How to test for bad coil pack(s)?
 

Hey there,

My 2009 outlander 4wd v6) has 150,000KM on it. After sitting in the cold for a few days, if I go and start it, it creates a brutal rattling in the engine and a pretty good shudder and won't catch.

When I try it again, the CEL is on. A few more times after that it drives normal with a p0300 code (random misfire). A few driving cycles and the CEL goes off. This has happened a few times now. Mechanic says it's probably a bad coil pack. He replaced the spark plugs about 7 months ago.

Coincidentally, this started happening after I had it in for the 144,000km service. I can't imagine they did anything to cause this. They also did a recall repair (brake light swtich)

Anyway,is there an easy way to test if the coil packs are bad when you get a RANDOM misfire code and not a specific cylinder misfire?

If I need to replace them, what ones should I use? He will most likely try and get NAPA parts. Would that be ok ofr a coil pack replacement?

Thanks everyone.
Dave

manual states to remove all coils from spark plugs (so the engine does not start), for each coil...connect a new spark plug, touch the threads to a ground on the engine, and turn the engine over. You'll be watching for a weak or no spark on the spark plug. Section 16c-3 in the '07 service manual.

This sucks as this means you will have to remove the intake to check the rear coils.

an ohm meter will tell you if they're proper-****ed, but will not necessarily show hot-faults/arcing. if you don't know what spark should look like (or what it feels like), then checking them as per ccernst won't do you much good and is easy to zap yourself. i do it every now and then just for fun.

of course, the coils could be fine, and the trigger input (CPS, TPS or some other electric BS) could be the problem.

if you test 3...and one has little to no spark...deductive reasoning would suggest the one with little spark would mean that coil was bad.

Also, these coils have diodes in them and you cannot measure with an ohm meter...per the manual.
I know holding an old plug wire would give you a jolt...not sure if directly holding a modern ignition coil would give a similar jolt...haven't tried that.

why do they make vehicles ****tier as time goes on...?

WEll, the car went in today at our local mechanic (I'm 1 hour from a mitsubishi dealer).
Talking with the mechanic, he thinks it is almost certainly a coil pack.

He also replaced the spark plugs about a year ago. I know something had to be removed for him to do that. Any chance that could be causing an issue now that it is colder out?

The thing is, and this is what I don't understand, is that the truck is fine if it is driven every day or two (no matter the temperature out or level of rain, etc). It's only after the car sits for a few days (3 or 4) in the colder weather that we get this shaking and rattling in the engine that throws the p0300 code. If it was a coil pack, wouldn't it happen more often than just after it has sat for a while?
Dave

Think of it this way...I no longer have to worry about plug wires!

The only thing I can think of is if your mechanic didn't put some sort of gasket or sealant when putting the intake plenums back together. I've noticed as mine has aged, if left sitting for a while, it is REALLY noisy starting back up. It doesn't cough or sputter, but does clang around a bit.

I doubt there is a way I can tell if there is something is missing? He did that back in FEB and highly doubt he will admit not doing the job properly.

I am assuming yours only make noise when it's cold out? Meaning if you let it sit for 4 days in the summer, the noise isn't there?

Well,
Mechanic doesn't think it's a coil pack. Based on the symtpoms and when it is happening (only after sitting for 3-4 days), he is thinking it may be fuel pressure related. He says this could also throw a p0300 as not enough fuel gets to the cylinders. This would also explain why if driven daily, it's fine - the pressure isn't allowed to drop to the point of throwing a code.

He also said there was a TSB out for the outlander that a p0300 is thrown if there is too little fuel in the tank (going around turns, etc). However, mine is only after sitting.

So he says leave it with him a few days and he'll hook up a fuel pressure guage and see what happens.

Does this sound like it is on the right track? To me it makes sense...but I'm no expert.

BUMP?

CCERNST, if it was a gasket or something, wouldn't that be more of an all the time issue. My mechanic did the plugs back in February and we never had an issue until now. If there was a leak, wouldn't the cooling down at night be enough to rear it's ugly head?

I called mitsubishi and they said all I could do was bring the car there, let it site for a few days and then see if that recreates the problem. He siad if the car is running fine, there really isn't much they could check for.

Could a cause be condensation in the fuel tank if the fuel level was low? I'm just grasping at straws at this point.

Driving it daily it works fine, but let it sit for about 3 days or so, rough start and p0300, which goes away after a few driving cylces (which drive normally)

Any help is appreciated....