Ignition coil getting burned out

[Sean & Ian]

[Disclaimer: I am just a regular Prius driver with no mechanical knowledge; please excuse my ignorance that may be apparent in this thread]

Yesterday, the check engine light came on. Before then I observed extreme jerkiness at engine start-up. It was like the engine couldn't decide whether it wanted to start up or shut down. My Toyota dealer diagnosed that the ignition coil had burned out, because of some water that got in there.

I have never washed the engine. I didn't go through big puddles. Has this happened to anyone? How else can water get into the ignition coil area?

Thanks for sharing your thoughts!

[Patrick Wong]

Originally Posted by Sean & Ian

...My Toyota dealer diagnosed that the ignition coil had burned out, because of some water that got in there.

I have never washed the engine. I didn't go through big puddles. Has this happened to anyone? How else can water get into the ignition coil area?

Prius has a separate spark igniter for each spark plug. If you take a look at the top of the engine, you will see four dark rectangular assemblies mounted to the cylinder head cover. Those are the tops of the spark igniters.

Water can drip down from the cowl above the engine, onto the engine. If this happens and if the rubber seal on the igniter is not working, then water will enter the spark plug well. Only one small bolt holds the igniter to the cylinder head cover, so it is easy for water to get in. [This is one reason why using copious amounts of water to wash the engine is a really bad idea, although I know you did not do so.]

If water gets into the spark plug well, this will cause spark plug misfiring and damage to the spark igniter. Hence, the driveability issues that you noticed. Toyota issued a TSB on this condition; see attached file.

• How many spark igniters were replaced?
• Was it necessary to replace the spark plugs as well?
• Did you take a look at the replaced parts; if so what did they look like? Did you see corrosion on the bottom of the igniter?
• What did you pay for the repair?

[bwilson4web]

Originally Posted by Sean & Ian

[Disclaimer: I am just a regular Prius driver with no mechanical knowledge; please excuse my ignorance that may be apparent in this thread]

Yesterday, the check engine light came on. Before then I observed extreme jerkiness at engine start-up. It was like the engine couldn't decide whether it wanted to start up or shut down. My Toyota dealer diagnosed that the ignition coil had burned out, because of some water that got in there.

I have never washed the engine. I didn't go through big puddles. Has this happened to anyone? How else can water get into the ignition coil area?

Thanks for sharing your thoughts!

There was a technical service note about a problem with water getting in the ignition wiring and spark plug wells. I don't know the number but this is exactly the expected failure mode.

Bob Wilson

[Sean & Ian]

• How many spark igniters were replaced?

Based on the invoice, only one ignition coil was replaced -- "REPLACED CYLINDER #1 IGNITION COIL AND SPARK PLUGS"

• Was it necessary to replace the spark plugs as well?

Yes, they replaced 4 spark plugs.

• Did you take a look at the replaced parts; if so what did they look like? Did you see corrosion on the bottom of the igniter?

Unfortunately, no...

• What did you pay for the repair?

$0; the extended warranty paid for it. Without it, I would have paid $450.80. Of which, parts are $131.78 and labor $319.02. I think the diagnostics took a long time before they determined the cause.

Thanks!!!

[hyo silver]

I had to pay for two coils and two plugs after a particularly rainy highway trip last fall. No extended warranty, and Toyota refused to cover it. Apparently there was a service bulletin or something about a hood seal near the wipers, but they claimed to know nothing about it. One of my neighbours teased me once about not being able to drive an electric car in the rain. I thought it was funny at the time.

[Patrick Wong]

Originally Posted by hyo silver

I had to pay for two coils and two plugs after a particularly rainy highway trip last fall. No extended warranty, and Toyota refused to cover it. Apparently there was a service bulletin or something about a hood seal near the wipers, but they claimed to know nothing about it...

Yes, if you are interested in reading the TSB, I attached it to a prior message in this string. Please note that the existence of a TSB does not mean that the problem is automatically covered under warranty.

[hyo silver]

Thanks, Patrick. I've printed it out and will be plugging that gap. Still, I find it extremely annoying that I'm on the hook for a $500 repair which could have been avoided had Toyota taken responsibility for its own errors.

[Hoopla]

I have a 2007 Prius and it's in the shop and the techs are stumped -- the code said to replace the ignition coil, so they did that. They took it on a test drive and it died within two miles. They restarted it and brought it back to the shop. Took it on a 20-mile test drive adn couldn't get it to die again, but don't feel the car is "fixed," so they still have it.

Any ideas? Here's what led up to this: Two weekends in a row, I got the "triangle of death" and check engine light. The car would hesitate and shudder and not really respond when I hit the accelerator. I'd have to pull over, turn it off and re-start it again to get home. After letting it sit, the warning lights would go away. Finally brought in in on Monday and now it's Wednesday and no solutions. Help!

[bulletprooffool]

I have just checked an error message on my 04 Prius and gotten a P0301 message.
I believe the warrantee is 3 yrs / 36000 miles - whichever comes first, so I am out of warrantee
Can anyone give me any indication as to how to verify this before I squander money on Toyota 'fixing' a design fault (If it is in fact the same problem)

[bulletprooffool]

Originally Posted by bulletprooffool

I have just checked an error message on my 04 Prius and gotten a P0301 message.
I believe the warrantee is 3 yrs / 36000 miles - whichever comes first, so I am out of warrantee
Can anyone give me any indication as to how to verify this before I squander money on Toyota 'fixing' a design fault (If it is in fact the same problem)

anyone?