I posted a while back saying my car would smoke through the tailpipe and felt like the it would shut off after the car was restarted. It use to only happen after I drove it for a while and the car was warm. Today after I got off of the highway, it did the same exact thing except that it did it while in motion. The rpms kept dropping and the muffler kept blowing a lot of dark white smoke. It smelled awful. The car doesnt overheat so I outruled a blown headgasket. Somebody said about a bad MAF but I cant find anyone to exchange and test. Some reason I dont think its the MAF either. I dont want to take it to the dealer because it does not always do this and might not show these symptoms when they look at it.

On a side note, something strange I noticed, while unsuccessfully trying to remove the knock sensor I noticed a foam like cushion or something behind the KS. Is it normal for it to be there for shielding heat or is part of a cover up of some sort?

 

Never saw no cushin by the KS. I wish there was a cushion down there... I wouldnt have sliced my hands to peices.

Sounds awfully like a blown headgasket but I dunno since you said it dont overheat? Take it to teh dealer, i think they still got that 120point inspection or something..

 

I did take it for that inspection but they found things like all the struts, tranny oil, etc need to be replaced. Nothing along the terms of my problem. The Temp gauge always stays in the middle, Thank God !

That cushin thing is way inside, not next to the KS but way after it. I wonder if its keeping something intact.

 

is your coolant level going down??? white smoke means theres combustion of coolant taking place, mark off the level of the coolant and see if it keeps drawing from the reservoir

 

a heavy plume of white smoke could mean a rich fuel mixture.
One of your injectors could be sticking open making it dump gobs of fuel into the engine. Get some injector cleaner and see if it helps.
Plus injectors normally act up when the engine is at its normal operating temp.
Another way is to record voltages across each injector and you can know which one is bad. Your dealer could help you out on that.

 

Update:

I took it to the dealer and told them about the problem. The guy said they wont be able to look at it later and what not. I told him that the car does not do this when its cold and I dont want to leave it there all day (and pay 100 bucks) for nothing. I kept hte car running with the chance of hoping that one of the techs would come see it right away. That was a bad idea as the car kept really smoking and the check engine light finally came on.


I got excited and checked the codes, I got 0701..which means multiple cylinder misfires etc. As I pulled onto the street, the car would not start again at all. So I was about to call the tow truck when all of a sudden after like 15 tries, the car finally started. It was smoking a lot more than it usually does. So I drove it to my mechanic as fast as I could with the fear of it shutting it off in the middle. So its at my mechanic right now and he will let me know what to do and what needs replacing. What do you guys think? Coil packs or injectors?

BTW, I kept restarting the car in front of him and the SOB started right up everytime without any smoke or shuddering. Jeez.

 

No responses? I expected lots.
What can I do guys? My mechanic is clueless.

 

check ignition lines for signs of corrosion, try reseting the ecu, test to make sure all cyclinders are firing, test all coil packs, check all spark plugs for signs of unusual wear, etc. And as mentioned earlier, check coolant levels, and also check your coolant temp sensor and connector, as your engine might be overheating, while a malfunction coolant temp gauge could be giving a normal reading. Also, check compression in each cyclinder, as that might help refine your search, good luck.

 

Maybe a blown head gasket.

I would think coolant in the combustion chamber would cause a misfire. It would also produce white smoke. Maybe the gasket has a crack in it that seals itself up when it gets hot.

Those are my guesses.

 

Another little update:

My mechanic looked it over and gave it a major tuneup which includes spark plugs, gas filter, air filter etc. He said the plugs looked really bad and needed to be replaced. Then he said one of the Ignition Coils is bad and needed to be replaced. - Do you guys think that a bad ignition coil could be the culprit or it was partially to blame?

I can just imagine the same problem coming back when I get the car back tomorrow. The whole tuneup, tranny oil change, ignition coil, knock sensor labor is costing me $400 bucks. I know about doing it myself but I dont have the tools nor the place or time.

 

Balle Balle Bump

 

Your mechanics prices actually sound pretty fair. IMO, the car should be at Nissan. They've got the service manual and equipment to correctly diagnois problems like this. A regular mechanic that doesn't work on Nissan products may not be able to trouble shoot the right equipment. With a service manual and volt meter he'd have the correct specs for checking sensors and such. In the long run you'll probably save money going to Nissan. I know that when I broke the ground wire to the MAF sensor, my car would barely start/run and would smoke badly and damn near choked me by the amount of unburned fuel being dumped out the exhaust pipe. A simple test of disconnecting the MAF sensor will reveal if there is a problem with the MAF ground or possibly the MAF itself. The car can run without the MAF plugged in. It will only rev to ~2500rpms, but it will run quite steady. This is how I figured out my problem.

Last week I replaced my spark plugs and forget to plug in one of the coil packs. The car started fine, but the engine was mildly stumbling/vibrating and didn't see seem to rev very happily. I popped the hood, slapped myself, and plugged the coil pack in. In a nutshell, the car will drive on 5 cylinders so I doubt a bad coil pack is the cause of your particular problem. A bad coil pack doesn't help matters, but I doubt it's the sole cause.


Dave

 

6 really old spark plugs and a bad coil pack, you got off easy for $400. Dealer would have charged $1000 or more for that tune up. That was about $130 - $150 in parts.

 

Yea...Sounds like you were definetly burning rich there since you said the smoke had a awful smell...if you were burning coolant then you would have a really sweet smell...which isnt the case...Hows the car doing now after the addition of new parts???

 

Well Bad news and a little good news.

The problem is still there. I drove it hard for an hour then parked it. I waited 10 mins exactly and the car started but immediately kept shuddering and smoking as usual. After that I put it in drive and drove it around the block, within 2 mins it went away and the car was back to normal. It always does this so I dont know what to do next. I guess ill just leave it the way it is for now and next week Ill have time to diagnoss it myself.

The good news is that the power is back and the maxima performs awesome. The tires chirp when WOT from a standstill. I guess the knock sensor and Sparks plugs were really shot because the car use to perform poorly, like it had 300k miles on it. Now its a different story.

As for the main problem, I give up for now. When I get time, Ill play around with the MAF but it does show symptoms of a bad coil pack. I dont think its the MAF because it only does this when car is warm and is restarted after 10 mins or so. My mechanic must have not tested each pack so I will have to.

BTW, the smell from the muffler is like that of a paint. It smells horrible.

 

Check your vacuum lines and the connection of the fuel injector harnesses. I had an injector harness that wasn't properly reconnected by a mechanic and it had some of those symptoms. It could also be the under hood harness for all 6 coil packs.

 

Sounds like a small head gasket leak to me... it runs like crap for a few minutes because you have a bunch of coolant sitting in your cylinder(s). After that blows out, you just have a little coolant and all it is doing is upping your compression slightly and burning off.

That is my guess though... I wouldn't be doing any WOT jumps with it like that.

Could be a cracked head too.

 

Oh yeah... burning coolant smells like a$$ and if it is burning coolant, it should condense like steam in your hand if you hold it in front of the exhaust pipe.

 

I really dont know what to do guys. Maybe next week I'll just take it to the Nissan and take a chance with them finding the problem. I just have to find a better dealer than the one in Great Neck, Queens. They seem to be always be packed so which dealer would you reccommend me taking it to?

Also the smoke that comes from the tailpipe is in a rhythm, like its huffs and puffs. I guess it is relation to the Idle speed. It does feel like one of the cylinder is out, which is why it shakes and puffs smoke. And after I drive for 2 mins, it somehow lights up and works.

If you guys think its a blown headgasket then how come the car doesnt show these symptoms when I leave it on, sitting and idling for a while. Wouldnt the coolant still be able to enter the engine and in turn blow off smoke? The symptoms the car shows only occur when the car is re-started so it is kinda strange. I am praying its the MAF or something electrical.

 

It died on me today and wouldnt start again. It started however after I pressed the gas pedal. The smoke from the tail pipe smells a lot similar to gas so would the problem be a clogged up or bad fuel injector?

I am going to put in the gas treatment bottle in today to see if it makes a difference. I have a feeling its either that or a bad coil pack.

 

bump.........