Sooooo I'm nervous. P0300 and white smoke.
 

Yes I searched and got nothing that really helps me. If you know of a thread with similar issues please point me in the right direction.

You can see axactly what my car is and what mods I have in the sig.

While driving home on I95 tonight I felt like opening up the max a little. I ran third up near redline and let off. No issues at all at this point, pulled hard with no miss at all. About 2 miles further down the road I pulled off to see my girlfriend at work. Spent about twenty minutes there and go back out to the car. I start it up with ease and it runs fine.

Here is where the problems begin... I get about 300 yards down the street at a low RPM (4th gear at about 30MPH) and the steering gets very stiff. I look down at the tac and the car is off... I try to crank it up and it takes about 5-8 seconds to start. Once it finally starts up if runs VERY rough. Almost like I'm down 2 or 3 cylinders. I get out to check it out and I have a decent amount of white smoke at idle and more when I rev it up. The smoke has no blue tint and doesn't smell too sweet (head gasket) but def has a different smell so I'm kinda lost.

The car almost sounds like an STi with exhaust when driving (you know how they sound). It revs up with a slight miss and no backfire. I'm lost here guys. Any help? I was lucky I had the OBD2 with me. The only code is P0300. I plan on going in the morning and checking the coolant/oil for head gasket issues.

Thanks a ton in advance!
Josh

If you don't feel like typing you can call me at 540-455-3295. I'll be up for a while as I probably won't get much sleep tonight
Thanks again

A few possibilities that match the code and the performance:

1. MAF is blown
2. At least one coil is blown
3. This is from a 4th gen thread, but should apply to you as well:

And hate to tell you, but based on what you were doing with the car just before it happened, it very well could be a blown head gasket. Would explain the white "smoke" from the exhast and you wouldn't necessarily get that "sweet" smell depending on your antifreeze mix and brand...

Again, though, most likely is tha you have one or more bad coils and/or a defective spark plug. Start with checking your plugs, coil wires, and do the coil resistance check (there's a thread around here on it, It's a long one and i saw it within the last week or so on the 5th gen first page..)

Thank you very much! I am thinking possibly Cam position sensor also? Merlyn told me that if the crank position sensor went bad that i wouldn't have a tac so I kinda ruled that one out. Thanks again!

That's what I'm afraid of (head gasket). I'll try those tests tomorrow.

anything is possible, but that doesn't sound like one of the usual culprits for this code. Most people who get P0300 (or 0301, 0302, 0303....etc) have one or more bad coils or a bad MAF. Both are common items to go bad (I'm on my 4th MAF and have replaced every coil once or twice).

looks like Dave will be getting a call tomorrow :) Thanks again man!

here's the thread that shows how to test your coils. And this method DOES work if any of the coils are totally bad. If it's just an occasional misfire/coil's not that bad, it might not work.

In your case, though, you clearly could have one that is totally gone and this test will show you if that's the case.

http://forums.maxima.org/5th-generat...ow-w-pics.html

wow, That's an awesome write up. Thanks again! That test will be run tomorrow first thing. I hope this or the MAF is the issue. How much of a pain is the Head Gasket?

huh, i didnt think 5.5's really got bad coils. i guess it makes sense though, nothings bullet proof. i guess ill check that now, been getting the p0300 everytime i go to the track, hopefully it will help me fix the p0167, p0147, p0706 i just pulled too (yes im checking the stickies for what they are) :hide:

doubt its the HG it woulnt just go, u would have had to overheat the car, have really crappy coolant for the longest time. the max engine is strong really doubt its the heads.

Yes it would.
Also, running the car to readline would do the trick too if there were any weak spots in the gasket.

Think I found the problem. Got a couple bad coils.

If you're worried about that head gasket just perform a compression test on each cylinder and compare!

Are you SURE your coils are to blame, I know you told me you pulled one by one (as suggested) and it was a noticeable difference BUT... if you just take your IM off and pull your plugs you might have just killed a few plugs. I see you blowing 2 plugs more likely then blowing the coil. No use in buying 6 new coils if you have 2 bad plugs. The car has 115K~ on it, who knows when the plugs were replaced last, but I would at least pull a front plug (I know you think the coils in the rear are to blame) and look at it, because it might be time to replace the plugs anyway, and since you have to take the IM off to get to the coils, you might as well just double check, or just replace them anyway since you are already there and they are about due for a change (if you don't know when the last owner changed them). I know I did mine at about 60k which for my choice of plug changes, would put me at about 120k when I would change again (maybe sooner).

Do you still have any cats on the car? could be a failed cat or o2??
If the coils turn out to be OK, I would look there. . .

It has 106K not 115K. And the plan all along was to go down to the car and pull the IM today and check plugs. Don't worry, You will get your money.

dude I'm just messin with you :-P btw... 115k~ = 115k give or take 10 :-P that is how I look at it...

I'm not worried about my money, you know that :-D

I do have cats. But it is something with the fuel/plugs. Smells like straight gas and when i unplugged those 2 coils there was no difference in idle unlike when I unplugged the other 4 and the car near stalled out.

I got ya man. We hooked up the sub and amp last night in chris' car. That f*cker is LOUD. That lil Forenza sounds like it's gonna fall apart:)

Like I said, my setup was not complete so it was a great amp / sub combo when it was in its prime on my car. Glad he likes it... Maybe the bass force will give him 5 - 10 HP

yea, we have the sub turned to the rear so that when it hits it gives the car a little boost...

Shamefull bump, Replaced all plugs and swapped the coil packs that were in question to the front... The same 2 cylinders (1 & 3) are still screwed... anything? Just got off the phone with DaveB and he says fuel pressure regulator? Anything would help. Thanks
Josh

Might wanna do a compression check since they're adjacent cylinders...

Actually a pretty good idea.

I'm telling you...in the tank. A33Bs+ are a returnless setup, with the regulator in the tank.

If it's dumping fuel, then it's most likely the injectors.

I vote MAF, had a customers 4th gen do the same thing, Multiple cyl misfire and once in awhile it would narrow a cyl down, mostly #3. I tested everything, changed plugs, it stopped doing it for about 15 minutes, then smoke and miss. After messing with it for hours, started pulling sensors and such off my car to try it out. MAF fixed it. They do some weird stuff when they're bad.

ok i believe you. I probably didn't hear him right. Thatnk for the parts you got me :)

i'll try another one soon. thanks

so no code for the MAF came up??

Nope none at all. Only misfire codes. And a lean bank 1 once I believe, but no MAF code at all.

Well it was a stuck injector. Maf WAS fine but it went when I went to drive it home. Jesus this is getting old.

$20...


What about Merlyn's MAF (or your old one, whatever) didn't swap that one out?

$20 for what? And the other MAF is getting put in tomorrow. Just to make sure that is the issue. The 350Z injectors are great. Pulls a little harder top end it seems.

For the car, remember?

I think the 'pulling harder' is all in your imagination, really.

haha just add $7980 and you can have it. It probably is in my head. Hell man, I have been driving a work van for a couple weeks :). How is his new car?

It's a VW. That pretty much says it all...

ha! night bro

:D saved.