[benzy89]

Originally Posted by BlueBimmer

thanks - car is due at the dealer in 2k to get plugs, what's the maintenance period for coils - is it replaced under factory warranty like plugs @ 45k?

Plugs & Coils usually last between 15k-20k depending on how aggressive a tune you're using. Obviously if you run a Stock Map more often, they'll last a little longer (25k-30k), and I don't think they'll be covered under the warranty. Most people go with Bosch or NGK plugs (either one it's about $10-$15 per plug) when they replace. The Bosch plugs are the exact same ones BMW uses, except it doesn't say BMW and cost 1/2 as much. The NGK plugs are a little more performance oriented & are about the same as the Bosch (maybe a dollar or 2 per plug).

As for coils, unless your car is on a track, keep using the OEM style coils. There are super performance coils (more for track-only cars) from a company called Okada, but they run ~$1,200 for a box of six.

[BlueBimmer]

Originally Posted by benzy89

Plugs & Coils usually last between 15k-20k depending on how aggressive a tune you're using. Obviously if you run a Stock Map more often, they'll last a little longer (25k-30k), and I don't think they'll be covered under the warranty. Most people go with Bosch or NGK plugs (either one it's about $10-$15 per plug) when they replace. The Bosch plugs are the exact same ones BMW uses, except it doesn't say BMW and cost 1/2 as much. The NGK plugs are a little more performance oriented & are about the same as the Bosch (maybe a dollar or 2 per plug).

As for coils, unless your car is on a track, keep using the OEM style coils. There are super performance coils (more for track-only cars) from a company called Okada, but they run ~$1,200 for a box of six.

So should I even ask the dealer to change coils when they do plugs or is it out of the question? Is there a maintenance spec for when coils should be changed or are they one of those "only if they fail" items?

[benzy89]

Originally Posted by BlueBimmer

So should I even ask the dealer to change coils when they do plugs or is it out of the question? Is there a maintenance spec for when coils should be changed or are they one of those "only if they fail" items?

You can ask, I know when I bought my car I asked when the coils/plugs had last been changed. When they told me some had been recently replaced, others still had the originals in (car was bought @ 27k), I requested that they be changed prior to purchase.

Post purchase, those parts are replaced "as they fail", which is usually determind when misfires start occuring on a specific cylinder. Important to realize that not all the cylinders undergo the same stress, so Cylinder 1 may need its Plug/Coil replaced before Cylinder 4 needs its Plug/Coils replaced. IMO, if you're doing a major mod upgrade (Going FBO, upgrading to RB Turbos, etc) it makes sense to replace all the plugs/coils if you're in that grey "failure" mileage (~15k). I'm about to go FBO, but I've also only had my new plugs/coils in 3k, so I'm not concerned.

[BlueBimmer]

Originally Posted by benzy89

You can ask, I know when I bought my car I asked when the coils/plugs had last been changed. When they told me some had been recently replaced, others still had the originals in (car was bought @ 27k), I requested that they be changed prior to purchase.

Post purchase, those parts are replaced "as they fail", which is usually determind when misfires start occuring on a specific cylinder. Important to realize that not all the cylinders undergo the same stress, so Cylinder 1 may need its Plug/Coil replaced before Cylinder 4 needs its Plug/Coils replaced. IMO, if you're doing a major mod upgrade (Going FBO, upgrading to RB Turbos, etc) it makes sense to replace all the plugs/coils if you're in that grey "failure" mileage (~15k). I'm about to go FBO, but I've also only had my new plugs/coils in 3k, so I'm not concerned.

My Cobb is at home and I'm at work (can't wait). If it causes misfires it might be the trigger for them to be replaced.

Thanks for the helpful input!!

[benzy89]

Originally Posted by BlueBimmer

My Cobb is at home and I'm at work (can't wait). If it causes misfires it might be the trigger for them to be replaced.

Thanks for the helpful input!!

Update as soon as you get back from the 1st WOT with the tune

Just a heads up, when you plug your AP into your laptop, you might have to update the firmware. Not a big deal, but just so you don't get surprised/pissed when you go to load your maps & that message pops up.