Fumes - the ultimate battle

[alsil]

Ok guys, I (as always) have a weird issue.

 

I have fumes in my car.

So I tried some of the common solutions to this:

- taillight gaskets (new)

- hatch gasket (new)

- door weatherstripping (new)

- PCV valve

 

Still, I have fumes. what is weird, is before I had had them whether the window was down or not. Now I just have them when the window is down.

I don't get that. Obviously the fumes are coming in through the window, right? I am kind of wondering where they are originating from.......

Any ideas?

 

Thanks

Al

[pparaska]

Al, the fumes are traveling backwards from the exhaust pipe tip into the window. This is common for a old Z - the aerodynamics are pretty hosed up. Some people put long exhaust tips on the car to help with this, but I think it looks silly sticking out 6" past the bumper. I hear that a rear spoiler actually helps.

 

Oh, I always found that putting BOTH windows down helped. It seemed that if the pass window was closed but my driver's window was down, the fumes were worse than with both down.

[fl327]

my buddy runs a pipe out the side of the rear lower valance, and he says it stopped the stank really well, except when hes at a light or stopped. running a really long exhaust works somewhat.

ive also seen people run turndowns, but i honestly think it looks really retarded to have a turn down tip coming out the back of the car. im going to run two mufflers diagonally towards the left stacked under where it does stock, but style is my main goal, and yes, with both windows down it helps.

[74_5.0L_Z]

Another place to check is the expansion tank behind the passenger side rear wheel well. A bad hose will cause gas vapors or gasoline to get into the car. Those hoses are often badly rotted.

[Guest scca]

did you replace the round little gaskets in the hatch at the back? about 1.5" round plugs...

 

what happens when one window is down is it creates a vacuum and sucks from the back.

i've always thought it sucks fumes THRU the hatch rear area - not bringing it up to the window. but i could be wrong.

 

with both windows down enough air flows to not notice, with both up no vacuum to suck thru.

 

with one down usually the problem is the rear hatch. i have seen the tiny little rubbers with cracks in them allow the fumes into the car. i've replaced these more than once and it has solved the problem... most people seem to forget these 2 bits- they seem so small but a tiny hole the exhaust fumes will find...

 

you also want the exh pipe to at least go 1" past the bottom of the bumper lip. doesnt have to go past the bumper edge but enough so that the majority of the fumes dont catch on the bumper lip and curl up into the hatch area.

[Guest Anonymous]

That problem has plagued me ever since I've had my Z also. I have almost passed out one time leaving the gym after a hard workout and huffing those fumes while breathing hard... not good. I think my lungs are permanently damaged... The 2 window down thing works pretty well but the fumes still get in there, believe me. Ever notice that every old Z smells the same, straight up exhaust fumes! With both windows up it is almost non existent but one down certainly doesn't work. My lungs begin to hurt after just a coulpe of minutes in the little tyke, I can only imagine it's going to get worse when I double the cubes and more than double the power... we will all probably die from carbon monoxide poisoning, but then again we all have to die of something!!!

[Guest Tim78zt]

OMG, Long, I think we are on to something here of MUCH larger proportions than we realize!!! This could actually explain why most Z owners seem a little wacky, and our cars tend to be involved in more accidents than Porsches and Corvettes combined!! I think if cigarette smokers can win their battle with the tobacco companies, I am beginning to smell class-action fumes. Mr.Nissan, any comment?

(I understand if this gets moved to the non-tech board or deleted all together!!)

 

Tim78zt

[fl327]

hey went for a ride in my buddies car with the exhause that comes out on the rear driver side of his car, below the side marker below the bumper he runs a rectangle pipe and two glasspackes to quiet it on a l6, he has no fumes while driving, but some while sitting still because the exhaust gets the chance to slowly get in thru the window, but it is non existant while driving, im gonna go to a similar route and run dual mufflers diagonally left one out of

the stock spot, die grind it a little bigger so i can get more angle on it, and another below it angled same way a little bit right, hope it works, if it does imma do the running man dance.