Swapping coils...

[BD]

Hey, all.

I have an 02 WRX wagon, manual. 68,000 km.

A couple of days ago, the CEL came on - solid, then blinking, then
solid. And the car was sluggish, moreso at low rpms.

I called the dealer, and had it towed, even though it was technically
driveable - the flashing CEL had me spooked.

They pulled codes 301 and 303, which (according to workshop manuals I
downloaded in PDF) mean misfire in cylinders 1 and 3.

They swapped coil 1 for 2, and 3 for 4 (I say that like I know what it
means - and I really don't). The CEL went away, but the dealer said it
could come back - the swap was partly to narrow down the problem - if
I get CEL codes 302 and 304 now, they'll replace the hardware. The
issue is not, according to them, engine-threatening, and they didn't
recommend throwing hardware at the problem right away.

Now: I admit I'm an uneducated dork when it comes to auto mechanics. I
want to understand where these coils actually are, what they do, and
why they might go bad. And what does it mean when they go bad? Is it a
'wear' issue? Something electrical? Did they have to pull the heads to
get at these things, or are they part of the ignition system?

I would have asked at the dealership, but everyone was busy and the
gal that rung me in obviously knew nothing beyond what she read on the
work order.

Again, I do have these workshop manuals, but they're more a recipe
book for fixing stuff, where I am looking to understand how it all
works.

Any suggestions of online resources?

Thanks,

BD

 

[johninKY]

Coils are those things on top of the manifold that the spark plug wire
originate from. Coils produce the spark that fire the spark plugs.
Dealer swapped positions to see if the problem moves to the other side o
the engine. If the 2 cylinders that originally didn't show a misfire cod
now show a misfire code then the problem is probably that set of coils.
But if you want to tinker yourself, replace the spark plug wires befor
anything else. Wires are cheap, coils aren't

 

[BD]

But if you want to tinker yourself, replace the spark plug wires before
anything else.  Wires are cheap, coils aren't.

Thanks. I'm not likely to tinker - I don't like to stick my hands
somewhere where I don't really know what I'm doing. That said, I would
like to understand what's going on.

Thanks!

 

[johninKY]

Suggested replacing the spark plug wires because that has a good chance o
fixing this problem. Subaru coils rarely fail. Also check the spark plu
wells for oil. Oil down there will also throw this trouble code.

 

[hippo]

Suggested replacing the spark plug wires because that has a good chanc of
fixing this problem. Subaru coils rarely fail. Also check the spar plug
wells for oil. Oil down there will also throw this trouble code.

At least OP has a workshop that believes in trying diagnostics
substitution *before* throwing the customer's money at the problem! Nic
to hear. Cheers

 

[BD]

Suggested replacing the spark plug wires because that has a good chance of
fixing this problem.  Subaru coils rarely fail.  Also check the spark plug
wells for oil.  Oil down there will also throw this trouble code.  

I think they pulled and inspected the plugs, so I'd figure they'd have
cleaned up any oil that might have been in there.

I know my oil level was a bit lower than it should have been - not
sure if that's a factor (you mention oil being where it shouldn't, so
it did come to mind)

Thanks!

 

[BD]

At least OP has a workshop that believes in trying diagnostics &
substitution *before* throwing the customer's money at the problem! Nice
to hear. Cheers

Yep, and so long as that approach doesn't impose undue risk in this
case, I'm grateful.

 

[Tony Hwang]

Hey, all.

I have an 02 WRX wagon, manual. 68,000 km.

A couple of days ago, the CEL came on - solid, then blinking, then
solid. And the car was sluggish, moreso at low rpms.

I called the dealer, and had it towed, even though it was technically
driveable - the flashing CEL had me spooked.

They pulled codes 301 and 303, which (according to workshop manuals I
downloaded in PDF) mean misfire in cylinders 1 and 3.

They swapped coil 1 for 2, and 3 for 4 (I say that like I know what it
means - and I really don't). The CEL went away, but the dealer said it
could come back - the swap was partly to narrow down the problem - if
I get CEL codes 302 and 304 now, they'll replace the hardware. The
issue is not, according to them, engine-threatening, and they didn't
recommend throwing hardware at the problem right away.

Now: I admit I'm an uneducated dork when it comes to auto mechanics. I
want to understand where these coils actually are, what they do, and
why they might go bad. And what does it mean when they go bad? Is it a
'wear' issue? Something electrical? Did they have to pull the heads to
get at these things, or are they part of the ignition system?

I would have asked at the dealership, but everyone was busy and the
gal that rung me in obviously knew nothing beyond what she read on the
work order.

Again, I do have these workshop manuals, but they're more a recipe
book for fixing stuff, where I am looking to understand how it all
works.

Any suggestions of online resources?

Thanks,

BD

Hi,
When I had that problem, it was plug wire leaking. I could see firework
in the dark. Sparks jumping all over.

 

[Chicobiker]

When my 2003 was around 100k kms, it started misfiring on one
cylinder. They put silicone grease on the contact points between the
coils and the wires, and that was the end of the problem. If your
contact points were a little bad, the action of swapping the sides
might be enough to solve your problem. At least for another few
thousand kms!