mod06imprezasti

Hey guys need some help, just after Christmas I was driving from northern cali to Los Angeles and while driving all of a sudden I started to feel vibration and the engine noise changed, I pulled over and the vibration was coming from the engine it was shaking a lot. I managed to get to Los Angeles but the engine shaking continued the engine noise is still very different and it feels weak like it does not have the power it usually does. The engine light came on and I got the following codes P0301, P0302, P0303 and P0304 which apparently are piston misfire for all pistons. Any idea what could have happened?

johndabrit

iTrader: (31)

Sounds like you are not firing on all cylindars. I hope you didnt stress it on the grapevine.

Don't drive the vehicle anymore in this condition. Quick way to test.. process of elimination.

one at a time, while the engine is idling, be careful not to snap the clip and remove the wire harness connector on the coil pack one by one. Each time you pull a harness off, that cyl will stop firing and the motor will act like its going to die. Do this only for a split second as you dont want the motor to keep idling this way.If there is no change on a cyl, you know that one wasnt firing.

If you get a result from this, now its time to move on to testing whether its the coil, the injector, the plug, or the cyl which is causing the issue.

1. on the same side which you find the issue, swap the coil pack and see if the issue follows it.
2. if it doesnt, do the same with the plug.
3. if that doesn't, do the same with the injector(be careful with the o ring. Easily damaged)
4. if that doesnt reveal anything, its definitely time to go to a shop.

good luck!

strider327

iTrader: (10)

Pretty sure you coil packs are loose.

mod06imprezasti

Thanks, but i got missfire on all cylinders, shouldnt i look for something that would affect all cylinders.

johndabrit

iTrader: (31)

Yes.. BUT... you should start with the easy stuff first. You could have skipped a tooth with your timing belt like has already been suggested but checking that is a bit more intensive than checking your ignition/fuel delivery.Who knows. You could have a clogged fuel filter.

easy stuff first IMHO. Up to you though. Your car, plus the fact that i'm a computer geek and not a mechanic. What do i know?

02RS25

iTrader: (9)

this happened to me, but the car completely died. turns out it was my primary. (grey connector at coilpack) your is prob different. if it is affecting all 4 cyl, id check primary connections. yet, dont turn down what johndrabbit was stating. if u have power at primary, its either coils, spark wires, or spark plugs. but for all of them to go bad??? odd. also the fact that ur computer lists all of them in one code pull...

ODD> goodluck!

johndabrit

iTrader: (31)

Lol@ JohnDRabbit haha

mod06imprezasti

Thanks i will try all recommended options and hopefully i find out what the problem is, ill post what i find

02RS25

iTrader: (9)

fair enough. i butchered ur name LOL. my bad bro

Harry Maneuvers

iTrader: (2)

I can tell you that when this happened to me... it was because MY CRANK PULLEY BECAME LOOSE WHILE DRIVING WHICH IN TURN NOTCHED THE KEYWAY IN MY CRANK SPROCKET. The small notch in the keyway was enough to cause the crank sprocket to be off by a degree or two. This would be a very good explanation for why the engine vibration is now happening as well as the noise.

Read here.

It is worth looking into... especially if it randomly happened WHILE driving at highway speeds. Your crank pulley didnt need to come COMPLETELY off for this to happen. If you read the SL-I.net thread below... it actually happened during a long drive from Portland to Sacramento. The misfires popped up on the CEL a few hundred miles before the crank bolt backed itself completely out.

I imagine as soon as the crank bolt was loosed enough for the woodruff key to pop out of the slot on the crank pulley, it skipped out of the slot and then caught it maybe a few rotations later. You could tell this was the case because the back of my crank pulley was all chewed up from the end of the woodruff key in a perfect circle.

Put a socket and breaker on your crank bolt and see if it is completely tight. Should only take you a couple minutes.

Go towards the bottom of the first page to see what I am talking about.

Subaru Legacy International • View topic - Harmonic Balancer came off while driving. Misfires solved!!!

Post #52 is what eventually lead me to solve my issue:

http://forums.nasioc.com/forums/show...oodruff&page=3

mod06imprezasti

So I worked on my car to try and figure out what the problem is. I started with the timing belt, I removed panels in front of all timing belt pulleys and all seemed well, all the pulley marks matched. Then I reset the computer for trouble codes, started the engine and then trouble codes came back but only for cylinder #3, I unplugged the coil while engine was running and made no difference unlike other cylinders, the engine kinda wants to die. I removed the coil attached a spark plug and it did spark!! so I'm wondering what else can it be, I didn't check the fuel injector but I'm going to.

mod06imprezasti

Ok so today I swapped coil and fuel injectors and it still made no difference, cylinder #3 misfires, so it's not the coils, spark plugs, injectors or anything related to timing belt pulleys. Should I be sure it's something internal like my pistons or valves?