white smoke, and oil smells like gas

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wickedpelf
Posts: 750
Joined: Mon Feb 24, 2003 11:08 am
Car: 1991 240sx with super hicas

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ok heres my problem, a couple days ago my car starts spewing out white smoke, all the time, it also has a hard time starting, i have plenty of coolant, but i checked the oil and it smells like gas... headgaskit, injecter stuck at full blast or what?


Blown240sx
Posts: 1963
Joined: Thu Apr 21, 2005 3:20 pm
Car: 1996 240sx

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Head Gasket you would notice major power loss since your losing compressionCould be Piston Ring which you would also notice some power lossCould be bad turbo but this wouldnt make your oil smell like gasCould be over loading on fuel also but the car would run like *** and probably foul out the plug on that cylinder.

daraleekmyballs
Posts: 61
Joined: Sat Aug 20, 2005 6:56 pm
Car: 91 240sx

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if its white smoke and none other, then you should start approaching the fact you may have a blown head gasket. check for white film under the oil filler cap or you can dump your oil out and inspect it to see if you have water/coolant in there.

nzmoman
Posts: 2302
Joined: Mon May 22, 2006 2:27 pm
Car: 240sx 2 of em' and always lookin for more

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When is the last time you checked your plugs? is it thick smoke and have you noticed your oil level decreasing significantly? Youll know if it is the turbo if you pull off the exhaust mani. If you see stagnant oil in the ports then you may want to invest in some studs and gaskets. IF you dont look into the turbo elbow and see if there is some there, this is a simple way to check your turbo out, but you also said the thing about hard starting, which will be related to either your spark plugs or your lack of proper compression, if the starting gets worse youll be able to tell then also.

my coupe with a blacktop has the same deal...the motor sat for a while (approx 3 months after running flawlessly) I did the swap and had to change out the ignitor. it did not have any issues before, but after the startup it was doing the same thing... at first there was power loss, I thought there was missing boost, and suspected the head gasket but one of the silicon hoses was cut open and I had a leak. I also was confused because I had never heard of a headgasket going bad while the car sat. I never lost coolant and after replacing the pressure line the car still smokes but it has never overheated. It makes and maintains boost. no problems driving but I dont drive it much yet. And the smoke is not very thick and the amount decreases after the car is warmed up. Oil in the valve cover looks good and the oil pan oil is good. I dont really get on it yet cause I dont know what that is and the car hasnt been tuned yet, that happens this weekend.

also a friend suggested that I check my maf connector and the sensor itself to see if they collected debris. I thought Id throw that out because I will do anything to keep from having to replace the headgasket.I tried to run codes on my ecu just to check and it didnt throw anything, not even a 55 so I may be checking into that during my tuning process.

wickedpelf
Posts: 750
Joined: Mon Feb 24, 2003 11:08 am
Car: 1991 240sx with super hicas

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well when i checked the oil...the level had risen...since im up at school my dad took the car to a mechanic thats worked on the car before...but i wanted to get the dude that put the motor in to work on it...but he wont be able to get a spot in a garage until aug 1st...

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da40
Posts: 900
Joined: Thu Mar 02, 2006 12:07 pm
Car: 1995 SE 240sx

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sounds like a head gasket to me ...either its going or its gone man

kickertu
Posts: 226
Joined: Tue Aug 27, 2002 5:16 am

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actually, i bet AGAINST a blown head gasket.

its a bad injector o ring if antying..

turn the key to the on position, let it sit for about 5 sec, then turn it off,

turn it back on, and off for about 30 sec..

then pull your plugs and see what cyl has a huge puddle of gas in it.

i wouldnt drive it aymore till you figure that out.. its either that, or you have an injector that is stuck open. and it will just fire all the time.

i had a bad injector do the same exact ****, and it ended up bending an sr rod because it filled with gas and huydrolocked.

Blown240sx
Posts: 1963
Joined: Thu Apr 21, 2005 3:20 pm
Car: 1996 240sx

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Actually before you do ANYTHING you need to do a compression test, then a leak down test. If your HG is blown youll know it. If its an piston ring which I think it is youll see it on 1 of the cylinders when you preform the compression test.

Also your oil level going up shows that your probably getting fuel mixed with the gas.

Do a compression test first, Also did you ever pull theplugs to see if they are fouled?

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da40
Posts: 900
Joined: Thu Mar 02, 2006 12:07 pm
Car: 1995 SE 240sx

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i agree with Blown240sx might want to do that first

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Rapeacivic
Posts: 57
Joined: Tue Dec 06, 2005 4:23 am
Car: 1993 Turbo Scepter(Sold) 1996 S14

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nzmoman wrote:my coupe with a blacktop has the same deal...the motor sat for a while (approx 3 months after running flawlessly) I did the swap and had to change out the ignitor. it did not have any issues before, but after the startup it was doing the same thing... at first there was power loss, I thought there was missing boost, and suspected the head gasket but one of the silicon hoses was cut open and I had a leak. I also was confused because I had never heard of a headgasket going bad while the car sat. I never lost coolant and after replacing the pressure line the car still smokes but it has never overheated. It makes and maintains boost. no problems driving but I dont drive it much yet. And the smoke is not very thick and the amount decreases after the car is warmed up. Oil in the valve cover looks good and the oil pan oil is good. I dont really get on it yet cause I dont know what that is and the car hasnt been tuned yet, that happens this weekend.

also a friend suggested that I check my maf connector and the sensor itself to see if they collected debris. I thought Id throw that out because I will do anything to keep from having to replace the headgasket.I tried to run codes on my ecu just to check and it didnt throw anything, not even a 55 so I may be checking into that during my tuning process.
I have the same problem. Before I bought my S14 it had sat for a year due to an electrical problem. I fixed the problem it had and now when I start the car it blows white smoke out of the exhaust until the engine warms up a little. I´m hoping it´s not the headgasket but I am not sure. I have checked the oil and the oil is fine. Also feels as though the car is not running it´s full potientional.

I am probably just going to go ahead and rebuild the blacktop anyway cause I do not trust what the previous owner did to it.

nzmoman
Posts: 2302
Joined: Mon May 22, 2006 2:27 pm
Car: 240sx 2 of em' and always lookin for more

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Rapeacivic wrote:
I have the same problem. Before I bought my S14 it had sat for a year due to an electrical problem. I fixed the problem it had and now when I start the car it blows white smoke out of the exhaust until the engine warms up a little. I´m hoping it´s not the headgasket but I am not sure. I have checked the oil and the oil is fine. Also feels as though the car is not running it´s full potientional.
Okay, she was tuned today and runs like a dream. the powersteering rack has a bad leak, but mechanically everything is fine.

Before when i was telling you that I had to replace the ignitor chip, I did a lot of cranking and running the fuel pump. well that and my screwy spark plugs did a poor job of pulling that fuel out. according to my gearhead buddy and the person I like to call with major issues, I also had a little bit of air in my cooling system, but we contribute most of the symptoms to a computer that was acting wacky.

After tuning her up all I need to do know is change my oil and replace the spark plugs There is no smoke at all anymore. It went from thin white smoke to thin black smoke to no smoke at all at any throttle position with a cold motor and hot motor. my oil level has not changed and my coolant level remains full. She pulls like a mother, and barks her 15s into third gear at about .7 bar! ~8 to 9 psi

again I agree with the compression test, but dont go tearing your heads off prematurely until you know that is what you need to do unless the gasket was in your plans already, i am blessed to not have to, and there are a lot of shops who will tell you that you have a faulty hg because they dont know and cant always tell either, plus it can cost quite a bit for them to do it.

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Rapeacivic
Posts: 57
Joined: Tue Dec 06, 2005 4:23 am
Car: 1993 Turbo Scepter(Sold) 1996 S14

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nzmoman wrote:
Okay, she was tuned today and runs like a dream. the powersteering rack has a bad leak, but mechanically everything is fine.Before when i was telling you that I had to replace the ignitor chip, I did a lot of cranking and running the fuel pump. well that and my screwy spark plugs did a poor job of pulling that fuel out. according to my gearhead buddy and the person I like to call with major issues, I also had a little bit of air in my cooling system, but we contribute most of the symptoms to a computer that was acting wacky. After tuning her up all I need to do know is change my oil and replace the spark plugs There is no smoke at all anymore. It went from thin white smoke to thin black smoke to no smoke at all at any throttle position with a cold motor and hot motor. my oil level has not changed and my coolant level remains full. She pulls like a mother, and barks her 15s into third gear at about .7 bar! ~8 to 9 psiagain I agree with the compression test, but dont go tearing your heads off prematurely until you know that is what you need to do unless the gasket was in your plans already, i am blessed to not have to, and there are a lot of shops who will tell you that you have a faulty hg because they dont know and cant always tell either, plus it can cost quite a bit for them to do it.
Thanks bro for the info. I had already planned on rebuilding the engine because the guy I bought the car from had the engine rebuilt 2 years ago by a shop and I think they did a ****ty job. Rebuilding the engine is not a problem for me as I am a certified mechanic. But this problem has had me stumped. I do believe that the engine has lost compression. As soon as I can find the time and money I will begin the rebuild.

dave87rx7
Posts: 7
Joined: Fri Mar 11, 2011 8:26 pm
Car: 1989 240sx with red top sr20

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what was the reason? my car is doing the same thing but thick smoke with a heavy gas smell......

daneo
Posts: 5
Joined: Mon Apr 05, 2010 7:18 pm

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I have similar symptoms. In my '90 300zx

I did an injector swap this weekend. Idled it in the garage for 10 minutes, no issues. Did a mile loop. No issues. When I started the car, it was almost instant-on. You'd just think about the ignition and the puppy would fire up.

I was driving home today at about 50mph and i spied white wispy/billowy (not opaque) smoke in my rear view. I didn't notice any sounds or vibrations from the engine. Turned off the road ASAP. Engine died when I put in the clutch to downshift, restarted when i let the clutch out. Rolled to a stop some 200ft later. I can't remember if I shut off the engine at this stop, or if it died. There was still a little bit of "smoke" (more like vapor or steam) coming out the right exhaust when I went around back. I quick went down for a smell. Not a hint of antifreeze smell. It smelled heavily of fuel. A few seconds later I could see the wavvy lines associated with evaporating fuel coming out the exhaust tip. I pulled the relay for the fuel pump to ensure that if there was a runaway injector, it wouldn't have pressure to work with.

Got towed home (not far... but bless AAA). I let it sit for a couple hours and read a few forums. I checked the oil and it smells a bit of fuel. The level is above the hash marks. It was last changed by the nissan folks, so I hope they're capable of not overfilling. It wasn't putting out smoke before the injector swap, anyhow.

So, I have similar symptoms so I thought I'd ask also if you can elaborate on what you changed on your "tune up" to get things working. I know this thread is a couple years old, but hey. Why start a new one for the same symptoms.

I'm thinking it could be a stuck-open injector. A pinched o-ring is possible but I was SUPER careful lubing those suckers up and putting them in. Also, it was a sudden issue that only manifested after ~10 miles.

Also, everyone hope with me that nothing got bent. :ohno:

Other thoughts welcome. I suppose an oil change at the very least will be needed. I'm leaving it for the night to let my fear/sadness/anger/stress subside so I don't get grabby.


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