Misfiring... Again!

[iredremix]

So a couple of weeks ago, I was driving about 25 MPH in 2nd gear. As soon as I go up to about 45, I shifted to 3rd and the car kinda stuttered. I had this problem before. The car would actually jerk at times while driving. I got a CEL, checked out at autozone and they said it was P0300... RANDOM MISFIRE. the guy said it was probably my coil packs, but can also be my spark plugs, which is easier to fix and cheaper.. anyway.. i changed the spark plugs and the problem went away.. i was a happy camper cuz i fixed my car without having to take it to my mechanic.. 2 days later, problem came back and the car started jerking or stuttering randomly... sometimes even in reverse..

anyone know or having this problem? it happened to me before and according to my dealer, they changed my O2 sensor.. if it is the coil packs, it's gonna be a PITA because they're so damn expensive and hard to replace. any ideas? anything is appreciated.. my car has about 48000 and is a daily driver. no major mods

 

[8.5MS3]

sounds like the coilpacks. since your unmodded I would bring it to the dealer. your still within the 5yr/60k powertrain warranty. Do you have the stock plugs or colder ones? I have the ITV22s and they are a bit shorter than the stock ones. Some people stretch the spring inside the pack to make a better connection

also check the gapping on the plugs. 0.030" is what you want. any more and you will misfire

 

[iredremix]

hmm. changed them to bosch spark plugs.. and i kept them on. the guy told me i didn't have to gap them.. is this true? if i bring it to the dealer, will they charge me to find out what the problem is? i have a CPE CAI. that's about it.

 

[8.5MS3]

NEVER trust the "pregapped" guarentee. I ordered my Denzos and they were all over the place. You need to bring it to the dealer with the CEL lit. I wouldnt drive around waiting for that to happen tho. can cause a lot of damage. Also the misfire code only shows up after 3 events have been detected....thats a lot of potential damage

 

[iredremix]

damn. u think i should put the stock plugs back? do u know if they charge you to take a look at it and tell you the problem?

 

[8.5MS3]

no they shouldnt charge you since it would be covered under warranty. how do the stock plugs look? compare them to this:

http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm

http://www.gnttype.org/techarea/engine/plugs.html

 

[iredremix]

hmmm, if i remember correctly it looks dry and dark. right now, im getting about 15 MPG only. are u positive it will be under the 60K warranty? you know those stealerships...

 

[8.5MS3]

your engine is misfiring.....powertrain warranty includes engine tranny & drivetrain, excluding wearing items(clutch). the engine is broke...they gotta fix it. if you had 60,001 miles then they could charge you.

put the stock plugs back in, take off the intake (they can bs you and claim the intake leaned out the afrs and ****** up whatevers wrong) dont give them any room to pass the blame to you

 

[iredremix]

alright cool im gonna take off the CAI then. also the BPV has this tube that connects to it.. when u take off the tube, theres a little stub that goes into the tube.. it broke, but i know that's not causing the misfire cuz it broke after the CEL. maybe i should buy a used one and just wait until i install the new one so that they don't give me problems. I guess i'll take some time tomorrow and put the plugs back on.

 

[8.5MS3]

i would show them that. tell them i got this code and the tech showed me my bpv broke. make them fix it.

Also why dont you hang out at the weekly Mazdaspeed meets on thursdays at Douglaston Plaza?

 

[iredremix]

yea i broke the BPV stub by accident.. it was my fault.. im gonna see what i could do. do u know any tech guys in any of the mazda stealerships?

yeaaa ive been tryin to go to the damn meets for the past few weeks but i had to work and the last 2 weeks, couldn't drive my car =/

 

[8.5MS3]

nah not really. If you came to one of our meets you could probably buy a stock valve off of one of the guys for real cheap...

 

[iredremix]

got a guy who will sell me for 30 bucks.. think its fair? just don't wanna have problems with the dealer.. they're assholes.. the mazda in hempstead are pretty ok..

oh s*** BTW last december, my engine mount broke and engine dropped. forgot to tell you that they red flagged my car after fixing it cuz of the intake.. according to my friend, CAI would never cause a misfire, and if for some reason they think it's that, they would have to prove it. i should just bring it in with the CAI right?

 

[8.5MS3]

ive gone to my dealership with all my mods, never gave me a problem...but the issues ive gone thru have nothing to do with the engine so i dunno.

Everyone knows an intake wont cause a misfire, but 95% of the techs dont know their ass from their elbow so i would take it off anyways. 15 min could save you X amount + labor if they wanna be dicks

30 bucks sounds fair

 

[iredremix]

alright so i'll just take it off i guess. if they ask, ill just take them i took it off right away when they gave me my car back. i might bring this in sometime next week or the weekend. i gotta fix my 97 camry which needs a water pump and timing belt replacement.. another PITA

 

[drzcrazychulo4u]

hey wassup guys just noticed you guys live in queens and i had the same prob then i thought it was ok and guyss what i blew a rod or piston so get it checked. also i read you guys chill on thursday?? let me know about that i need some help fixing my car so it would be nice if someone who knows about our ms3 to help me fix this. my car is flagged so i will buy upgraded pistons and rods. if you guys know anyone i will fix in my garage.

 

[8.5MS3]

where in queens are you from? your profile thing says florida.

a misfire is just another word for detonation so im not suprised you blew. i would park the thing the instant it happened n tow it to the dealer.

what do you want to do in your garage exactly? build the motor? have you sent it out for machining yet? got all the required tools? lift etc?

 

[drzcrazychulo4u]

i live in college point. my car is in my garage parked . i want to open it up and see really wats wrong. take off the head. i havent sent it out to a machine shop yet cuz i wanna see what is really wrong and tools i can get. just 1 thing i dont gatta lift.

 

[8.5MS3]

do you have tools? the MS3 shop Manual? is there a hole in the block? how did you blow?

 

[drzcrazychulo4u]

i have most tools let me know what you need my boy goes to Lincoln tech and we could get tools from there. i dont have the ms3 shop manual but i could get it and no hole in the block. the car turns on it just sounds like it has cams. there is a misfire in cylinder 3 so i took it to lincoln tech and they put a camera in cylinder 3 and saw that there were metal shaving in it.

here is a video of the sound
http://www.youtube.com/watch?v=Q5BgcnzVEVk