P0304 code - under 100k and under 10 years - take to dealer?

illyc

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just threw P0304 (misfire in cylinder 4) and have experienced typical symptoms of coil problems for a couple weeks now on and off.

my car is a 2004 (bought in August 2004, so under 10 years old) and 84k miles - thus qualifying for the 10 year/100k mile extended warranty. but i just bought it in September and am not sure if this service has been done before now.

dealer will do diagnostics for ~$100 and if it's warrantied, will waive the fee but if it's not, will charge me that fee. do i take it in or just bite the bullet and address this myself? or take it to an independent? is there a possibility this isn't warrantied?

i have the ability to do this myself if necessary. i know this issue has been addressed a million times on here, just looking for opinion taking to dealer. i'm in Asheville, NC if anyone has any connections/rec's.
 
MOST likely from what I've read about other peoples experiences, the dealership will replace just the misfiring coil and plug (~$60). If you complain enough you can sometimes get them to replace them all (~$500). So the $100 diagnostic fee may not be worth it if they are only going to replace the 1, (you can save $40 doing it yourself) but it would be if they are willing to replace them all.
 
... So the $100 diagnostic fee may not be worth it if they are only going to replace the 1, (you can save $40 doing it yourself) but it would be if they are willing to replace them all.

Your math is a little off. If they find that at least one of the COPs is bad (the odds of this are really good), then there is no diagnostic fee.

For illyc, the main consideration is this: They will only replace the COP(s) (and associated plugs) that currently test as marginal. Experience here is that more will probably fail soon. So, he can go to the dealer a few times (as failures come up) and get them all replaced at no charge except for hours of his time, or he can replace them all at once himself at a cost of $400ish and a couple of hours of his time.
 
Ah I did not know they waived the diagnostic fee if they found something at fault. I don't have the warranty only going on what I've read previously on the forum.
 
In my experience, at least one of the coils will be marginal. The chances of you having to pay the diagnostic fee are probably slim.

In my case I brought it in when I felt a slight misfire (no cel). They did find 2 bad coils IIRC and replaced them along with the plugs for those. They tried to talk me into replacing all the plugs which would've been pointless... 2 weeks later I felt another misfire, I took off the passenger coil cover and saw a little bit of oil on the boots. Brought it back, had a nice chat with the service manager. When it was all said and done they replaced all of the coils, plugs, vcg, and the wiper cowl. (I know the 03s only had the vcg coverage).

I think some service techs will just take shortcuts and not stress test all of them (only the cylinders the computer says are misfiring). I'm not entirely sure how they get these warranties approved, but it seems like they have some leeway to just do them all. After all, it would be cheaper to just do them all upfront instead of having that vehicle come back every 2 weeks.
 
any precautions i need to take if i go to the dealer? do yall go out with the tech and watch them pull codes and whatnot? i have little experience with my local dealer.
 
so I'm getting the original buy/sale date off of the carfax - is that reliable or is there somewhere else I can get that from?
 
so I'm getting the original buy/sale date off of the carfax - is that reliable or is there somewhere else I can get that from?

That should be right. Otherwise, the stealership can tell you over the phone.
 
well dropped by last Friday and inquired re: extended warranty. dude knew a little about it, quoted me $90-120 for the diagnostic IF work wasn't covered under warranty. took it in today around 2, guy called me around 5 and told me they replaced the ONE failed coil under warranty and it was ready to P/U.

oh well - hopefully i'm not doing this again in a few weeks with a different coil. at least i'm not paying any $$!!
 
just threw P0304 (misfire in cylinder 4) and have experienced typical symptoms of coil problems for a couple weeks now on and off.

my car is a 2004 (bought in August 2004, so under 10 years old) and 84k miles - thus qualifying for the 10 year/100k mile extended warranty. but i just bought it in September and am not sure if this service has been done before now.

dealer will do diagnostics for ~$100 and if it's warrantied, will waive the fee but if it's not, will charge me that fee. do i take it in or just bite the bullet and address this myself? or take it to an independent? is there a possibility this isn't warrantied?

i have the ability to do this myself if necessary. i know this issue has been addressed a million times on here, just looking for opinion taking to dealer. i'm in Asheville, NC if anyone has any connections/rec's.

Under warranty, take to dealer! Each COP can cost $50+ a piece for correct part!
 
ended up throwing P0304 and 0501 - they replaced 2 coils under warranty. running SMOOOOV.
 

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