Exhaust smell in cabin

tara · Post by **tara** » Fri Jun 09, 2017 7:01 pm

Hi guys
New exhaust has just. Been built for my 327, it is 2 1/4 pipe all the way with thrush turbo muffler, the tip is right in front of the passenger rear wheel
I was expecting no more smell in ca in when driving with windows opened
Ut i can still smell some
How come.
Thks
Tara

FSJ Guy · Post by **FSJ Guy** » Fri Jun 09, 2017 8:22 pm

Probably because your exhaust is forward of the rear wheels. <shrug>

Dumping it out at the factory location might help.

tara · Post by **tara** » Fri Jun 09, 2017 8:28 pm

It seems that it is the original location in front of the rear wheel for my year

Tatsadasayago · Post by **Tatsadasayago** » Sat Jun 10, 2017 2:49 am

Often whether the exhaust pipe exits before or after the rear wheel the vacuum created by the back of the jeep causes exhaust gasses to enter the cabin via weak window/tailgate seals and is compounded if there are rust holes in the lower quarter panels and tailgate/glass.
You can minimize this by opening the kick panel air vents and front door windows until there is positive air pressure in the cab.
There was an add-on fix for this back in the day: Spoilers. The wing at the top of the rear body or a pair of side spoilers would blow air across the rear window to keep dust off. It also worked to keep the exhaust out of the cabin by reducing the airflow vacuum at the rear tailgate/window.

I was having an exhaust smell in the cabin on my Chief (With all new seals) and extending the tip of the exhaust behind the rear tire about 4" away (Away from the body) from the tire solved it.

tgreese · Post by **tgreese** » Sat Jun 10, 2017 5:49 am

tara wrote:It seems that it is the original location in front of the rear wheel for my year

Nope. Look at the parts book. All Wagoneers go over the rear axle and out the back. Trucks exit in front of the rear wheel, but not Wagoneers.

tara · Post by **tara** » Sat Jun 10, 2017 11:21 am

tgreese wrote:
tara wrote:It seems that it is the original location in front of the rear wheel for my year
Nope. Look at the parts book. All Wagoneers go over the rear axle and out the back. Trucks exit in front of the rear wheel, but not Wagoneers.

ok, i thought it was for my model too. but searching on the wensites for similar issue, i found that many guys which got cars with large tailgate window have exhaust fumes sucked in the cabin, even with rear tips after the wheels

tgreese · Post by **tgreese** » Sat Jun 10, 2017 12:41 pm

When you say "windows opened" I read that as side windows down, not tailgate window down. AFAIK no station wagon exists that can be driven with the tailgate window open and not have fumes in the car. I expect if you look at the owners manual, it will tell you only to drive with the tailgate window completely shut.

tara · Post by **tara** » Sat Jun 10, 2017 5:19 pm

tgreese wrote:When you say "windows opened" I read that as side windows down, not tailgate window down. AFAIK no station wagon exists that can be driven with the tailgate window open and not have fumes in the car. I expect if you look at the owners manual, it will tell you only to drive with the tailgate window completely shut.

Ok
If i drive the car with rear and tailgate windows closed
I have less fumes inside but i can still smell a little. it scares me cos it is very bad for the health, do you advise me to make install a new exhaust pipe with the tip at the rear of the rear axle ?

like this
http://www.2040-cars.com/_content/cars/ ... 24/007.jpg
little oriented downward ?
thanks

tara · Post by **tara** » Sun Jun 11, 2017 10:53 pm

RamJetFSJ · Post by **RamJetFSJ** » Tue Jun 13, 2017 7:33 am

Exhaust should always exit behind the passenger compartment. On a Cherokee, you could exit it there, but with a window that opens on the rear doors, its really not OK on the Wagoneers. But, if your still getting fumes with all the windows closed, I would take a close look at all your weather stripping and check for holes in the floor, making sure its not entering the cabin some where. But yeah, I would suggest having it exit anywhere behind the rear wheels, and not drive with the tailgate window down.

letank · Post by **letank** » Tue Jun 13, 2017 4:36 pm

tara wrote: If i drive the car with rear and tailgate windows closed
I have less fumes inside but i can still smell a little. it scares me cos it is very bad for the health, do you advise me to make install a new exhaust pipe with the tip at the rear of the rear axle ?

like this
http://www.2040-cars.com/_content/cars/ ... 24/007.jpg
little oriented downward ?
thanks

Yes, this is the stock look, but even with that configuration you may have some fumes... if the gasket around the tailgate is dry and shrunk exhaust may still percolate inside

will e · Post by **will e** » Tue Jun 13, 2017 6:56 pm

Are you sure you are smelling exhaust and not fumes from the engine compartment? Check the firewall and see if there are any large openings.

tara · Post by **tara** » Wed Jun 14, 2017 2:36 pm

will e wrote:Are you sure you are smelling exhaust and not fumes from the engine compartment? Check the firewall and see if there are any large openings.

yes it is more than possible that i got too fumes from the engine. gona check that too
thanks to you all for your help

44bz · Post by **44bz** » Wed Jun 14, 2017 5:49 pm

I can't help with your problem but I have the same problem. Mostly due to holes in the firewall and exhaust pipe ending just behind the cab. I just drive with the window down, keep the fresh air flowing

Sent from my iPhone using Tapatalk

Tatsadasayago · Post by **Tatsadasayago** » Wed Jun 14, 2017 6:11 pm

I came up with a cool method of finding out where the exhaust was entering the cabin on my first Cherokee:
I had a friend drive it down a very dusty dirt road with all the windows closed while I sat in the back of the cargo area. Immediately I could see dust coming from the bottom of the tailgate, around the rear window and from behind the passenger rear interior panel. New glass felts, outer wipe and gate seal fixed most of it and a rust hole repair in the lower rocker panel cured the rest.

tara · Post by **tara** » Thu Jun 15, 2017 9:14 am

will e wrote:Are you sure you are smelling exhaust and not fumes from the engine compartment? Check the firewall and see if there are any large openings.

there is one opening which is the transfer shift lever in the floor. i tried to install some large adhesive bands around it, but seems not perfect
There is a boot but no inner boot so i guess it is the perfect opening for fumes to enter the cabin if a. Vacuum is created when tailgate window is down

tgreese · Post by **tgreese** » Thu Jun 15, 2017 10:51 am

Yes, that could be a problem. It will be more of a problem if exhaust leaks before it gets to the tailpipe tip.

Can you make an inner boot? I would use rubber sheet and weatherstrip cement.

https://www.mcmaster.com/#standard-rubb ... s/=182yp60
https://www.amazon.com/3M-08008-Black-W ... rip+cement

Post by **Stuka** » Thu Jun 15, 2017 11:03 am

I have never seen any FSJ with exhaust that dumps in front of the rear wheels.

But all Waggies/Cheros should exist out the side behind the rear wheel. Exiting straight out the back can also suck in fumes.

Also, I ran my cherokee with a turn down in front of the rear axle, and it sucked fumes in. So changed it back behind the rear wheel, out the side, and it was fine.

tgreese · Post by **tgreese** » Thu Jun 15, 2017 11:10 am

tara wrote:... Vacuum is created when tailgate window is down

Do not drive with the tailgate window down.

tara · Post by **tara** » Thu Jun 15, 2017 11:24 am

tgreese wrote:
tara wrote:... Vacuum is created when tailgate window is down
Do not drive with the tailgate window down.

ok, i m now aware of it. when front windows are open, does it create vacuum too ?

Full Size Jeep Network