voyard

I have a 97 Maxima with 123000 or so miles. I love my MAX but this problem is driving me nuts, and it's getting expensive. My car has been stalling at idle and smoking gas-rich exhaust, especially under acceleration. I took it to my mechanic twice. The first time, he said I needed a tuneup and some other thing. Quoted me 195 bucks. I could have done the tuneup my self, but since he had the car already, I figured I'd let him do it. a small price to pay to get my car back right away. Complete the tuneup, plus replaces the coolant sensor, for 230 bucks.

Get the car back, runs great. Next day, same thing. I have to put it in neutral at lights to prevent it from stalling. And gas is eaten by the gallon! Take the car back the next day, he keeps it for a few (5!) days. Checks the codes since the CEL came on. Came up with multiple misfires, knock sensor and I believe O2 sensor. He seems kinda baffled, and even though he is a nice, honest guy, he's getting old and doesn't seem to have a clue. The car was driving well he said, so I took it home and decided to figure out what I was going to do.

The WHOLE day after, I had NO problems! Ran great. Then the next day, in the late morning, it started to ride rough, and got worse throughout the day. By afternoon, it was riding pretty darn rough. It really felt like I had a cylinder or two out. SO here's what I have done:

- spark plugs, fuel filter, air filter, oil and filter, and coolant temperature sensor was changed
- Checked MAF, looked up records and it was changed less than 15,000 mile ago, and it
was spotless
- Checked for vacuum leaks, did not find any
- Cleaned throttle body (was pretty clean already)
- Cleaned all sensor and electrical connection (took a while!)

So after a TON of research, I'm inclined to think that the main culprit is the coils. They seem to be a popular failure item in A32 Maximas. Will a bad coil cause the smoking as well? Here are some clues:

- Runs much worse with air on. At one point, it actually stopped briefly when I shut the air
off. But now it rough running all the time.
- I changed the alternator about a month ago. The problem started 2 1/2 weeks ago.
Thought is was the fuel pump, because it would even start after it first stalled. And also,
the first time it stalled, CEL came on and off like crazy. Now, it just stays on.
- I just noticed that now since it's idling really rough, I think I head a faint ticking, but it
could be something else.
- I started the "eliminate the coil pack" test. I did the three on the firewall side, and car
was idling somewhat worse, especially when I gave it some gas. So I assumed those
were okay.
- It starts up right away. No startup issues.
- Have gone through almost 1/2 tank in only 40 miles.
- Water level are fine and there in no leaking, so there is no blown head gasket issue for
the smoking. Smoke is grayish. Exhaust is gas-rich

SO let me know what you guys think. BTW:

-Can a bad knock or O2 sensor cause these problems with the super rough idling?
-Where is the other coil packs? I found the three on the firewall side (is it under the intake
manifold, crap!)
-Can a bad coil cause all these problems, including the smoking
-Can my air conditioner cause any of these problems?


THANK YOU ALL. Any help is greatly appreciated.

voyard

I did a basic coil test by removing the coil connection one by one to see the change in the idle. I noticed two coil packs that did not respond. So, I purchased two coil packs from my local AutoZone, replaced them, and guess what? Still the same problem. The coil packs are fine. What's next, the injectors maybe? Now I gotta return those and get either injectors, or something else. Any info you folks have would be invaluable, Thanks.

Z_Tuned_R34

Nah thats not an A/C thing or Coil packs or O2 sensor.
With rich exhaust smell usually its your Cat. Converters making that smell when they go bad. and in my freinds case with his Kia his cats did choke his and kill it all the time, he changed the oil and still had a rough idle(what a pos lol). Though it did stop when he changed his cat. thats what it sounds like to me.

voyard

would the cat smoke as well? Could it cause the cylinder to randomly miss?
Question, I have noticed a little moisture from th tailpipe when I rev it pretty hard. Could water in the oil cause these symptoms??? I know it's not the gasket, but what if water did actually get into the oil? We had some pretty bad rains for a few weeks. Looks of deep puddles. Gonna change it and see what happens, because right now, it's running fine. Go figure...

Z_Tuned_R34

does it run really hot? Water in tail pipe is condensation thats normal.

voyard

Nope, runs good temps. Not losing any water. Exhaust smells kinda gassy, and kinda weird. Not really like oil. Like stale water and gas actually. Like gas that sat in the lawn mower that sat outside forever. I have already went through a tank of gas, so the gas is fine.

Z_Tuned_R34

Id change my O2 Sensor first if it is bad. then see how your car acts.

acooper5

hate to revive and old thread but my car is doing the same thing with white smoke. Did you ever find a fix for this? Any help would be great.

Akito

If I remember correctly, white smoke is coolant leaking into your cylinders, blue smoke is engine oil burning, and black smoke is something is really wrong.
If your car is doing exactly what voyard's maxima is doing, I would:
1. Always check your codes if you have any first. Check for ghost codes too.
2. check fuel injectors being stuck open causing gas to flood the cylinder, hence gas smell and a really sh**ty mpg.