Stage 1 Exhaust Smell

[andersnd]

Greetings - I've purchased a 1981 3 door Stage 1 in Holland where I presently live, will be exporting back to the states in July.

I've had the truck for 3 months and am noticing exhaust fume smell in the cabin getting worse over time. I've confirmed that there are no leaks in the system itself - my rover mechanic here has inspected and confirms it is in good shape and tight. So what I'm left with is length of tailpipe which I've extended by 4 inches to get it out from under the rear left panel, but no real change to the smell of fumes. I've got some other issues to investigate such as valve stem seals to address white smoke at start-up, but I'm not certain that remedy will effect the intensity of smell. I've had other series rovers over the past 20 years or so and I'm used to the fact that exhaust smell is the nature of the beast, but have never had a v8 before. Not certain if I just need to expect twice as much smell because I have twice the number of cylinders.

Anyone else battled with these issues? Any advice as to troubleshooting/ remedy?

[disco2hse]

Hmm, there should be *no* exhaust smell in the cabin. If you can smell that, there will also be carbon monoxide that you cannot smell.

Sources of fumes I have found in the past:

1. Leaking exhaust manifold (leaking gasket and cracked manifold)
2. Leaking manifold an down-pipe junction. Once upon a time you would wrap a loop of asbestos braid around the junction - guaranteed not to leak and totally heat proof. Unfortunately, asbestos kills.
3. Leaking rear pipe junctions (they shake loose and whacked when off-roading).
4. If the pipe finishes under the rear mudguard, fumes can be sucked back into the cabin, especially if you have a station wagon, etc. I found this the case when I had a full rag top.
5. Otherwise, could be a leaking fume return pipe from the rocker cover to the air filter (mine were missing!).
6. The exhaust valves are not seating correctly and pumping fumes out the top of the engine (see point above).

[Firemanshort]

soft top or hard top?

[o2batsea]

You are always dragging a big wad of low pressure air behind the truck. Exhaust fumes build up in this area and if your body seals are not sealing, the fumes can sneak in. Go all around the tail gate and the side panels and if necessary stuff some insulation in there. Should solve it.

[amcordo]

Where does your exhaust pipe end? If it's a straight pipe - I found that the exhaust comes back into the vehicle from the rear door/windows. ...that may be a reason why OEM had the exhaust shooting out the side of the vehicle, rather than through a hole in the rear bumper.

[disco2hse]

You are always dragging a big wad of low pressure air behind the truck. Exhaust fumes build up in this area and if your body seals are not sealing, the fumes can sneak in. Go all around the tail gate and the side panels and if necessary stuff some insulation in there. Should solve it.

It's a Land Rover!

[andersnd]

Thanks for all your replies. The truck is a hard top. Rear seals on the back door are good. Driving with all windows/vents sealed up makes it much better, but in stop and go traffic it can still get bad in the cabin which makes you want to open windows and then the cycle begins. I know there is no cure all for the problem and that some level of tolerance to exhaust fumes is required but i am thinking that I may have a carb adjustment issue due to the truly pungent smell of the exhaust. I have the 123 electronic ignition system for the rover 3.5 v8 which I need to ensure is working properly - but my gut is that my mixture is rich right now resulting in an unusually strong smell to the exhaust. The tailpipe goes out the drivers side of rear panel and I have added about 3 inches of pipe to ensure exhaust is blowing out the side as opposed to the low pressure vacuum behind the truck. Will continue to work through this and will keep you all posted.

[disco2hse]

As I said, you should not be smelling *any* exhaust fumes. That is not the same thing as smelling oil, etc.

To be smelling exhaust fumes means you are also breathing in carbon monoxide. That can kill you, or it will make you dopey when driving, then you hit something and that kills you instead.

How did the guy confirm there are no leaks in the system? Did he do a pressure test?

Often leaks can be heard as a huffing sound.

If your air-fuel mix is out, in the cab you should not smell it although those outside will.

[1971Series88]

WELL...simple logic (and trusting your mechanic was 100% correct) says that if you have no system leaks in the manifold, connections, extensions or holes in any pipes...ie the entire exhaust system is 100% leak free.....then there is only one place the exhaust fumes come out - YOUR TAIL PIPE. If all that holds true then your issue like Bill pointed out is with your seals in tailgates/doors/windows etc etc....simple logic right?