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Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 9:01 am
by Wes
Whilst in traffic at the weekend on the way to a show i noticed a wisp pf grey black smoke coming from the front of the car. I was only a few mins from the show site so when i got there i got out leaving the engine running but couldn't see anything, not even with the bonnet open. Happened again on the way home so pulled off the main road safety and looked again, nothing but a faint trace for 'soot' on one of the grille slats. Every thing seemed to be running ok, no hint of overheating or fluid loss. Gave car a good once over when i got home, and again no sign s of anything. When cool i checked water and it was full. How could smoke be coming from in front of the radiator? weird.

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 9:02 am
by unclealec
Not Joseph Lucas smoke is it? Check the wiring.

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 9:54 am
by Wes
unclealec wrote: Mon Aug 24, 2026 9:02 am Not Joseph Lucas smoke is it? Check the wiring.
Good call. Never thought of that. But i can say there was deffo no acrid burnt electrical smell, i would have noticed that straight away.

Thanks

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 10:02 am
by svenedin
I wouldn't expect to see it at the radiator grille but the most likely candidate for smoke in the engine bay is the manifold to exhaust joint. Look for sooty marks there. Also inspect manifold to cylinder head gasket area and the manifold itself which can crack. Other much less likely causes, a seriously overheating wheel bearing, overheating brake drum, clutch contaminated with oil.

Stephen

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 10:57 am
by Bill_qaz
What type of breather do you have? If the bean can at front is it holed.
Have you got wiring near the mark, also is the sooty mark from the issue or coincidence, clean off and test run to check.
A good mystery for a Monday :wink:

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 11:11 am
by Wes
Bill_qaz wrote: Mon Aug 24, 2026 10:57 am What type of breather do you have? If the bean can at front is it holed.
Have you got wiring near the mark, also is the sooty mark from the issue or coincidence, clean off and test run to check.
A good mystery for a Monday :wink:
Now that's another good point. As its summer I've spun the Air filter canister round so the intake points forward, but this means the OE breather pipe doesn't reach/connect, ive instead temporally run a 1/2" pipe from the rocker cover down and through one of the holes in the engine bay floor to is exits to the ground. Maybe the wind was behind and blow the breather "exhaust" forward!

re the soot i did wonder if that came from someone else's exhaust in from to me.

Sounds like i need to revert the air filter to normal position, refit the OE breather pipe, wipe the grille slats and go for a drive.

Thanks all

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 11:14 am
by Wes
svenedin wrote: Mon Aug 24, 2026 10:02 am I wouldn't expect to see it at the radiator grille but the most likely candidate for smoke in the engine bay is the manifold to exhaust joint. Look for sooty marks there. Also inspect manifold to cylinder head gasket area and the manifold itself which can crack. Other much less likely causes, a seriously overheating wheel bearing, overheating brake drum, clutch contaminated with oil.

Stephen
More excellent ideas. I have discs so its not a drum issue. but bearing is good one. the gasket issues, wouldnt the fan blow that smoke backwards?

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 11:36 am
by Wes
svenedin wrote: Mon Aug 24, 2026 10:02 am I wouldn't expect to see it at the radiator grille but the most likely candidate for smoke in the engine bay is the manifold to exhaust joint. Look for sooty marks there. Also inspect manifold to cylinder head gasket area and the manifold itself which can crack. Other much less likely causes, a seriously overheating wheel bearing, overheating brake drum, clutch contaminated with oil.

Stephen
Again i dont think its sticky friction linings as i would have notied the smell, but i'll feel the wheels rims after a run

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 11:39 am
by michael4
Sooty dust made by the fan belt rubbing on something?

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 11:43 am
by svenedin
Wes wrote: Mon Aug 24, 2026 11:14 am
svenedin wrote: Mon Aug 24, 2026 10:02 am I wouldn't expect to see it at the radiator grille but the most likely candidate for smoke in the engine bay is the manifold to exhaust joint. Look for sooty marks there. Also inspect manifold to cylinder head gasket area and the manifold itself which can crack. Other much less likely causes, a seriously overheating wheel bearing, overheating brake drum, clutch contaminated with oil.

Stephen
More excellent ideas. I have discs so its not a drum issue. but bearing is good one. the gasket issues, wouldnt the fan blow that smoke backwards?
Yes the fan should blow the smoke backwards but it is not unknown for the wrong fan to bit fitted that blows the wrong way! (Such as from a Mini).

It sounds like it is steam with some oily fumes from your improvised breather.

Stephen

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 12:57 pm
by Wes
michael4 wrote: Mon Aug 24, 2026 11:39 am Sooty dust made by the fan belt rubbing on something?
That did cross my mind too but no sign of it

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 1:01 pm
by Wes
[/quote]

Yes the fan should blow the smoke backwards but it is not unknown for the wrong fan to bit fitted that blows the wrong way! (Such as from a Mini).

It sounds like it is steam with some oily fumes from your improvised breather.

Stephen
[/quote]


Yep, fault diagnosis to be:
1. Revert to OE Filter/Breather arrangement
2. Check loom
3..Check fan belt & direction of fan
4. Check for gasket blowing
5. Jack each front corner and feel/listen for bearings/dragging

Thanks

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 1:51 pm
by Bill_qaz
Wes wrote: Mon Aug 24, 2026 11:11 am
Bill_qaz wrote: Mon Aug 24, 2026 10:57 am What type of breather do you have? If the bean can at front is it holed.
Have you got wiring near the mark, also is the sooty mark from the issue or coincidence, clean off and test run to check.
A good mystery for a Monday :wink:
Now that's another good point. As its summer I've spun the Air filter canister round so the intake points forward, but this means the OE breather pipe doesn't reach/connect, ive instead temporally run a 1/2" pipe from the rocker cover down and through one of the holes in the engine bay floor to is exits to the ground. Maybe the wind was behind and blow the breather "exhaust" forward!

re the soot i did wonder if that came from someone else's exhaust in from to me.

Sounds like i need to revert the air filter to normal position, refit the OE breather pipe, wipe the grille slats and go for a drive.

Thanks all
You can get a longer breather pipe that reaches rocker cover vent to air cleaner in summer position, from memory I bought it from ESM.
Although my cover in pic is non std it was fitted to the original rocker cover. outlet
20250905_141012.jpg
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Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 3:56 pm
by geoberni
Not that it's related to your actual problem but....
Wes wrote: Mon Aug 24, 2026 11:11 am
Now that's another good point. As its summer I've spun the Air filter canister round so the intake points forward, but this means the OE breather pipe doesn't reach/connect, .......
.

All I've ever done in the past with cars of this vintage, ie ones I had in the 70s & 80s having such an inlet configuration, is have inlet over exhaust in the winter and turned away a bit in the summer.
Which in the case of the 1098 means up near the rocker cover, or by the exhaust manifold. A matter of a few inches not a full180 deg change.
When you consider the preceeding Minor air filter designs, I wonder if any change really makes a difference in our climate. 🤷🏻

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 4:44 pm
by unclealec
It could be the Morris Fairy having a quick ciggie in between mischievous tasks.

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 4:57 pm
by Bill_qaz
geoberni wrote: Mon Aug 24, 2026 3:56 pm Not that it's related to your actual problem but....
Wes wrote: Mon Aug 24, 2026 11:11 am
Now that's another good point. As its summer I've spun the Air filter canister round so the intake points forward, but this means the OE breather pipe doesn't reach/connect, .......
.

All I've ever done in the past with cars of this vintage, ie ones I had in the 70s & 80s having such an inlet configuration, is have inlet over exhaust in the winter and turned away a bit in the summer.
Which in the case of the 1098 means up near the rocker cover, or by the exhaust manifold. A matter of a few inches not a full180 deg change.
When you consider the preceeding Minor air filter designs, I wonder if any change really makes a difference in our climate. 🤷🏻
I thought its standard procedure for 1098 version, in winter its rearward close to exhaust manifold and in summer it forward under the carburettor float bowl.
Summer position
Summer position
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Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 5:51 pm
by geoberni
Bill_qaz wrote: Mon Aug 24, 2026 4:57 pm
I thought its standard procedure for 1098 version, in winter its rearward close to exhaust manifold and in summer it forward under the carburettor float bowl.20250213_151430.jpg
I think it depends on individual interpretation of information provided and how we pick things up from others over the years.
If you look in the workshop manual the only reference is this 'Note', hardly a definitive instruction on placement 🤷🏻.
.
Screenshot_20260824-171730_Drive.jpg
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When I had a Vauxhall Viva HC, it was just a case of towards the 'corner' in summer and down to exhaust in winter. :wink:
IMG_7182.jpg
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Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 6:09 pm
by Bill_qaz
geoberni wrote: Mon Aug 24, 2026 5:51 pm
Bill_qaz wrote: Mon Aug 24, 2026 4:57 pm
I thought its standard procedure for 1098 version, in winter its rearward close to exhaust manifold and in summer it forward under the carburettor float bowl.20250213_151430.jpg
I think it depends on individual interpretation of information provided and how we pick things up from others over the years.
If you look in the workshop manual the only reference is this 'Note', hardly a definitive instruction on placement 🤷🏻.
.
Screenshot_20260824-171730_Drive.jpg
When I had a Vauxhall Viva HC, it was just a case of towards the 'corner' in summer and down to exhaust in winter. :wink:
IMG_7182.jpg
So the Note is exactly what I referred to.
Because of the shape when rotated there is really only two positions.
Summer as per my picture or in winter its at the rear of the engine and close to the exhaust manifold. Never use mine in winter so just leave as pic.
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Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 6:39 pm
by geoberni
Bill_qaz wrote: Mon Aug 24, 2026 6:09 pm
So the Note is exactly what I referred to.
Because of the shape when rotated there is really only two positions.
Summer as per my picture or in winter its at the rear of the engine and close to the exhaust manifold. Never use mine in winter so just leave as pic.
Screenshot_20260824-180959_Samsung Browser.jpg
Or it just means rotate it upwards about 30 degrees or so such that it is up by the rocker cover, where the original 12G 285 breather pipe connection (about 7-8" long) still reaches, rather than getting a different one because you've done 180 rotation. There was only 1 hose listed.
There are not 'really only two positions' it's mounted on a circular plate...

Re: Tenuous/odd smoke question

Posted: Mon Aug 24, 2026 10:28 pm
by Bill_qaz
You mean like this but the the intake is still above the hot exhaust manifold so not drawing cooler air
Internet_20220104_203838_10.jpeg
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The breather pipe is a standard part from esm.
Breather Hose (Rocker Cover To Air Cleaner)
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