Exhaust fumes

[therat04]

The stag has developed a passion for sucking in exhaust fumes, this is a fairly recent problem that only happens with soft top up and window or windows open.
With the windows shut the air is pure leatherette and b.o. lovely...i have checked the exhaust manifold connections they seem ok, holes in the bulkhead, yes a couple where the grommet needs a replacement but nothing very big as the spaces are taken up with wiring and oil gauge pipes etc. the boot seal is ok. cant find any holes from the boot to the cab.
My logic says that the exhaust is being sucked into the car from the tail pipes a bit like the windflow over an aircraft which creates a vortex, not sure why it should start being a problem now but to be fair the car spends most of the year with the top down, any advice chaps before the whole car ends up in a pile of bits on the drive!!! this is giving me a headache both in and out of the car...Steve

[AlanD]

gear stick surround? manifolds?

could be joint, does it do it when hot or cold or both?

[therat04]

gear stick surround? manifolds?

could be joint, does it do it when hot or cold or both?

Hello Alan in this weather the windows are closed, i only notice the problem when i open the windows after the car has warmed up, i have thought that the heater was sucking exhaust fumes from the engine bay, but it is still there when the heater is off...Steve

[404ROD]

When you say the heater is off have you just turned off the blower? If this is the case air is still drawn into the car, via the grille in front of the windscreen, by the car's forward motion. You have to use the lever controls in front of the gear stick or the controls on the central air louvres and the fresh air vents each end of the fascia to completely stop air being drawn into the car.


Rod

[38rover]

I have had this problem in the past (not STAG) try the boot seal or any openings where gas could enter

[jleyton]

Hi Steve,

If all is running ok, there shouldn't be any escape of exhaust fumes other than at the tailpipes.

As you have surmised, these could be getting sucked back into the car by the vortex action, however if you get someone to block the tailpipes whilst the engine is running it should show you if/where you've got a leak on the exhaust line.

If no leaks are apparent then, at least you've ruled this out of the equation and you can concentrate on the back end.

Good luck.

Julian

[therat04]

When you say the heater is off have you just turned off the blower? If this is the case air is still drawn into the car, via the grille in front of the windscreen, by the car's forward motion. You have to use the lever controls in front of the gear stick or the controls on the central air louvres and the fresh air vents each end of the fascia to completely stop air being drawn into the car.


Rod

Hello Rod i have tried with all vents and levers set to off, still smells...Steve

[therat04]

I have had this problem in the past (not STAG) try the boot seal or any openings where gas could enter

Thanks the search will go on...Steve

[therat04]

Hi Steve,

If all is running ok, there shouldn't be any escape of exhaust fumes other than at the tailpipes.

As you have surmised, these could be getting sucked back into the car by the vortex action, however if you get someone to block the tailpipes whilst the engine is running it should show you if/where you've got a leak on the exhaust line.

If no leaks are apparent then, at least you've ruled this out of the equation and you can concentrate on the back end.

Good luck.

Julian

Hello Julian i hope you are keeping well, thats a good idea i will employ the trout for half an hour or so tomorrow should only cost me a manicure or similar... thanks ...Steve

[jleyton]

Hi Steve,

Hope it works for you. I'm great thanks and it's good to hear from you. Is it my imagination or have you not been on here quite so much recently ? I know, your car's running just fine and you don't need any advice

Btw I do think your car looks great with its matching coloured hood

Cheers

Julian

[AlanD]

Hi Steve,

just logged back on,as Julian has said try blocking the exhaust to test it, and then as others have said block the air intake, take off the grill, 3 screws, and put a towel in it, taker her for a run and try that, not with a blocked exhaust though, when she is cold things contract and tighten up, but as she gets warm things that were tight will become loose, it's trail and error i'm affraid, best of luck and i hope you get it sorted soon, i would guess it's a joint, but it is just a guess

Alan

[therat04]

Hi Steve,

Hope it works for you. I'm great thanks and it's good to hear from you. Is it my imagination or have you not been on here quite so much recently ? I know, your car's running just fine and you don't need any advice

Btw I do think your car looks great with its matching coloured hood

Cheers

Julian

Thanks for the comments on the car Julian i do try... your right the car is running the best it has ever run, the fitting of the weber carbs have made all the difference for me so although i have been silent on the forum i look at it every day and read all the threads, i see you have a nice new action shot of your lovely green stag for your avatar...Steve

[therat04]

Hi Steve,

just logged back on,as Julian has said try blocking the exhaust to test it, and then as others have said block the air intake, take off the grill, 3 screws, and put a towel in it, taker her for a run and try that, not with a blocked exhaust though, when she is cold things contract and tighten up, but as she gets warm things that were tight will become loose, it's trail and error i'm affraid, best of luck and i hope you get it sorted soon, i would guess it's a joint, but it is just a guess

Alan

Thanks for the info Alan i will try all these things out, i am just a bit puzzled why i cannot smell fumes with the window shut!...Steve

[AlanD]

Hi Steve,

that is what makes me think it is a joint, if you could smell it with the windows shut i would say air vents, but if it stops with the windows shut then it sounds like it is pulling it in with the frsh air comming into the car, hense why i thought it was from the engine bay, the air the fan pulls in will exit mostly under the car.

hope you sort it, we have sunshine tomorrow!! so they say, a good day to have a look, if you cant see the leak on the pipes listen for a hissing sound

[GDPR]

This is a common problem and is usually down to the boot seal, tail light gasket split or a grommet for towbar wiring missing. With the window open, the air rushing past creates a venturi effect and sucks air/exhaust gas from the boot space through the inner wings and out into the cabin through the ragtop horseshoes. Some of you would have had a fuel tank leak in the past and noticed the smell was worse when the windows were open - same reason.

The Weber may be adding to the problem by running a little lean making the exhaust gas a bit smellier - give the back end seals a good check and give the carb 1/2 turn richer.

Russ