2007 Chrysler Mini Van fault code P0300?

[Whoaru99]

Ok, finding the technical definition of the code P0300 is easy - random misfires.

A bit of research seems to indicate that it can mean a problem with just about anything since the computer detects a misfire problem but not a specific cylinder or component fault.

The thing runs noticeably rough at idle and you can feel it when accelerating too. Feels doggy as well.

 

There was also a P0404 code but that didn't come back on the test drive after clearing the codes.

Anyone have experience with this that might be able to suggest a few of the more common places to look? 

[Jeremy airjer W]

Year, Make, Model, and Engine SIze for all automotive questions.......

how many miles?

 

[leech~~]

Ok, finding the technical definition of the code P0300 is easy - random misfires.

A bit of research seems to indicate that it can mean a problem with just about anything since the computer detects a misfire problem but not a specific cylinder or component fault.

The thing runs noticeably rough at idle and you can feel it when accelerating too. Feels doggy as well.

 

There was also a P0404 code but that didn't come back on the test drive after clearing the codes.

Anyone have experience with this that might be able to suggest a few of the more common places to look? 

My sons Saturn Vue sat for about two weeks in my driveway. My wife took it to the post office for a short run and we got a P0300 P0304 and P0305. This had happened every once in a while with the 3 Saturn Vues we have had. I just hook up the code reader I got at Fleet for like $69 bucks and clear them and we're good to go. Random misfires can happen when cold weather kicks in. Sadly if people just got a cheap code reader and cleared it their selves it would cost them a lot less then a $89-99 Service-light check at a dealer.

[Whoaru99]

Year, Make, Model, and Engine SIze for all automotive questions.......

how many miles?

 

2007 Chrysler Town and Country, 3.8L, ~90,000 miles.

[Whoaru99]

My sons Saturn Vue sat for about two weeks in my driveway. My wife took it to the post office for a short run and we got a P0300 P0304 and P0305. This had happened every once in a while with the 3 Saturn Vues we have had. I just hook up the code reader I got at Fleet for like $69 bucks and clear them and we're good to go. Random misfires can happen when cold weather kicks in. Sadly if people just got a cheap code reader and cleared it their selves it would cost them a lot less then a $89-99 Service-light check at a dealer.

I have an Actron 9145 scanner that reads, resets, shows freeze data and live sensor/parameter data, and had previously cleared P0404.

Previously it was just the EGR code P0404. Now it's P0300 too. P0404 code takes a little while to come back, but P0300 comes back pretty much right after it starts. Apparently the misfire is 10% or more because the Check Engine light is flashing.

When it was just the P0404 code there wasn't any noticeable driveability issue, but there sure is now with the P0300 code. It's noticeably missing/rough running both at idle and under power.

Edited November 27, 2015 by Whoaru99

[Jeremy airjer W]

A good scan tool would show you live cylinder misfires. This would be helpful narrowing down the cylinders affected. What I would do is start up the engine and then pull each spark plug wire one at a time and see if the RPM changes. If it does that cylinder is working. If it does not than that cylinder is not working. ***If you get hit by 30k V its going to tickle a bit*** Once you narrow down the cylinder(s) you can make sure there is spark and that there is no arc burn in the plug boot or on the plug. 

At 90k you are due for your 3rd set of plugs (I do believe these are standard resistor plugs due every 30k) It might not be a bad idea to start with a fresh set of Champions (please do not use anything but champions).

You can also pull the wires off from the coil pack (engine off) and see if any of the towers are corroded. You can also use an adjustable gap spark tester to make sure all of the coil towers are putting out spark.

If spark seems to be good than I have run into bad injectors on some of the 3.8 liters as well as broken rocker arm mounts that are cast into the head.

[Whoaru99]

Doesn't show any specific cylinder, which I understand would be a code like P0301 and P0303 (if, for example, if it was cylinder 1 and cylinder 3). Is that what you mean?

 

I don't know the service history, other than they typically brought it into the shop if there was anything wrong. Presumably that means maintenance had been done except for recently. The owners are elderly and the husband recently died so I'm trying to help out with it.

 

Don't like that bit about the rocker arm...seemed like there was a knock but I assumed that probably was the misfiring since it shakes pretty good.

Edited November 28, 2015 by Whoaru99

[leech~~]

 

 

What the heck why can't I delete a post that I added. Looks like issues were covered after rereading above.

Edited November 28, 2015 by leech~~

[Jeremy airjer W]

Doesn't show any specific cylinder, which I understand would be a code like P0301 and P0303 (if, for example, if it was cylinder 1 and cylinder 3). Is that what you mean?

 

 

there will be many times a P0300 will be the only code but there will be a specific cylinder showing a majority of the misfires. It's just a little easier to see that info and know where to start looking rather than pull wires one at a time.

Just had a kia yesterday. P0300, looked at misfire data and number three was the only cylinder with a misfire. Swapped the coil with number one and the misfire followed. Number 3 coil and a set of plugs fixed it.

I have occasionally also run into broken valve springs on these engines. Typically they do not like to idle at all when this happens.

Edited November 28, 2015 by Jeremy airjer W

[Whoaru99]

I'll have to check if there is a misfire history screen in my scan tool. Don't think so, but it was a quick look before Thanksgiving dinner.

Probably will end up having to bring it to a local shop anyway. It sits out in an open parking lot so doing too much isn't very practical at this point. Plus, I don't feel good about driving it to my place (~35 mi one way) in the current state.

[Whoaru99]

Misfire ended up being two plug wires chewed essentially all the way through.

Was fine for about a week now the check engine light is on again, but not flashing. Still running smoothly so at this point, without yet retrieving the codes, my guess the EGR code P0404 is back.

Edited December 18, 2015 by Whoaru99

[Whoaru99]

Turns out one of the new plug wires was chewed through again, barely two weeks after they were replaced.

I've ordered some Techflex Flexo Rodent Resistant sleeve to put over the plug wires.

Edited January 4, 2016 by Whoaru99

[Jeremy airjer W]

"rodent resistant" I like the sounds of that!!

[Whoaru99]

Indeed.

A link to the product, if that's allowed. http://www.techflex.com/prod_rrn.asp

[Whoaru99]

Hard to see much on the picture, but here's the rodent-resistant braid put in one of the plug wires. Basically looks like brown Techflex braided loom. There was a note to avoid handling with bare hands to avoid irritation. Must be impregnated with something.

 

 

[Jeremy airjer W]

Well that's neat!