorrow to look for it.... but if the scanner says misfire... then that probably would be it... but MY guess is that a valve might be out of place or loose and could intern cause misfire?... eh... just my .02
my SES comes on every now and then and then goes off a little later, car doesnt run or sound any different, so i kinda disregard it.
but thank you very much for your input.
I would try posting this in the internal engine section as they could probably help you narrow down your problem. My guess would be either rod knock or a valvetrain tap. If it is a rod knock, it is basically time for a rebuild. If it is a valvetrain tap, it could be something simple and easy to replace. As for the code, it could hear the mechanical noise and think it is a misfire. If you wanted to narrow it down, try a mechanics stethoscope and see if you can figure out where exactly your noise is coming from.
Hope this helps.
Hope this helps.
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Joined: Dec 2001
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From: Cypress, TX
Same thing happened to me in my Trans Am. Sounds like bent pushrods. They're easy to check. Just pull the coil packs, valve covers, and the rocker arms. I bent a grand total of four of them once.
My recommendation would be to not drive it until you check it out since doing so could cause additional damage.
My recommendation would be to not drive it until you check it out since doing so could cause additional damage.
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From: Cypress, TX
Originally Posted by 00 Z-28
Bent pushrod?
The erratic idling and what-not would be caused by the valves not opening up all the way on the cylinders that are effected. A distinct "ticking" sound is heard because of the gaps between the lifters and the rods and between the rod and the rocker - the overall length of the bent pushrods would be shorter now.
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Originally Posted by CySevans
Yes. Do you not know what a pushrod is?
The erratic idling and what-not would be caused by the valves not opening up all the way on the cylinders that are effected. A distinct "ticking" sound is heard because of the gaps between the lifters and the rods and between the rod and the rocker - the overall length of the bent pushrods would be shorter now.
The erratic idling and what-not would be caused by the valves not opening up all the way on the cylinders that are effected. A distinct "ticking" sound is heard because of the gaps between the lifters and the rods and between the rod and the rocker - the overall length of the bent pushrods would be shorter now.
But at the same time it could be ignition related. All these checks are easy, but starting from the outside in would be the way to go! 
Originally Posted by txhorns281
unless your exhaust is just too loud then you're just left with that crappy idle stuff... But at the same time it could be ignition related. All these checks are easy, but starting from the outside in would be the way to go!
But at the same time it could be ignition related. All these checks are easy, but starting from the outside in would be the way to go! also when this first started making noise, there was no SES, it was one for like a day then turned off, now no SES. how long would this procedure take, cuz im booked everyday from 7-6? also my idle seems normal, no low or high, idles at like 800-1000 depending on temp. maybe sometimes a little but nothing outrageous
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Joined: Dec 2004
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From: Beaumont, TX
Originally Posted by jdoyle
are pushrods expensive, can you buy them one at a time?
Last edited by ACW; Apr 25, 2005 at 10:27 PM.
Originally Posted by ACW
Hardened pushrods are available (which are more expensive), but you'd probably want to just get a replacement stock one if you don't have a lot of engine upgrades. New from a GM parts dealer they'd probably only come in an pack of 8, but it was suggested in this thread that you might be able to get a single one from a sponsor who has the stock ones left over after upgrading them on customers' cars.
Originally Posted by jdoyle
i just have a flowmaster 2 chamber but with the car on and the doors shut you cant hear it at all. i have to actually put my head under the hood to hear it, so i guess its just bent a little bit, are pushrods expensive, can you buy them one at a time?
also when this first started making noise, there was no SES, it was one for like a day then turned off, now no SES. how long would this procedure take, cuz im booked everyday from 7-6? also my idle seems normal, no low or high, idles at like 800-1000 depending on temp. maybe sometimes a little but nothing outrageous
also when this first started making noise, there was no SES, it was one for like a day then turned off, now no SES. how long would this procedure take, cuz im booked everyday from 7-6? also my idle seems normal, no low or high, idles at like 800-1000 depending on temp. maybe sometimes a little but nothing outrageous
Originally Posted by ACW
Hardened pushrods are available (which are more expensive), but you'd probably want to just get a replacement stock one if you don't have a lot of engine upgrades. New from a GM parts dealer they'd probably only come in an pack of 8, but it was suggested in this thread that you might be able to get a single one from a sponsor who has the stock ones left over after upgrading them on customers' cars.
Last edited by 99BLACKBIRD; Apr 20, 2005 at 12:57 AM.
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Joined: Dec 2004
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From: Beaumont, TX
Originally Posted by 99BLACKBIRD
Shouldn't he go ahead and replace them all? I don't know for sure, but if one bends, I would want all knew ones, just so I wouldn't have to change another bent one in the near future.
Last edited by ACW; Apr 25, 2005 at 10:28 PM.
Originally Posted by ACW
Good point, but since it sounded like he was concerned about the expense, the others don't really need to be done now... :shrug: Another option would be to get the set of 8 but hold the rest in reserve for future replacements
Originally Posted by jdoyle
well i did pick up one last night, but what i was thinking, if i have a bent pushrod, i might as welll just get a cam and supporting valvetrain, whatdo you guys think?
Have you eliminated the ignition yet? That's the easiest place to start (once you know where your misfires are happening). Before you go diving into the motor, try some easier things. Don't be the someone who ran out of gas or something and replaced the whole fuel system instead of obviously filling up.
Originally Posted by txhorns281
I think your misfires could or could not be related to valvetrain, and you still have no clue which or how many cylinders are the culprit. And should it be a pushrod, turning a pushrod fix into a cam install is like turning a 15 min job into a half day job. Up to you if you have the money
Have you eliminated the ignition yet? That's the easiest place to start (once you know where your misfires are happening). Before you go diving into the motor, try some easier things. Don't be the someone who ran out of gas or something and replaced the whole fuel system instead of obviously filling up.
Have you eliminated the ignition yet? That's the easiest place to start (once you know where your misfires are happening). Before you go diving into the motor, try some easier things. Don't be the someone who ran out of gas or something and replaced the whole fuel system instead of obviously filling up.
Originally Posted by jdoyle
how would i go about checking the ignition and stuff, car always starts up fine hot or cold with absolutely no problems, but i guess that is in the starter department, no sputtering or surging or anything while driving or idling, to me, it drives as fine as it did the day i bought on 3/15/05, lemme know plz thanks alot
After that, then you can start looking mechanically. Since you said the car drives well and you don't feel any stumbling, I'm led to believe it's ignition related. There's always the possibility of a goofy O2 also causing disruptive fueling as well. I think you owe it to the car (if you care about it) to be thorough. At 100K these cars do let go of a few things, surprise surprise though considering how hard most of em are driven.
Originally Posted by txhorns281
Ok well the P0300 misifre code on a stock motor (or really any motor, but especially on stock) means something. The fact the you get it intermittently doesn't suggest a pushrod IMO since if you did have a well bent pushrod, you'd have more frequent misfires. Either way, it's helpful to isolate the misfire(s) to their particular cylinders that way you can swap out plugs/wires/injectors/coil packs on each cylinder to see what is the cause. If none of those, then the ignition system can be scratched off the list. When's the last time you did plugs and whatnot?
After that, then you can start looking mechanically. Since you said the car drives well and you don't feel any stumbling, I'm led to believe it's ignition related. There's always the possibility of a goofy O2 also causing disruptive fueling as well. I think you owe it to the car (if you care about it) to be thorough. At 100K these cars do let go of a few things, surprise surprise though considering how hard most of em are driven.
After that, then you can start looking mechanically. Since you said the car drives well and you don't feel any stumbling, I'm led to believe it's ignition related. There's always the possibility of a goofy O2 also causing disruptive fueling as well. I think you owe it to the car (if you care about it) to be thorough. At 100K these cars do let go of a few things, surprise surprise though considering how hard most of em are driven.
also, wouldnt i hear something if a piston wasnt firing, or be able to tell if the firing order was out of whack cuz it just sounds wrong? isnt there also an 02 sensor code, or would this be why you said a goofy 02, the car isnt picking up that is bad, but causing surrounding areas to become the center of attention instead?
oh ya, thanks for all the help