Exhaust smell

[Stephen]

Has anybody had a

problem with exhaust smell when you wind down the windows, if the windows are up no smell, if one

window opens, it near stinks you out,two windows down are fine,I have replaced rear hatch seal, have

two taillight gaskets on each light and my tailpipe is extended out a couple of extra inches and I know

for sure there are no holes in the underbody. I need to fix it, I'M GETTING LOOPY

[Jeffrey Richard]

I have the same problem with my 260Z

Stephen. Are all of the seals in your firewall ok? Do you know if your exhaust manifold is leaking?



The most likely place is the rear deck weatherstrip (did you change both?). After that, check the

tail light gaskets (you've done this), plugs in the decklid, interior decklid panel (must be sealed with a

plastic film like the door panels), floor plugs, holes in floor, and shift boots. Until you find the problem try

to limit your loopyness to a slight buzz. Is the buzz what they mean by "the feeling of driving a Z" or " I

have a Z addiction"?

[blue]

I am not sure if thisis on a 240z but if

so then  check the seal to the fuel sender area and also any fuel vapour recovery hoses.

[Zedguy]

Very common early Z problem.  We've

all had it.  I've been narrowing it down every year for the past 5.  Just when I think I've got it

licked...wham...it comes back.  I replaced my deck lid stripping about 4 years ago....but it was the repro

stuff from Victoria British.  Never fit right.  Gotta replace it again soon.  Firewall is a BIG problem, for

sure.  

Z is a Religion: it's a VERY holy car!  

 

[Stephen]

Changed all weatherstrip on all doors

hatch etc from Precision, brand new seal around shifter, new exhaust front to rear welded all seams no

clamps,new exhaust manifold gasket from Nissan,had manifold planed,replaced manifold flange gasket

twice in a year,second time put two in to get a good seal,do you think it is possible  my muffler is to

restrictive, it is supposed to be free flow,but Midas had a hard time finding a muffler to fit it properly so

maybe I didn't get what I asked for.I extended my tailpipe out about 3 extra inches as well,I was thinking

about trying a turndown on the tailpipe to see what happens,even though it would look like the" dogs

nuts" just as an experiment hoping airflow would take away the gasses,what do you think

[Jeffrey Richard]

Stephen did you check the plugs in

the bottom of the decklid and the interior decklid panel? This panel was never sealed at the factory and

should be sealed with a plastic film like the door panels. Pull the panel off and cut a piece of clear

plastic film (hardware store) and seal the hole. A thin bead of silicon around the opening should work

well then press the film into it. Reinstall the panel then drive to Moncton and pick me up. I need a ride in

a Z soon or I'm going to die.  I find myself sitting on the floor in my car shell making vroom-vroom

noises.

Another source could be a hole or separation in the seam between the rear quarter panel

and the deck lid floor. That section can be hard to see holes in. It wouldn't take much of a hole to suck

in fumes.

[blue]

I think Jeffrey hit them all.  Here is

more to flog a dead horse:


http://www.mdzclub.org/techtips/forgotten.html

http://http://www.zcar.com/forums/read.php?f=1&i=459304&t=459151#reply_459304

http://http://www.zcar.com/forums/read.php?f=1&i=418277&t=418197#reply_418277

http://http://www.zcar.com/forums/read.php?f=1&i=402044&t=401877#reply_402044

http://http://www.zcar.com/forums/read.php?f=1&i=400969&t=400724#reply_400969

http://http://www.zcar.com/forums/read.php?f=1&i=373750&t=372561#reply_373750

[Stephen]

Here is a reply I got

from ZONC on exhaust smell.


Hi Stephen, Doc here, there is

one area that you have not covered and that is inside the hatch above the lock/latch mechanism.  I have

found that a good grade of plastic can serve well to seal this area when glued in place.  Have you

checked the seal of the hatch to the body?  How are the rear inner quarter panels at the bottoms?  On

some models there is a drain at the bottom and the negative pressure at the rear of the car can cause

the gasses to come into the cabin there also.
  One other thing  that comes to mind is how is the

engine running?  Is the tune-up recent?  What does the exhaust smell like?  If it smells rich then the EFI

system is in need of recalibration, and quite possibly the cause of the smell.  Rotten egg smell is too

rich and another smell is too lean.
  Please get back to me... Go to docs-auto.com for further help and

access the 911 information.
I hope that this helps you...
Are you a ZONC Member?  JOIN ZONC!  Z

Owners of Northern California!  Ask me How!

ZDOC OUT :^)

[Jeffrey Richard]

Is he refering to inside the hatch above

the lock/latch needing plastic as the inner hatch panel? If so we did cover that. If not get more info from

him we may need it.

[Stephen]

Went to Canadian Tire,

bought some plastic that you use for over tablecloths for special occasions,and I urethaned it in place on

the rear hatch under the interior panel and then went out and drove the snot out of my Z around town and

PRESTO smell is gone. Thanks to all who replied to my posting it was much appreciated.( ps the guy in

the new 2004 Corvette smoked me before he got out of first gear on the blocks), but hey anybody can

buy a vette they are available everywhere,can't say that about a Z,

Z owners have style!!!

[blue]

Jeffrey nailed it!  Pat his back!



I'm glad you fixed the problem.

btw if your Z had the turbo motor and an upgraded

turbocharger (16psi-20psi), the corvette would have had a tougher time ( 240ZXT = 2,300 lbs with 300 to

400HP at rear wheels)

[zZoomZz (Peter)]

Thought I'd resurrect this post, since a couple people besides me have this problem......

[Jeffrey Richard]

I have the dreaded exhaust smell and just haven't fixed it yet. I'm sure mine is coming from the deck lid panel. I have some clear plastic and sealant and will try it soon.

[zZoomZz (Peter)]

Yes it's really bad in my car. I always thought the fumes got sucked in through the open window, but I understand now that it's because vacuum is created in the interior rear when the window is opened.
I'll be buying body sealant this weekend. The various fixes may warrant a couple pics and instructions.

[Jeffrey Richard]

Peter I was thinking just that. Lets make a tech tip with pictures documenting the various potential problem points.