# Fumes in passenger compartment



## jcook (Nov 23, 2005)

I have a 91 Nissan that gas or exhaust smells come in when the heater is turned on. Does anyone have any idea where this might be coming from because I have looked under the hood and under the car and don't see anything obvious.


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## kremlon (Sep 9, 2005)

jcook said:


> I have a 91 Nissan that gas or exhaust smells come in when the heater is turned on. Does anyone have any idea where this might be coming from because I have looked under the hood and under the car and don't see anything obvious.


mine does the same thing sometimes... but since i have no clue what causes this... it probably doesn;t help you. But hey... at least you know your not alone.


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## phin (Jul 20, 2005)

jcook said:


> I have a 91 Nissan that gas or exhaust smells come in when the heater is turned on. Does anyone have any idea where this might be coming from because I have looked under the hood and under the car and don't see anything obvious.


I too have a 91 stanza. I'VE had the same problem for years now!!!;i have
been told my injectors are leaking and need to be replaced.I have not
done so yet as the injectors are very expensive.I got somebody to change
the seals of the injectors,but it did not solve the problem.Don't know if
the guy really changed the seals?.My car works fine otherwise except
on cold start where i have to feather the accelerator pedal.I hope this
helps and if you solve this problem let me know.I forgot to say i also change 
the gasket on the exhaust manifold. Maybe that is your problem as it is
not so obvious. Good luck


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## Macc (Jul 4, 2005)

The smell should be obvious whether it is gas or exhaust. The likely reason you smell it when the heat is on is that either your vent door is out of adjustment or there is some debris (dirt etc.) holding it slightly open. If it is an exhaust smell then maybe a bad gasket, crack in the manifold, or part of the EGR is open. If it is a gas smell then your problem is likely either a leaky fuel hose or a leaking fuel injector. What you need to do is repeatedly turn the key from off to on several times without starting the engine. Each time you do this you will hear the fuel pump cycle on for a few seconds and build up some fuel pressure. Then, after several times, go under the hood and visually inspect and smell the rubber fuel lines and fuel injectors. The advantage of checking it this way is that you do not have the engine heat evaporating any leaking gas rapidly. Really check everything up close and make sure hose clamps are good and tight. I once had a bad hose going to the fuel filter that had a leak. It really wasn't enough to drip but the hose was wet like a sponge. At first glance the hose looked alright, but when I bent it a little bit it had lots of little cracks in it (like dry rotted). On the other hand, your problem could also be one or more of the fuel injectors. The part of the injector that goes into the fuel rail has an o-ring and a rubber insulator. The part that goes into the engine just has an insulator. A leak in this area could either be the seals or the injector body itself. Auto stores sell replacements (3 pieces for each injector) for about $5 per each injector. But if the problem is coming from the injector area do not necessarily assume it is the seals. It could be the injector body itself that is leaking. If that is the case, then your only option is to replace the injector. Those run about $100 each. If it is a gas smell and you cannot locate anything under the hood then check back by the tank. Sniff around by the rear driver side tire and see if you smell anything. There are several rubber lines back there that could be bad and the fumes can work their way into the interior (fuel pump lines in and out, vent line, evaporative emission line, and fuel filler tube). Note; any gas fumes in the interior will be more noticeable when the heat is on as opposed to the airconditioner (or cooler air). Good Luck, post back what you find!


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## RocketRodent (Jun 21, 2004)

If the smell is exhaust related. You may want to check you downpipe. The stock flex joint will sometimes completely deteriate. But when this happens the Stanza sounds really loud. I have the same issue as everyone else and this seems to be the only logical answer.


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## focker (Dec 20, 2005)

I had gas fume smell in my 1990 Stanza. I bought new fuel injectors and changed them. The smell is gone.

bought them at a Canadian Nissan dealership @ $170/each


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## phin (Jul 20, 2005)

Did u have to buy a special color code for your car?.The reason i'm asking
is that i was told i had buy a special color for my 91 stanza.I took my injectors
out and could not find any color mark on it.The only thing of color is the
plastic electrical terminal which is red.
ONE other thing i 've noticed that the plastic or ceramic cap that covers
the end of one injector is cracked;does anyone know the importance
of this cap bec that injector still works?.
QUOTE=focker]I had gas fume smell in my 1990 Stanza. I bought new fuel injectors and changed them. The smell is gone.

bought them at a Canadian Nissan dealership @ $170/each[/QUOTE]


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## isb360 (Apr 6, 2005)

Going off on a tangent here...if the injectors are color coded, my guess is that they are for different applications, and probably are designed to give different nominal fuel flows for (potentially) higher horsepower vehicles. This leads me to my question: if this is the case, could slightly "larger" injectors be put in to deliver more fuel? I would think that within reason, the engine management computer would be able to compensate for the extra fuel and deliver a bit more power.

Any thoughts?

p.s. I have a Dodge Ram Cummins 24v diesel with "100hp" injectors and the computer compensates for increased number of orifices and you get a net +100hp gain at the flywheel, no questions asked.


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## columbus13 (Jun 23, 2009)

I have a 2008 sentra. This morning, I noticed some smell-less white thin fumes from the AC vents while driving to work. The fan was at the lowest speed and AC was set to coldest with recirculation ON. It was relatively humid and was about a 75 F outside. I tried to smell the fumes and there was no odour at all.

Since this is my first car, I am not very experienced in car related issues. Can anyone please tell if this is a common phenomenon (assuming that it was just condensed water vapor) or can there be a possible problem with the HVAC system.

(Soon after noticing the vapors, I stopped over to check under the hood. I couldn't notice any conspicuous problems there)


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## jerseymike68 (Sep 15, 2009)

Thanks for these information


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## nano49 (Oct 6, 2009)

Hello evryone, the gas smell is not nescesarily fuel injector replacement, I have a 92 stanza and had a gas smell for months, car was running fine so what i did was replace the injector's gaskets/O rings and problem solved 59 cent each at autozone.
if it is exaust check your nuts!! lol check manifold and catalytic covertor nuts make sure they are tight, also like some1 said above keep and eye on your flex pipe


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## nano49 (Oct 6, 2009)

columbus13 said:


> I have a 2008 sentra. This morning, I noticed some smell-less white thin fumes from the AC vents while driving to work. The fan was at the lowest speed and AC was set to coldest with recirculation ON. It was relatively humid and was about a 75 F outside. I tried to smell the fumes and there was no odour at all.
> 
> Since this is my first car, I am not very experienced in car related issues. Can anyone please tell if this is a common phenomenon (assuming that it was just condensed water vapor) or can there be a possible problem with the HVAC system.
> 
> (Soon after noticing the vapors, I stopped over to check under the hood. I couldn't notice any conspicuous problems there)


Columbus13........... Don't worry mate it is the humity in the air, I live in Florida and when it rains and its hot and turn the A/C on vapor comes out of my vents for a few second and then disapears:givebeer:


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