First drive in the z in 25 years.....impressions.

[Patcon]

10 hours ago, Captain Obvious said:

Oh yeah there are. Maybe the earlier years are worse, but the 280's are not immune.

On the other hand, maybe they're just not as bad because of the fuel injection being better than carbs?    

I suspect the holes they added in the rear pan also help with air flow at the back of the car

[takayuki]

I have zero issues with fumes on cars. I did a complete resto of the car so I can't pinpoint what fixed the issue. Replacing all the gasket, seals and grommets is what i did anyways. I shaved the antenna hole so that also eliminated an area for leaks. i also discovered a tube from the power  antenna going down to a drain hole at the very bottom of the left rear wheel well by the muffler. Since I no longer have an antenna, i plugged that hole with a grommet. My car is a early 260z.

[70 Fairlady Z]

My 1980 Fairlady Z had fumes, my 1970 Faorlady Z has zero fuhnes.

[dutchzcarguy]

if you still have fumes open hatch lay a piece of paper on the rubber seal..  close the hatch and if you can easely pull the paper out it does not close well and leaks. put it back in and close hatch, move the paper around and look for more leaks. Adjust the hatch or maybe you just need a new rubber seal there..  

[Namerow]

On 11/23/2017 at 6:47 AM, madkaw said:

Also make sure the hatch inner vinyl panel is in place and sealed . Exhaust will suck in from there


Sent from my iPhone using Classic Zcar Club mobile

Ditto on this comment, in case you missed it.  This panel (plastic, not vinyl) tends to warp, opening up some pretty wide gaps along seams that are supposed to be sealed shut.  It's also held in place by the usual push-pin plastic rivets and I've noticed from photos that some of these are often missing from owners' cars.  Once gaps appear between the plastic panel and the inside sheet metal of the hatch, the factory's cabin-to-outside airflow scheme can be bypassed (including the one-way flaps located inside the ducts) and exhaust fumes can enter the cabin by entering the hatch cavity and then leaking past the plastic trim panel.  In the factory scheme, the air extractor pathway is supposed to be the only route for air to flow from the hatch area of the cabin to the outside, and that pathway is supposed to be sealed off from the interior of the hatch.

[tzagi1]

Meanwhile at the bat cave....I replaced the muffler, put on a tip that extends 6 inches behind the body, fixed an exhaust leak between the muffler and the pipe and the smell is almost gone, now I can smell it but only under hard acceleration....back to the drawing board. (possibly more exhaust leaks?)

[grannyknot]

Do you have a rear spoiler?  It is the only thing I have found that gets rid of the problem for good and I sealed up both of my Z's tight as drum.

[Namerow]

There's one thing that still puzzles me in all of this:  I owned my first Z (a 1972) from 1977 until 1981 and logged about 40 thousand miles of driving with it -- much of that at freeway speeds on regular trips between Toronto and Montreal (~ 300 miles, each way).  I do not recall ever smelling exhaust fumes inside the car during those drives, nor feeling any effects while driving (which I surely would have over 4 hours of driving).  The car was bone-stock and all-original (e.g. no weatherstrip replacement, no new taillight seals, no rear or front spoiler spoiler, no special exhaust tip, no replacement grommets, no caulking -- nothing).  So I'm reasonably comfortable in saying that there was nothing in the design of the later-version cars (i.e. with the cabin air extractor vents located on the sail panels) that led to exhaust fumes being sucked into the cabin.  Not, at least, when everything was left in original configuration and all of the grommets and seals and weatherstripping were in good shape and and the body seams were in proper alignment.  In fact, I don't think that even the addition of an aftermarket exhaust system changed that, because I don't recall reading any warnings or tales of woe, back in the day, about exhaust fume issues showing up after an Abarth/ANSA/Stebro/etc. performance exhaust system had been added -- something which hundreds, if not thousands, of Z-owners did in the 1970's.

I have a different opinion about the early-version cars with the cabin air extractor vents located on the hatch panel.  I think that design may have been inherently weak, even when the cars were fairly new, because the open water-drainage tubes provided a secondary airflow exit (or entrance, depending on the circumstances) at an aerodynamically-undesirable location that also happened to be fully exposed to exhaust fumes caught in the 'bubble' that sets up behind the rear valence/trim panels when the car is in motion.  Once the 'one-way' flaps and/or the hatch interior trim panel started to get tired, or the hatch interior trim panel was improperly installed, you had all the necessary ingredients for exhaust fumes being sucked back into the cabin -- esp. when the side windows were opened a bit and changed the pressure differential between the cabin interior and the location of the drain tube exits.  I don't think this arrangement could be called a 'defect', because Nissan development engineers surely would have noticed the problem during the car's development.  However, problems must have begun to be reported after the cars had been in owners' hands for a year or so.  The change to the air extraction design was a costly move for Nissan and I don't think they would have taken it without figuring that they had no other choice.

I wonder if anyone with 1970's driving experience with a Series 1 car would care to comment on whether they have any recollections of exhaust fumes coming up into the cabin?

[djwarner]

There are two common aspects to fume intrusion, both are related to age and maintenance. First is the length of the exhaust pipe. It should extend beyond the rear valance by several inches so the exhaust gases mix with air that has separated from the body.

Second is deterioration of the grommets surrounding the vent hoses entering the passenger compartment behind the vinyl finishing pieces at the rear bulkhead.

Some have  cited air turbulence caused when the rear tires rotate upward into the rear of the wheel wells. They suggest adding mud flaps there to break up the turbulent rearward of the wheel well. This of course also existed when the cars were new and didn’t cause fume intrusion.

While you are at it, check the rear hatch gaskets. Both the one around the perimeter and the air exhaust vents in a series I car. These exhaust vents have rain drains with gaskets that can be compromised over time.

Properly maintained, your Z should not suffer from fumes. Don’t settle for less than fume free.