I have an '03. Repeadly my front (#1 and #2) coils fail and cause a misfire. I've tried swapping coils from other cylinders and replacing them with both Denso and NGK brand coils. Some times they last a year, some times it's two weeks. I've replaced the spark plugs several times. No oil in the plug wells. Harness looks fine.

Any thoughts?

 

A little more detail would help. Or even a lot more detail.

 

When a coil fails, if you move it to another position, presumably the failure moves with the coil, so they are being permanently damaged by whatever is going on?

 

I'm happy to add detail. But was hoping to find someone who might have had a similar experience.

I bought the car with about 40k on it. At about 55k one of the front coil failed. So I replaced all eight with Delphi coils and Bosch plugs. Those kept failing (always a front). I always replaced the plug when I replaced the coil. I tried moving the failed coil around, but it was the coil that had failed (the failure moved with the coil and an new coil always fixed it). It got to the point where I had all of the spare good OEM coils in the trunk as well as a tool kit with everything I needed to compelte a quick coil swap. I forget how many failed. Maybe 3 or 4. At some point I started buying new NGK coils to keep as spares. My experience is that the OEM, Delphi, and NGK all fail about the same.

Fast forward to now (about 2 years later and now at 90k) and it just threw a code for both front coils (it's worth mentioning that I just replaced the water pump. But it's hard to imagine that's related. It was an easy job that went without issue. I guess, now that I'm typing this, it's possible that some water got into a connector (but I will say, that seems unlikely).

I've been sick the last few days, so I haven't gotten back out to work on it. The plan is to have a look at those coils. Make sure the cam cover isn't leaking, look at the wiring and maybe replace the plugs with the OEM NGKs.

 

We have a smoking gun. I pulled the #s 1 & 2 coil and plug today and found the #1 coil boot to have corrosion inside the boot. The #2 did not have any corrosion. The plug wells were dry. I cleaned out the corosion and it's running fine now.

There must be water getting into the #1 plug well (maybe #2 also). It could be that this was just me kicking myself when I rinsed off the motor with a garden hose after changing the water pump (how else to get rid of all that coolant - and yes, I drained it from the radiator drain). Or it could be a sign that water is getting into the plug well when it's raining. The upper coil seals seemed fine to me.

If anyone can report a similar issue, maybe it's a rain issue. If not, it's likely just another occation of me kicking myself in the nuts.

 

Two things:
Question: How have you determined that the coils were failed?
Comment: High voltage does not see a little corrosion as an impediment to current flow. It is usually more of a problem at low voltages, the lower the greater the problem. It may see the presence of corrosion as an alternate path to ground, but that would take a complete path to make it happen and a little moisture to create a conductor.
OK, three things:
Can you correlate the rain (or other H2O) with all of your previous coil failures? That would be a requirement for a valid SG.

 

I read the codes indicating a coil failure. In all prior occations, I either moved the failed coil or swapped it for a new one, confirming the failure.

That copper corrosion is more than enough of a path to short out the high tension side of a coil.

I cannot correlate rain with prior failures. Although that's the basis of my question here. Has anyone else expereinced front coil failures? Or am I the only one that drives these things in the rain? lol

What's a SG?

 

I do, but I tend to keep the bonnet shut, which keeps it off the engine.

What do the plugs look like?

 

Do not wash these engine bays with a garden hose. Way too many electronics to ruin....

 

To be clear, this is an open hose. No pressure. Just water running gently out of the hose. No nozzle, no thumb.

If you dont wash an engine off after you change a water pump, it wil stink of coolant for weeks.

Thanks everyone.

 

Coolant smell will be much less of an inconvenience than damaged electronics.

 

Thanks for the help. You guys can close this thread.

 

Did you discover the originating issue? I'm curious.

 

SG refers to your smoking gun reference.