New Ignition Coil Thoughts

[Caretaker]

I'm at 103,000 miles and contemplating putting in fresh ignition coils to my 2ZR engine. I took out the coils and already replaced the spark plugs with Denso Iridium plugs, and after inspection returned the OEM Denso (part #90919-02252) coils back in last year. New Denso ignition coils however are as low as $76 on rock auto's website + shipping. I am now looking at the Delphi ignition coils (part# GN 10341). They "appear" to be well made from the research I've done and are as low as $31 each on the internet. They come with a 3 year/ 36 month warranty as well. At that price, I don't feel like I'm breaking the piggy bank to put in fresh ignition coils. I sometimes get a slight rough idle at initial startup and although I have not had a triggered engine light/code, I figured at $31 a pop, it could not hurt to put in the Delphi ignition coils. Any opinions out there on the quality or lack thereof regarding the Delphi brand? They certainly make a lot of ignition related stuff and again, the research I've done seems to point to a positive product line. Thoughts?

[Jbenrod]

I think the Delphi coils would be fine but I also don't think you need to be changing them now. Wait - with more time something else will show up that needs attention. Maybe just give the car a good wax job for now.

[Caretaker]

Both of my mechanics on each coast would tend to agree with you. However, as a Fit owner, the ignition coils are a source of trouble after about 100,000 miles. I have changed them out in that car; as for the Vibe, given my minor shakes when in neutral and when I first start the car (sometimes), I thought it could not hurt to replace them at $30 a pop. Moreover, I have had a jumpy tachometer for the past few years, to include a shudder in the engine when coming to a full stop where the RMPs dive down a bit too low. Things like the PCV, intake manifold gasket, and ignition coils can't last forever, and in the case of the latter, are a simple job to replace myself.

[joatmon]

I wouldn't expect the coils to need to be replaced at the mileage on your car. Would a weak or intermittent spark result in tell tale deposits on the plug?

I can relate though. If you replace the coils and it doesn't fix the problem, then at least you will have eliminated them as a possible cause for the problem, and for me, sometimes the easiest things to replace make it to the top of the list of possible cures.

I don't know if I've used Deplhi parts, but wouldn't have any reservations about them as a brand. For Vibe parts, I've only heard to stay away from Bosch, but that's not first hand experience either.

[vibrologist]

Both of my mechanics on each coast would tend to agree with you. However, as a Fit owner, the ignition coils are a source of trouble after about 100,000 miles. I have changed them out in that car; as for the Vibe, given my minor shakes when in neutral and when I first start the car (sometimes), I thought it could not hurt to replace them at $30 a pop. Moreover, I have had a jumpy tachometer for the past few years, to include a shudder in the engine when coming to a full stop where the RMPs dive down a bit too low. Things like the PCV, intake manifold gasket, and ignition coils can't last forever, and in the case of the latter, are a simple job to replace myself.

The symptoms you mention might as well be caused by a vacuum leak. Teh intake manifold gasket and the TB gasket would be prime suspects.

The jumpy tach could be an electrical problem in the gauge cluster or you may have an issue with the alternator.

[Caretaker]

Thanks gents. Appreciate the input. I ordered the Delphi coils from Herko down in Miami. On their own website, they are $4 cheaper for the set of four than on their ebay site, bringing the total to $117 and change. No tax, no shipping costs. At just under $30 a pop, I'll throw them in and see what happens. Given that these sell for $50 each plus shipping on rockauto.com, I'm considering this a steal. Once proven wrong, I'll consider going back to my mechanic to have the intake manifold gasket and PCV replaced since it is a pain in the (removed) to get to the PCV on the second generation Vibe. I'll also have him clean out as much carbon as he can see once he has the manifold off. My new mechanic here in Oceanside is excellent and believes my problems are just carbon related. Nevertheless, I still contend that a PCV and ignition coils, like spark plugs and air filters, are routine maintenance items that should not wait until they fail. When one Denso ignition coil costs $70+, I'm thrilled to get the Delphi set for such a low price.
My alternator crapped out over a year ago and was replaced (obviously), so I know that it is not the cause of the problem. Having gone through that experience, I can tell you..........when it goes, it really goes. I initially stalled out at a gas station, and after 3 jump starts, was able to make it a couple of blocks to a service center. That was my first real "break down" in decades and I was very fortunate to have it happen at a Costco gas pump.
At 103,000 miles, this car is just getting broken in. It is running fantastically, getting 30 mpg every fillup whether I am driving 80 on the highways here or in traffic. I'm just trying to get rid of this intermittent engine rumble that seems to happen during moist mornings at startup, or 25% of the time when coming to a full stop when crawling to a stop sign or when in stop and go traffic.

[joatmon]

... here in Oceanside ...

guess I wasn't paying enough attention and missed it. We still here in the Delta Quadrant are sorry to see you move away, but glad you'll be free of the total chaos snow can bring here