Jump to content


New Exhaust Fume Fix

  • Please log in to reply
8 replies to this topic

#1 logr



  • Members
  • PipPipPipPip
  • 196 posts
  • LocationNorth Idaho

Posted 10 May 2012 - 04:31 PM

I searched but couldn't find this anywhere so thought I would pass it on.
I have been fighting exhaust in the cabin on my 240 but only when driving with a window down. It has been driving me crazy and from my searching, it is common and usually accepted as part of owning a Z.
I have an SR that is fuel injected and clean burning, getting over 30mpg.
The exhaust goes to the stock location.
The hatch seal is new.
The tail lights are sealed.
All holes are sealed.
It still smelled very badly with a window down UNTIL

I found the rear frame rail that runs side ways under the tail lights was not sealed underneath the car anymore. It is still sealed into the cabin from the top but after much checking I found that there is a hole on each end(rearmost part beside the tail lights and inside the side panels but all the way at the rear bottom)of the rail. You can not see it but you can feel it on both sides. I stuffed some plastic sheeting in both ends to seal it off. This is the same tube that the rear tie downs are bolted into. I blew air into one of the tie down holes and felt it come out the bottom of the car and out of both ends inside the car. That is what convinced me to close off the ends. It solved the exhaust smell completely.


Moderators, I did not know where to post this so feel free to move it or delete it if I am the only one that did not know this.

It's not the length of your crank that counts, it's the power of your stroke.

#2 z240


    Junior Member

  • Members
  • PipPipPipPip
  • 377 posts
  • LocationCalgary AB, Canada

Posted 11 May 2012 - 07:03 AM

Excellent find! I do not remember anyone reporting this so far.

I found these same holes/gaps when stripping the under belly of my 73 this winter. Looks like the seam sealer that was applied in this area ran a little short..... Both sides were remarkably similar in the way the adjacent sealer bead just stopped a bit short..... I took pictures, I'll have to post them.

I remember a thread a few years ago on CZCC about a frustrated guy that used a smoke machine on the outside and a sealed interior wiht a vacuum attached to watch where smoked flowed into the cabin. He mentioned the same "It was coming through the dang seams!!!" observation.

#3 Leon


    Tremendous grasp of the obvious.

  • Donating Members
  • PipPipPipPipPipPipPip
  • 2317 posts
  • LocationSan Bruno, CA

Posted 11 May 2012 - 07:56 AM

Excellent, I need to check this out. I'm tired of inhaling fumes when I want the window down.




  • Members
  • PipPipPipPipPipPip
  • 1046 posts
  • LocationLas Vegas NV

Posted 12 May 2012 - 06:44 AM

Wonder if its the same for the 280's... I'll have to check thanx!
1979 280ZX "SKITTLE" (lime green, stock color) SOLD
1976 280Z "Skittle 2.0" LT1, T5, Turbo rims, and more junk.
Posted Image

#5 logr



  • Members
  • PipPipPipPip
  • 196 posts
  • LocationNorth Idaho

Posted 12 May 2012 - 07:57 AM

It is an easy check. Pull a rear tie down bolt out and shoot in compressed air. If it hits your feet, there is a problem. The only question then is if the rail ends are open inside the car.

Glad this is a help.

Edited by logr, 12 May 2012 - 07:58 AM.

It's not the length of your crank that counts, it's the power of your stroke.

#6 Six_Shooter



  • Members
  • PipPipPipPipPipPip
  • 1467 posts
  • LocationOntario, Canada

Posted 12 May 2012 - 02:29 PM

I picture or more would help to identify the area.

I'm not sure what you mean by "rear tie downs," so I'm not sure I understand where to look.

Funny how "there's nothing new in the world of Z-cars", and yet, here is something new. ;)

Edited by Six_Shooter, 12 May 2012 - 02:31 PM.

Z: 152391 Project Thread
Typhony: Project Thread

My rear view mirror doesn't have a zoom feature.

#7 logr



  • Members
  • PipPipPipPip
  • 196 posts
  • LocationNorth Idaho

Posted 14 May 2012 - 12:14 PM

There are either bolts, bolt holes or tie downs at the back of the floor, right up against the tail light cover. If there are holes, plug them to stop another leak. There are 2 bolts on each side of center about a foot out.

It's not the length of your crank that counts, it's the power of your stroke.

#8 Mike kZ

Mike kZ

    Super Moderator

  • Super Moderators
  • 2521 posts
  • LocationAtlanta GA

Posted 15 May 2012 - 04:43 AM

Moved to FAQ > Troubleshooting

#9 wrcbonk


    Junior Member

  • Members
  • PipPipPipPip
  • 193 posts
  • LocationRoseville, CA

Posted 15 May 2012 - 07:13 AM

Great work Logr, have the same issue with my efi 240, can't wait to see if that fixes my issue.


Series 1 RB25DET swap rolling under its own power in my S30

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users