Exhaust fumes in cabin

[sdinath]

Hi Guys,

I've been getting a strong smell of gas/exhaust fumes in my cabin.

It seems that there is airflow coming into the cabin from between the quarter panels and then into the cabin by the panels next to the back seat.

I'm not sure how air can flow from the engine compartment into the quarter panels but at the moment I don't have

the engine firewall covers so I'm not sure if this is the problem.

Does anyone have an idea what could be the issue?

Thank you
Shaheed

[sdinath]

If this is a Beetle then it's most likely caused by the cabin heating system.

Old heat exchangers are invariably worn where they mate with the silencer and the nasty doughnut seals don't work because the pipes don't fit tight. This is the reason most ACVW heating systems are disconnected.

Firstly, you need a tightly fitting, leak free exhaust system, either with J-pipes or heat exchangers. If you don't plan to use the (dangerous) cabin heaters, then I suggest you pull off the heater pipes where they enter the car behind (FIF) the back seats and plug the entry holes into the car (appropriately sized aerosol caps work well), before refitting the heater pipes. That will keep fumes, dust, etc from entering the cabin from under the rear of the car.

[sdinath]

Dear fig

Thank you for reply.

Yes its a Beetle 1600s. The car's heating system has been disconnected and I've already sealed of the two vents that are under the back seat
so the fumes are definitely not coming in from there.

I''ve attached a picture of where the airflow is entering the cabin on both sides (circled in red). This picture was taken while
the car was being resprayed. At the moment the full interior has been refitted.

I'll appreciate your comments of what the issue could be.

Kind regards
Shaheed

[sdinath]

if it is coming in through the spot you highlighted, then I suspect you have a pretty big exhaust leak. That area is linked to the very top corners of the engine bay and is where the loom runs through on some models - this area should only be filled with clean cool air.
Either that or you have a aftermarket exhaust which ends up in a spot where the air gets pulled back into the engine bay?

[sdinath]

What Tony Z said /\

[Dawie]

Beetles came with type of cushions stuffed between the cavities which connect interior and engine compartment.

These cushions would absorb dampness and cause rust near lower corner-edges of rear window.
Often the sealing cushions woud be chucked out during a rust removal/respray episode, leaving the cavity open.

[sdinath]

if it is coming in through the spot you highlighted, then I suspect you have a pretty big exhaust leak. That area is linked to the very top corners of the engine bay and is where the loom runs through on some models - this area should only be filled with clean cool air.
Either that or you have a aftermarket exhaust which ends up in a spot where the air gets pulled back into the engine bay?

Hi Tony

I'll have the exhaust checked out. Its a Standard exhaust system. I attached a picture of the engine bay.

Do you think if I seal the top corners in the engine bay with a foam sealant this will affect the cooling system seriously?

[sdinath]

Beetles came with type of cushions stuffed between the cavities which connect interior and engine compartment.

These cushions would absorb dampness and cause rust near lower corner-edges of rear window.
Often the sealing cushions woud be chucked out during a rust removal/respray episode, leaving the cavity open.

Hi Dawie

Do you think if I seal the top corners in the engine bay with a foam sealant this will affect the cooling system seriously?

Thanks

[sdinath]

Gentlemen thank you for all your comments.

I think I've found the problem!

The (oily) air is flowing through the holes in the tinware in front of the engine and then through the cavities in the engine bay into the car interior (see attached pics).

I'll have to find something suitable to cover the tinware holes and I was thinking instead of putting a foam sealant (looks like a very bad idea after I researched the 'death foam') in the engine bay corner holes I could just put a removable piece of sponge to block off any fumes for now.

Thanks for all your help figuring it out!

Kind regards

[Edmond]

Cut some discs from thin sheetmetal and rivet or screw them over the holes in the tin ware. You need to cover or block those holes otherwise your engine will overheat as it will draw hot air from under the engine like it's doing now instead of drawing air through the engine lid vents

[John Alves]

Cut some discs from thin sheetmetal and rivet or screw them over the holes in the tin ware. You need to cover or block those holes otherwise your engine will overheat as it will draw hot air from under the engine like it's doing now instead of drawing air through the engine lid vents

if you place the tin under the holes and rivet from top, it will look neater, I've used aluminium flashing before, easy to cut and shape into place

[Dawie]

The purpose of the bendable metal plate is to keep the sealing cushion from falling out.


If you do put something back in there maybe put it inside a plastic bag so that it does'nt absorb dampness. The little "through-flow ventilation holes" next to the side windows were introduced in 1971. This is were rain enters, causing the wet cushion/rust issues.

[sdinath]

Thanks Dawie will do.

Kind regards
Shaheed