How to stop fumes in cabin?

[RobFrost]

On Mike Bainbridge's advice I ran the 1970T for 5-10 minutes this p.m. and as he predicted it might, the smoke eventually cleared - which was a great result! However the cabin was completely full of smoke despite the doors and windows being closed. I intend to drive this car to its MOT next week without committing suicide en route. Is it a fair assumption that the fumes are being pumped in by the heating system, given that the exhaust is badly corroded and visibly holed in several places? What's a good fix to stop the ingress of fumes?

Am I right in thinking the aluminium hoses in the engine bay are integral to this problem?

[RobFrost]

Also I made another video, this time revving a bit higher.

https://photos.app.goo.gl/PkfBYZVfVQ2KsuE38

[impmad2000]

The heater blows air directly over the exhaust manifolds and down the sill ducts to the cabin. Any holes in the manifold pipes will let fumes into the air flow. You have two basic choices. 1) disconnect the heater pipes from the sill ducts, disabling the heater. Or 2) replace the heat exchangers. If it is exhaust fumes them beware of Carbon monoxide poisoning yourself. A headache and nausea are the clues especially if it clears after getting into fresh air.
My car has some oil leak onto the manifold pipes ( drips off the cam covers). This smokes for a bit until burned off and then becomes acceptable. This smoke can make its way to the cabin too. Targa top off and 1/4 vents wide open help.
Replacing heat exchangers can be quite tricky as head studs may (will) sheer.
Good luck
Tim

[sladey]

Wot Tim said.

I understand it’s quite unusual (but not impossible) for exhaust fumes to be coming through - what is more common is that oil drips inside the heat exchanges and it is the oil fumes/smoke that are coming through

But best to err on the side of caution

[Nige]

Depending on your MOT guy even if the hoses are removed the damaged/rusty heat exchangers may still be a fail. Hopefully he isn't aware of them and passes it.

You need to get under the car and follow where the heat exchangers enter the sills/chassis. You will find a length or flexi hose about 6" long-ish, remove both sides.

As Tim mentioned, removing the heat exchangers can be a world of pain with snapped studs. You are probably best cutting as much of the the old exchangers off leaving just a stub of of pipe and the flanges, this will allow access to the studs, then carefully cut the nuts of the studs with a dremel or similar.

[RobFrost]

Depending on your MOT guy even if the hoses are removed the damaged/rusty heat exchangers may still be a fail. Hopefully he isn't aware of them and passes it.

You need to get under the car and follow where the heat exchangers enter the sills/chassis. You will find a length or flexi hose about 6" long-ish, remove both sides.

As Tim mentioned, removing the heat exchangers can be a world of pain with snapped studs. You are probably best cutting as much of the the old exchangers off leaving just a stub of of pipe and the flanges, this will allow access to the studs, then carefully cut the nuts of the studs with a dremel or similar.

thanks. I've been advised it may just be the heated oil and no exhaust fumes so maybe once the oil's burned off it'll stop. Might take the hoses off for safety, for the time being.