Several questions regarding 1997 Q45t (very long post)...

[aez987]

We have a 1997 Q45t. A few weeks ago the car began to stutter and stumble. Shortly afterwards, the Check Engine light came on.

We took the car in to Infiniti for service. The Service Technician told us that the #1 coil pack was bad, plus it was time for new spark plugs. In addition, he suggested that we replace all 8 coil packs, because once one goes out, they tend to fail one after another (I never heard that before, though). Anyway, all eight coils would have cost over $2000!!!

As a result, we had them replace only the #1 coil pack and all 8 spark plugs. The car ran fine for about 5 days then the same thing happened - Check Engine light and stumbling.

So, I looked under the hood and there was an ENORMOUS collection of corrosion on the battery terminals. I replaced the positive terminal and cleaned up the negative one thoroughly. In addition, I put on a new gas cap. So far, after 2 days, it's been okay. My questions are:

1.) Is it likely that all of the coils are starting to fail?

2.) How can I test the coils to see if they are okay?

3.) Is this a common problem with the Q, if so what is the normal remedy?

4.) Would the corrosion on the battery cables have increased the resistance so much that it threw off the car's electronics?

5.) Finally, how do I remove the front lens cover on the driving lights? I want to remove the 'glare guard' like I did on my 300ZX. I know how to replace the bulbs, but can't seem to get the actual lens off even after removing the clips.

Thanks in advance for your patience, and for any assistance you may provide me. Take care.

[Jesda]

Welcome to NICO!

1. It is extremely rare, but not impossible for a coil pack to fail.

4. That is entirely possible, and a bit dangerous on modern vehicles that rely so heavily on computers and other electronics.

2, 3, and 5. Someone else can chime in and answer that.

[DAEDALUS]

You can ohm the coils, but failure begins to happen only under high voltage, when arcing occurs. You'd have to test voltage between the coil and plug, which isn't easy. Definitely not common. Normal remedy is to replace the coil. Corrosion usually happens outside the post/terminal contact area, but if it gets between the 2, I suppose it could. If either terminal feels warm/hot I'd suspect it was a problem.

[3Q Jay]

i also have a 97t. all original coils at 87k. [likely original plugs, too by my reconing---i bought the car with 78k]. i recall some posts by Qtech, wherein he states that the coil pax on the fy33 are lighter and cheaper [read --more prone to fail] than on the g50. he also mentioned that failures are likely to occur after the first plug change due to handling, etc.

so, i'm probably not giving you a warm feeling given that you just had the other 7 handled. what does Joe charge? gotta be less than $2000 for 8.

DAEDALUS--do you know if the g50 coils can be put on an fy33? that would seem to be a heavy duty replacement if they work.

[aez987]

Thanks for the feedback. Very informative.

Anyone fimilar with the driving lights? Anyone ever hear a "glare guard" - does the Q have one?

Thanks again.

[metaverse3]

Well, if the same thing reoccurred after a supposed fix from the dealer, it is obvious the coil was not the original probem. However, I will say that coilpacks do fail. they crack and arc against the manifold, causing ignition issues leading to stumbles and dead misses of base idle. Coils do not fail in sequence.. A coil can weaken, a coil can crack, but, they don't high-five each other on the way out. You did do the right thing by replacing one coil since it is obvious that was not probably the original problem to begin with. Common problems are grounding issues...judging by the corrosion fix from the battery terminals. Take the car back, and try to get your money back for a possible bad part replacement.

[maxnix]

Anyone fimilar with the driving lights? Anyone ever hear a "glare guard" - does the Q have one?

There are no "driving lights," only fog lights.

Have never heard of glare guard. Sounds like the Vortex supercharger.