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code po300 help

  #1  
Old 04-30-2014, 08:40 AM
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Default code po300 help

ok saturn guru`s heres the scenario,

been getting cyl2 misfires on our 2002 1.9 dohc sc2 . tried cleaning the plug and that was always a temp solution . so i finally done a tune up .
4 new plugs and new wires .

ran great for about 9 days . this morning the wife goes out and starts it up and its running like cr*p. so i tell her leave it and take my truck .

i go out and start it just now and its running fine again . i do a pending code check and see a po300 multiple engine misfire code pending .


egr valve???
 
  #2  
Old 04-30-2014, 01:12 PM
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1) What type of plugs did you use? Non-copper plugs have been known to cause misfire issues. Get stock NGK if you can.

2) How did the old plugs look when you pulled them? Were they all oil soaked? How has plug 2 looked when you would pull it and clean it?

3) How much oil does it use per 3000 miles?

I would normally think ICM or coils at this point but if you can clean the plug as a temp solution then that wouldn't add up.

While you're at autozone or similar getting new NGKs do a loan-a-tool and get a compression tester so we can see what we are working with. It's free -- you put down a deposit, use tool, then get deposit back. Instructions for compression tests are all over the net.
 
  #3  
Old 04-30-2014, 01:22 PM
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Originally Posted by derf View Post
1) What type of plugs did you use? Non-copper plugs have been known to cause misfire issues. Get stock NGK if you can.
autolites
2) How did the old plugs look when you pulled them? Were they all oil soaked? How has plug 2 looked when you would pull it and clean it?
not oil soaked but worn
3) How much oil does it use per 3000 miles?
about a quart
I would normally think ICM or coils at this point but if you can clean the plug as a temp solution then that wouldn't add up.

While you're at autozone or similar getting new NGKs do a loan-a-tool and get a compression tester so we can see what we are working with. It's free -- you put down a deposit, use tool, then get deposit back. Instructions for compression tests are all over the net.

just ran it to the store ,when i started off it was stuttering until it reached about a grand on the tach then it would clear up .done that for a few pull outs. when i left the store it was running fine .

i suspect egr valve ,its not plugs or it would run bad all the time .raining too much to dig into it any further right now
 
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Old 04-30-2014, 03:04 PM
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during a break in the rain i took the egr valve off and cleaned it . update in a couple days
 
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Old 05-15-2014, 06:37 AM
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update

still having issues .changed plugs from autolites to ac/delco`s. no change .
so i pull the wires off at the plug ends and wipe them down and check for oil on them .
this returned the engine to normal for about 4 days .this morning (a foggy misty morning) the wife starts the car and i hear the misfires once again (pulling hair out).she leaves the car and takes the suv .

i go out an hour later and now its fine again. ran the engine and looked at the wires for any arcing and touched them to see if i could feel any voltage seeping out them ,nothing .(wires are new and bought the good oem ones at napa)

so for kicks i unplugged and replugged the control unit(big silver box behind battery)just in case its a dirty connection issue .

what to check next??

i am thinking about changing out the valve cover gasket ,but hate just throwing money at a problem and hoping it goes away .

this is a intermittent issue and i dont understand why .

could it be from a malfunctioning remote start unit??

reason i ask is this car has a remote starter,one day after i remote started the car i could not turn it off from the keyfob anymore .so i just stopped using the remote start .
 
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Old 05-20-2014, 01:46 PM
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now its running good again for a few days . one rainy morning it was acting up again .since that day its been ok .
went and ordered a new ignition control unit from ebay at half the cost of parts stores .

more on this after the part gets here .
 
  #7  
Old 05-24-2014, 08:24 AM
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A diagnostic code P0300 basically says it missfired. No real surprise, you heard the thing missfire. The 0300 said it did. What other if any codes were there?
While it may happen when the weather is clear and dry you seem to emphasize that it is misty and rainy when it happens.
And of course that can cause a problem.
If that is a problem at least one reason for it being a problem is a dirty engine leaving lots of locations were accumulated crud can collect moisture and give problems. Cleaning the engine bay is at least a partial solution that may give some benefits. The hard part is the cleaning. A high pressure hose from a car wash usually can do a good job. The negative is that it is wet thus give temporary problems until it dries off.
Derf pointed out that something other than the old fashioned (now) copper plug are the spark plug of choice for this engine. There is a reason for that and the reason in part is something like a platinum plug can actually cause a miss-fire due to the way the ignition works on the car.
You said you changed from Auto-light to AC/Delco with no change in operation. O.K., that is fine but and there is a but. Which one or both were platinum or copper. That was not answered. And as a Platinum plug CAN cause a miss-fire, if your AC/Delco's are a platinum plug, then they are a potential problem.
Derk suggested the OEM NGK for a reason. They are a copper plug.
I will agree, NGK plugs are not a mandatory brand but they are the right plug. I use Champion's myself, but they are a copper plug. I make sure of that and I am not having a problem. So the question is still valid. Are you using a Copper Plug?

"Are the spark plugs soaked with oil when you take one out to check them? If so that is a problem.
That has not been answered.

Now to be honest, changing parts may solve a problem but at the moment I do not see a reason to change a part in reading the things that have been written.

Certainly changing a valve cover gasket is a solution, but it is a solution to oil leaking all over the place causing the engine to be dirty and the car marking it's territory like a lost puppy trying to pee.

It is not a solution to a miss fire unless part of the problem is a dirty engine.

Cleaning the spark plugs solved things temporarily? Was the spark plug oil soaked? What did the plug look like? Was it half dead from age and miles? Have you checked the condition of the new ones?

Did you run a compression test?

What is the oil mileage, that question has not been answered. And are there ANY other codes when checked?
 
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Old 05-24-2014, 11:54 AM
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no compression test
valve cover does not leak bad at all .just noticed a little oil around the plugs ceramic when i pulled one ,thus oil could be leaking past the cover at the plug hole .
engine not dirty ,been pretty clean clean since i bought it .
plugs are not platinum ,i hate platinum plugs .just standard ac/delcos .

car been running good again over a week now .the ignition control unit is here but i was gonna wait until the misfire happened again and swap it right at that time to see if it goes away .
of course as soon as i bought the part it started running fine again .

old plugs were worn ,the electrode worn down .this car sees alot of road .
ngk plugs were not available when i bought plugs .
car burns a little oil ,about a quart a month .so i havent changed the oil regularly lately .
 
  #9  
Old 05-25-2014, 07:52 AM
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[QUOTE=john doe;43788]no compression test
unquote
Fair enough. The problem seems to be intermittent so a compression test might not indicate anything. But then again it might. It would be nice to know information

Quote:
valve cover does not leak bad at all .just noticed a little oil around the plugs ceramic when i pulled one ,thus oil could be leaking past the cover at the plug hole .
Unquote
To have the oil some how get into the engine,, particularly a cylinder from this source is a bit of a stretch. It probobly would have no affect on your problem.

Quote
engine not dirty ,been pretty clean clean since i bought it .
plugs are not platinum ,i hate platinum plugs .just standard ac/delcos .
Unquote'
Nothing wrong with platinum plugs. They have a place. I just changed a set on my Chrysler purchased new in 2007, 100,000 miles ago. I have seen more wear on copper plugs at 30,000 miles. And nothing wrong with those either as they too have a place. And in the case of the S series Saturn they actually perform a function due to the weird characteristic of the ignition system used.
While insistence is placed on the use of the NGK plugs because they are indeed a copper plug which satisfies the ignition, I use Champions because they are my preference and they too work well. If the two brands you used were copper I personally do not see any reason why they would cause a problem such as you are describing.

Quote:
car been running good again over a week now .the ignition control unit is here but i was gonna wait until the misfire happened again and swap it right at that time to see if it goes away .
of course as soon as i bought the part it started running fine again
Unquote:
Well? Maybe this problem did have something to do with moisture in the air. I have seen it happen. It is spooky and some what unbelievable these days with the sophistication of the electronics and packaging with todays cars. But they made the "Points Grease" or Connector Grease for a reason and that was to coat the terminals on connectors to prevent moisture from attacking the individual pin connections so it can and does happen and is preventable. Think about getting some to keep in your tool box to use when connectors are unplugged for what ever reason. I keep some handy and feel it has payed off using it.

Quote
old plugs were worn ,the electrode worn down .this car sees alot of road .
ngk plugs were not available when i bought plugs .
Unquote
I enjoy a car as a hobby and have and do own show cars. But for me a car is to be driven so I drive my show cars. It gets them dirty and wears hem out but dang, I sure enjoy driving to shows.

Quote
car burns a little oil ,about a quart a month .so i havent changed the oil regularly lately .Unquote.

One of the reasons to change the oil is to get rid of dirty engine oil. Just adding oil is not the best way to deal with that.
But most importantly is to change the filter. After about 3 to 4 thousand miles it's filtering capability is pretty much shot and it quits filtering. That is hard on the engine and does not help engine wear very much. Thanks for the information.
Crossed fingers at this point in time is about the only thing I can think of.
No engine codes and nothing other obvious to me at the moment.
 
  #10  
Old 06-12-2014, 08:30 AM
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update :

car shuddered the other day and threw a cyl 2 misfire code (nothing new) ,i read the code ,cleared it and it was fine rest of that day .
this morning ( a damp,dreary ,misty,foggy kind of morning)the car is misfiring bad enough the wife cant take it to work .
so , this is my chance . she leaves the car and i change out the ignition control module(part the coils sit on top of) with a new part i bought on ebay .
she fires right up with no misses .

only time will tell if this was the fix . if you dont hear back from me then this fixed it . if it persists i will surely update the thread . wish me luck .!
 

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