87 yj exhaust fumes.

[segator]

What would cause exhaust fumes inside while driving around? My exhaust pipe is normal like any other jeep, or would it come through the back flap. Have grandchildren so really need to get a fix on this one so they can enjoy the ride.

 

[Sine Deviance]

What would cause exhaust fumes inside while driving around? My exhaust pipe is normal like any other jeep, or would it come through the back flap. Have grandchildren so really need to get a fix on this one so they can enjoy the ride.

A few possibilities here.

1. You have an exhaust leak somewhere under the passenger compartment, probably closer to the front of the Jeep. This is the most common problem, OEM-style exhaust systems usually only last for five or so years before they start to leak. If you had a leak in the exhaust manifold, the exhaust leaking from it would blow in through the vents. If it is directly under the passenger cabin, i.e. after the catalytic converter, it could leak up through holes in the floorpan that are there for the drain plugs and other misc things. Heat rises so it will always go up. Generally if you have an exhaust leak you will hear the difference; the exhaust will be slightly louder for a small leak and very loud for a large leak, especially if it's in the exhaust manifold (think NASCAR loud; you'd be able to hear it coming a mile away.) However, if the leak isn't very serious you may not notice an audible difference at all, but you still would be able to smell it.

2. You have a soft top and the soft rear window is of the type that doesn't seal on a rail on the rear tailgate. These are called easy tailgate windows. Basically this allows you to open the rear tailgate without unzipping the rear window. However, there is a gap of an inch or two between the top of the tailgate and the bottom of the rear window, which would be plenty to let exhaust from the tailpipe in. Mine is a Bestop Sailcloth Replace-A-Top and it is made like this. I have a '95 YJ so it would probably be the same for yours if you're using a Bestop. As far as I know, stock soft tops were not made like this.

3. If you checked the exhaust and you are sure beyond a shadow of a doubt that there is no leak, and if you do not have an easy tailgate rear window, the only other possibility is that the rear windows are leaking somewhere and allowing exhaust to blow back in. If you have a hardtop check all of your rubber seals back there; might be time to replace them. If you have a soft top, a little bit of blowback is normal just because of the design; they are designed to breathe a little in the zipper areas. In any case, check all of your zippers and window vinyls for any rips or tears.

 

[segator]

Thanks for the suggestion.