Random misfire code

Esteem 99 · 11-03-2009, 09:37 PM

I've been having trouble with my 1999 Esteem. It started losing power and running rough. The error code is 300 (random misfire).

I took it to Pep Boy and they replaced the plugs and wires. After this repair the car is still having the same symptoms. The mechanic at Pep Boys suggests I take it to the dealer and thinks it may be the coils.

Does anyone have anything else to suggest before I bite the bullet and take it in to the dealer.

Simon.

Ahmed Rashid · 11-04-2009, 05:49 AM

Following are possible causes for engine misfiring,

1 - Bed ignition coil.
2 - Defective spark plugs and its wire.
3 - Faulty cam sensor.
4 - Defective or clogged fuel injectors.
5 - Defective fuel pump.
6 - Defective O2 sensor.
7 - Incorrect ignition / valve timing.

solaredge · 11-05-2009, 12:12 AM

The "check engine" light started to blink going high eay speed then light went to solid-on. Rough running increased as I exited hyway and tried to make the mile to a friend's house. Although car died at stop sign, it started again with starter and was able to go for a little more, but . the last block was more run on starter motor then engine. towed to a Pep Boys, they did a code check and got #3 misfire. When the plug was pulled, there was NO central electrode in the plug's ceramic and the ground tang was totally missing!! a new set of plugs got me home, but next day no start and battery too weak to start without a jump. Buy new battery.another 50 miles = check engine light on again, and a code read will running is #3 misfire ( ` 3000 rpm, 91deg. C). Follow-up compression check on #3 is 150 psi but #4 is worse...Can missing spark plug pieces find a way into a neighbor cylinder? (The new#3 plug is found with ground tang smashed down).More new plugs and a little tranny fluid in cylinder and it seems to run home again. Next day it gets a block away, and run rough, dies, and limbs back home with more abuse of the starter...cold, it starts at high idle, runs for a few seconds then becomes rough and dies..suggestions??

Ahmed Rashid · 11-05-2009, 03:45 AM

@solaredge,get the cylinder head of ur car opened to trace out the exact problem.

solaredge · 11-05-2009, 04:49 AM

Quote:

Originally Posted by Ahmed Rashid

@solaredge,get the cylinder head of ur car opened to trace out the exact problem.

How likely is the first damaged plug a symptom ( or follow-up problem) vs the original cause? I first noted some rough running ( but not light on) after two successive fill-ups from really cheapo gas..just after the newest battery was put in, it barely even started ( therfore hard to even limp along using starter...) and a quick infusion of a couple of gallons of "high-test" gas seemed to help me make it to second garage visit...

there, a bore-a-scope showed the new damage done by scoring on top poston and walls, but still only a "430" code..

jim_naisium · 11-05-2009, 08:20 PM

You should not have scored pistons or cylinder walls, nor should you have a spark plug with a smashed down electrode, did something get dropped down the intake manifold and you hoped for the best that it would end up going out the exhaust pipe?

steemer · 11-05-2009, 09:14 PM

Quote:

Originally Posted by jim_naisium

You should not have scored pistons or cylinder walls, nor should you have a spark plug with a smashed down electrode, did something get dropped down the intake manifold and you hoped for the best that it would end up going out the exhaust pipe?

X2............

solaredge · 11-07-2009, 12:53 PM

Perhaps you missed the original post for the 2000 Esteem wagon and the first "check engine" event and tow...The #3 misfire code= a view of a nice clean plug, ceramic intact, but the central metal electrode and grounding "tang" were totally missing....

I'm guessing the pieces stayed in the cylinder abit even though I asked for assurance that no debris lingered in the cylinder before putting in the new plugs... the second new plug was the one found "crushed" ( i.e. no gap, the next day). Here, it sits again. I'll pull the coil and look at the latest plug myself, as soon as I find out which one is #3.

Helpful hints will be appreciated..

jim_naisium · 11-08-2009, 12:37 AM

Sorry, but when everything is run together in one gigantic paragraph sometimes it is hard to figure out what is old and what is new information.

But anyway, there are only three ways to crush the electrode of a spark plug while it is installed in an engine...

1 - The wrong type of spark plug was installed that is way, way, too long and the piston is physically able to hit it on its up-stroke.

2 - There is something in the cylinder that should not be there, such as a nut or other automotive part that was dropped down the intake manifold that eventually finally ended up in the cylinder. Usually this is something made out of steel which eventually gets hot enough to melt right through the aluminum alloy piston which then results in complete compression failure.

3 - The piston self destructed and ended up with a piece of itself on top of the piston head which then hit the spark plug.

Engine cylinders on four cylinder engines are usually numbered with the # 1 cylinder being furthest from the transmission (the front of the engine) and the # 4 cylinder being closest to the transmission, i.e.: 1 - 2 - 3 - 4 | Transmission.