So I have a 1995 Maxima. It's been driving fairly well for awhile now. Then suddenly today I see a lot of white smoke coming out of my exhaust. I pulled the spark plugs to check further and the 3 front ones are like white on the tips while the 3 back ones are still like a brownish color. So from what I can gather from it, its almost like its burning coolant or something which would be from a BHG. But I have never overheated the engine or anything so i'm confused as to how this is possible. Any thoughts?

p.s. I drove it in the morning to take my girlfriend to work and came home, no problem. 6 hours later, went to pick her up and it started doing this. Also on the way home it stalled like everytime I came to a stop but was able to start back up.

 

The plugs should be clean, light tan to white color on the tips. The brown plugs in the rear indicate a rich condition on that bank. If the HG was blown and coolant was entering the combustion chamber, your spark plugs would look brand new. (think steam cleaned)

Where are you located? The weather, specifically the extremely low temperatures across the country play a big part in what your exhaust gases look like.

Moisture is a by product of combustion and is visible in the exhaust gases, more so when it's very cold outside.

 

I'm in south florida. we got hit with a cold front but its never acted like this before in this weather. and it still doesn't make sense how it can run fine in the morning then be so messed up a few hours later. especially the stalling. its never stalled before.

 

It's hard to blow a HG on the VQ. Your stalling might be an issue, but I doubt it's a HG failure. What your seeing it the moisture in your exhaust gasses, elevated and more visible in the cooler air temps.

Post a video so we can have a look

 

too dark to do a video atm unfortunately. now I know in colder weather you can see the exhaust gases more, but its usually just from the pipe and disappears in that same area. you can actually see this rising and surrounding the car if at a stop. and I first noticed it because I could see some of it coming from the engine bay when I was at a stop.

 

if you have a blown HG, the pistons etc usually look stream cleaned. spark plugs with white on them could mean its burning coolant

you can get test kits for BHG, might be worth doing one. also if you run the engine with the rad cap off, there will most likely be air bubbles from combustion gas if the HG is gone

 

I can get the gasket and head bolts for decent price, and I can do the job myself, just looks like a PITA and probly a couple days worth of it. i'm just trying to be sure that is the problem before diving into that kind of project for no reason.

 

Wouldnt a blown head gasket result in having coolant in the spark plug tubes, along with the oil being milky due to coolant mixed in? Or are these symptoms that dont always happen?

 

I asked my brother that too, he's really good with cars and has helped me work on mine in the past. if I remember right, he said it can actually be enough just to leak into the combustion chamber but not actually into the oil. now my memory isn't all that good but I think that's what he said lol

 

not always. on my Toyota Crown, the HG was starting to go. oil was clean, spark plugs were fine, no white smoke, no regular symptoms. only thing was when i went on the highway past 150km/h around 4000+rpm, the coolant reservoir would flood out coolant. got a HG test kit, passed it at idle but if i tested the coolant at 4000rpm, sure enough it failed. replaced the headgasket, fixed it

the HG on my Hilux is completely gone. 2 cylinders probably have no compression, white smoke flies out, coolant is milky, and after cranking it for 5 seconds the rad goes under full pressure and the coolant reservoir floods from all the combustion gas going straight to the rad. thats an extreme blown headgasket lol

is the car low on coolant at all? if the coolants been constantly going down it could mean BHG

 

Coolant levels still seem fine. But then again I only drove it for a short amount of time after I noticed it.

 

ok so I got a video. isn't long but I think you'll get the idea. now keep in mind that it was like 80 degrees outside too so weather shouldn't be causing this. also when I tried to drive it some today just to get a feel of whats happening, there is some serious sluggishness from it. also the higher the rpms the more and thicker the smoke.

http://www.youtube.com/watch?v=GUcgn...ature=youtu.be

 

looks like HG to me. try smelling the white exhaust, if it smells sweet its coolant

 

yup, so its confirmed then, BHG. So then the next thing I need to find out is if anyone from the forums lives in the south florida area and wants to come help me change it. I know buying a new engine is probly easiest but im a little strapped for cash lol. need to have it done ASAP too, this car is our only mode of transportation right now.

 

Dude that's not a blown head gasket. If it was burning coolant it would be puffs of white smoke and would linger in the air. Your oil would mix with the coolant. You have a missfire and that's un burned fuel. Look jt up on youtube gm blown head gaskets. I myself amd a coulpe of friends had gm's and we experienced blown heads. Like one of the members posted its hard to blow the head on a vq

 

It really does sound like its missing.


Although watching that 15 second video multiple times isn't really ideal. Maybe shoot some more video for longer. Include the engine running too.


How many miles are on it?


I would check the coils too. You can either use a meter and check the resistance or, pull the harness plugs one at a time to isolate which cylinder is not firing.


Yet another approach is to check the injectors. I was installing new injectors once upon a time and managed to tear the O-ring. Same issue. White smoke and rough idle. Too much fuel.


Have you pulled the codes?

 

I actually had a q45 that ha d a bad injector the stuck open smoked up my whole block. Its apparent though the op never owned a gm car. Lol.

 

So I would look at a video about gm blown hg for a nissan? Strike one. And it was already mentioned from another member that he had a bad hg before too on another car and the oil was clean so it doesn't always mix. Strike two. And as for the stuck open injector, for it to cause the symptoms on all 3 of my front plugs at the same time is highly unlikely. Strike three. Next time just dot bother to post. Would save us all a great deal of time

 

but again the best way to confirm a bad HG is a combustion gas test kit. my Crown had no milky oil etc because i caught the bad HG as early as you can pretty much. buddy drove my Hilux for a while with a blown HG to the point that it overheated, that thing had milky oil, fecked the spark plugs, low cylinder compression, etc