My car suffers from terrible fumes that come in to the cabin, that makes long drives unpleasant. This is off course with the windows up and the roof on. These get to the back on my throat but no smoke is particularly visible. I checked the seal of the glass around the door aperture on the passenger side (exhaust side) and that seems okay (for a nearly 30 year old car anyway !) the glass does come up to the edge of the seal. Could this be impending engine recondition time (the car passes the UK MOT emissions test okay) or could I do something to seal the cabin up better. I wonder what a cylinder head recondition would do in this area. I was thinking of blanking off the two small vents in the sail pillars. But whether this just amounts to futile tinkering I don't know.
Fumes in to the cabin
- Thread starter Phil_UK
- Start date
Pete Whitstone
True Classic
Exhaust fumes? Gasoline vapor fumes? Rubber burning smell fumes? What are we talking about here?
rocco79/138
True Classic
Usually we need way more to go on... What year car? FI or carb?
Just going from your post I will assume exhaust since you mentioned no smoke. Since all of the exhaust stuff is behind the engine you probably aren't getting exhaust in the cabin. Even with a poor seal on my header gasket I did not get fumes in my cabin.
I would check the crankcase vent line it comes off the front of the engine between the engine and the firewall next the the distributor. Make sure it is properly attached to the bottom of the air filter or the tube from the air meter to the intake plenum. If this is not properly attached you would be pumping smelly exhaust like fumes all in the bay. Also make sure there is no opening between cabin and engine bay. There are a few things that pass through the firewall. Wiring and the heater pipes are a few. Make sure they pass through some type of grommet or have packing around them to seal the cabin from the engine bay.
X1/9s all have a smell in and around the engine bay but this really should not ever get in the cabin if all the bits used to seal things are in place.
If the gasket around the fuel access is missing and your rear shelf speaker are gone that might be a source as well.
Just guessing all the way but I would look for evidence of shoddy work as a possible source. Not that you did poor work but some things that might seem more trouble than worth to restore after a repair may be the root of your problem.
Good Luck! Let us know what you find...
Regards
Just going from your post I will assume exhaust since you mentioned no smoke. Since all of the exhaust stuff is behind the engine you probably aren't getting exhaust in the cabin. Even with a poor seal on my header gasket I did not get fumes in my cabin.
I would check the crankcase vent line it comes off the front of the engine between the engine and the firewall next the the distributor. Make sure it is properly attached to the bottom of the air filter or the tube from the air meter to the intake plenum. If this is not properly attached you would be pumping smelly exhaust like fumes all in the bay. Also make sure there is no opening between cabin and engine bay. There are a few things that pass through the firewall. Wiring and the heater pipes are a few. Make sure they pass through some type of grommet or have packing around them to seal the cabin from the engine bay.
X1/9s all have a smell in and around the engine bay but this really should not ever get in the cabin if all the bits used to seal things are in place.
If the gasket around the fuel access is missing and your rear shelf speaker are gone that might be a source as well.
Just guessing all the way but I would look for evidence of shoddy work as a possible source. Not that you did poor work but some things that might seem more trouble than worth to restore after a repair may be the root of your problem.
Good Luck! Let us know what you find...
Regards
rocco79/138
True Classic
That's what I thought. Still can't conceive of a way exhaust can enter the cabin but if you have engine wear and some blow by there will be exhaust in the crankcase and out the vent which is next to the cabin...
dragonsgate
True Classic
First obvious thing is find the source of the leak. One way for the fumes to get in the cab is the center hump where the shift rod, throttle cable and e-brake runs. Years ago when I was first messing with electric drive I toasted a motor. The rubber seal where the shift rod comes out was gone and the smoke sucked up the tunnel out around the console into the cab.
ive recently purchased an X and noticed the smell of exhaust fumes with the roof off and windows down is nauseous. Having looked further the exhaust box has holes either side and is blowing. Im looking to replace the old exhaust with a new SS system but would this cure the fumes in the cabin?
I haven't yet been able to test the crank case pipe theory as until now I hadn't been able to source any 22mm ID pipe from my local motor factors 
Although I did remove the pipe and inspect it, it has small cracks but no actual holes through that I could see. I also swapped the one spring clip for two jubilee clips (added one to the air filter box end). The car seems a bit nicer on a drive now, but I am due to fit the new pipe to test.
Although I did remove the pipe and inspect it, it has small cracks but no actual holes through that I could see. I also swapped the one spring clip for two jubilee clips (added one to the air filter box end). The car seems a bit nicer on a drive now, but I am due to fit the new pipe to test.
artz1731
True Classic
Pete, I have noticed that just a slight change to either the tailpipe or rear bumper configuration can lead to fumes being sucked into the cabin. I believe a tailpipe with a slight bend away from the car would help this. I only started getting fumes in the car after I removed the stock rear bumper. My theory is that the air coming from under the car when moving curls up and into the cabin...of course it's just a theory.
It could be that I am running a little to rich also
.
geekdaddy
X1/9 Learner's Permit...
Do you have the same problem with the top off?
Is it worse or the same when moving vs idling at stop? When moving is the fresh air scuttle in the cowl open or closed? If a non A/C car are the dash side vents open? Having the fresh air vents and scuttle open while driving would push a lot of fresh air into the cabin and seems odd that fumes could make their way "forward" into the cabin.
On my U.S. vehicle, some "plumbing" for cooling and harnesses travel thru the spare tire well and all have rubber gaskets around them. I assume some engine vapors and smells could push into those areas into the cabin if there are any unsealed openings there.
Is it worse or the same when moving vs idling at stop? When moving is the fresh air scuttle in the cowl open or closed? If a non A/C car are the dash side vents open? Having the fresh air vents and scuttle open while driving would push a lot of fresh air into the cabin and seems odd that fumes could make their way "forward" into the cabin.
On my U.S. vehicle, some "plumbing" for cooling and harnesses travel thru the spare tire well and all have rubber gaskets around them. I assume some engine vapors and smells could push into those areas into the cabin if there are any unsealed openings there.
lookforjoe
True Classic
When I redid my exhaust the second time (with Magnaflow muffler) I angled the exhaust tips slightly to the sides instead of straight back. That was a bad idea. Some exhaust fumes would enter the cabin. Just idling, if I opened the door I could smell the exhaust. I redid them pointing straight back & that was resolved. Length of exhaust tip seems also relevant as too short a tip (relative to rear sheet metal, original late rear bumper removed) also seems to induce fumes in the cab.
So, from my experience, length & positioning of tailpipes makes a significant difference in terms whether any fumes as sucked in at rest or in motion.
Crankcase vapors would also be nasty. What about EVAP also? Any breaks in the lines for the that system will also fuel vapors to escape.
So, from my experience, length & positioning of tailpipes makes a significant difference in terms whether any fumes as sucked in at rest or in motion.
Crankcase vapors would also be nasty. What about EVAP also? Any breaks in the lines for the that system will also fuel vapors to escape.
Sorry for the (very) delayed response, I don't get much time to look at the car these days
Thank for for the helpful responses.
After its first drive in many months, I can confirm its still the same. It really makes driving this car unpleasant, I can still "taste" the fumes many hours later! The fumes build up even with roof on / windows up / fresh air vents open, this is most noticeable when driving at highway speed. I checked and the carpet underlay stuff in the spare tyre compartment is ripped and missing and reveals some small holes through to the centre tunnel. I will need to find something to put over these. I haven't had a close look under the car, but I did check that the gaiter that joins the gear linkage to the car body is present and doesn't seem damaged. I had a look at the Haynes manual page 163 (for the underneath photo) and saw a gap just forward of the previously mentioned gaiter where it looks like a cover for an access panel is missing ( I haven't been able to look at this on my car though). Its interesting because I did get the handbrake cables replaced and this could be an access point for their adjustment. Quite where I'd find a replacement is another matter!
Thank for for the helpful responses.
After its first drive in many months, I can confirm its still the same. It really makes driving this car unpleasant, I can still "taste" the fumes many hours later! The fumes build up even with roof on / windows up / fresh air vents open, this is most noticeable when driving at highway speed. I checked and the carpet underlay stuff in the spare tyre compartment is ripped and missing and reveals some small holes through to the centre tunnel. I will need to find something to put over these. I haven't had a close look under the car, but I did check that the gaiter that joins the gear linkage to the car body is present and doesn't seem damaged. I had a look at the Haynes manual page 163 (for the underneath photo) and saw a gap just forward of the previously mentioned gaiter where it looks like a cover for an access panel is missing ( I haven't been able to look at this on my car though). Its interesting because I did get the handbrake cables replaced and this could be an access point for their adjustment. Quite where I'd find a replacement is another matter!
kmead
Old enough to know better
Try this. Have a look into the spare tire well.
On the right side there is a ‘wood’ based panel to the outside of the space (right side of the car when viewed from the back). If this is in bad shape, has gaps or other issues, it can serve as a conduit directly from the location of the tailpipe around the engine compartment into the passenger compartment.
If you have openings which are poorly sealed in the trunk, the fumes can go up into the trunk, up over the wheel well and then to the opening covered by the poorly fitting chip board panel. By the way this is a great way to fish a wire from the passenger compartment all the way back into the trunk that keeps the wire away from weather and heat.
I would look into making a new panel out of ABS or similar plastic, as they often get water damaged. I would then use aluminum tape used for sealing ductwork on a furnace (not duct tape, thats garbage) to seal the edges and any other gaps you feel like. Just make sure the surface is clean without dirt and grease/oil and this stuff will stay for years. You can use any tape that meets UL1581A. Home Depot etc will carry this, one roll will cover a lot of X1/9 gaps, holes and cracks. Your car will be quieter too.
On the right side there is a ‘wood’ based panel to the outside of the space (right side of the car when viewed from the back). If this is in bad shape, has gaps or other issues, it can serve as a conduit directly from the location of the tailpipe around the engine compartment into the passenger compartment.
If you have openings which are poorly sealed in the trunk, the fumes can go up into the trunk, up over the wheel well and then to the opening covered by the poorly fitting chip board panel. By the way this is a great way to fish a wire from the passenger compartment all the way back into the trunk that keeps the wire away from weather and heat.
I would look into making a new panel out of ABS or similar plastic, as they often get water damaged. I would then use aluminum tape used for sealing ductwork on a furnace (not duct tape, thats garbage) to seal the edges and any other gaps you feel like. Just make sure the surface is clean without dirt and grease/oil and this stuff will stay for years. You can use any tape that meets UL1581A. Home Depot etc will carry this, one roll will cover a lot of X1/9 gaps, holes and cracks. Your car will be quieter too.
myronx19
True Classic
exactly - this hose needs to run back to the carb so it can be part of the combustion process. He should check if it's connected.
My car kinda stinks as well, but I do have a catalytic converter and a Faza 35/75 on an injected car. But, it doesn't stink enough to bother me. Windows up, no issues.
I seem to have mostly solved this by blocking up the rear cabin vents.
The fumes must have been coming in through above the holes in the rear compartment above the exhaust muffler and going past the edges of the false floor and up through the inner rear wheel arches to the rear cabin vents.
Re, the panel Karl is talking about, a few years back I replaced the wooden panel in the spare tire well with a piece of MDF board that fits exactly to the gap, which was varnished and I added a rubber seal around the edges of the sheet metal. This still seals well.
The fumes must have been coming in through above the holes in the rear compartment above the exhaust muffler and going past the edges of the false floor and up through the inner rear wheel arches to the rear cabin vents.
Re, the panel Karl is talking about, a few years back I replaced the wooden panel in the spare tire well with a piece of MDF board that fits exactly to the gap, which was varnished and I added a rubber seal around the edges of the sheet metal. This still seals well.
tvmaster
True Classic
Old thread revival time:
Phil_UK mentioned blocking the ‘rear cabin vents’? Do you understand what he meant? After a week of driving our recent ‘74 purchase, today I really started to notice exhaust fumes in the cabin. Roof off, windows up, heater on. On a longer, freeway drive with roof on and windows up, heater off, didn’t notice the fumes as much. So all that being the case, if we’re driving in city traffic, it got pretty stinky with exhaust fumes. I’m not sure where they’re coming from, but it has me concerned.
Previous owner outfitted car with quasi-phony, dual rear exhaust pipes (meaning there are two pipes on each side, but only one on each side is actually active).
So what are these side vents he speaks of?
I have access to a lift next week - any thoughts on where to look for leaks, or on a stinky ‘74, are exhaust fumes part of the experience? Kinda thinking Co2 inhalation not a good thing while driving...
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