Unburned fuel smell ?

[gitchesum]

When I turn my heater on, I have an exhaust smell in the cab. What’s the path of air movement from out to in ?
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Looking for SP Kadron manifolds...please !!



57 SC
61 rag w/356B brakes
61 356B
Honda XLR 250, 69 Z50, Yamaha 100 Enduro...and others.
GMC SLT 4x4 Dmax
Kubota L3710, not enuf attachments.
And various VW's that come and go...

[airschooled]

I'm assuming this is regarding the '68 in your signature?

Air comes into the engine compartment through the body vents.
Air picks up all smells in engine bay.
Air goes through cooling fan, out the shroud, down grey/silver hoses into heat exchangers.
Air picks up all smells in heat exchangers.
Air moves out heat exchangers, into chassis tubes.
Air picks up all smells in chassis tubes.
Air comes out vents.

Clean heat starts with eliminating all the smells listed above. The heat exchanger itself is most often guilty; any oil leaked onto them will work inside and smell unpleasant. Engine compartment smells are next; usually missing tin, seals, or an exhaust leak sucked back into the engine compartment cause stinky intake air. Chassis smells happen when rodents make themselves at home in the ducting…

Got a picture of the engine compartment in question?

A big part of heater smells involves paying extra attention to the qualities of the smell. Is it sweet like oil? Pungent like fuel? Rancid like burning plastic? Chemically perfect exhaust has little to no smell, so if you're smelling oil, it's probably from drips on the heat exchangers, not the actual engine exhaust. If you're smelling gas, it might from a vapor line issue or exhaust leak/rich tune.

Give us more details and we'll give you more info!
Robbie
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[gitchesum]

Robbie,
First thank you very much for taking the time.
That's what I thought the path was too. Stock engine compartment, stock exhaust. I'm also suspecting the heat exchangers. Original to the bus, and quite old.
The smell I'm getting, is a very rich pungent smell, like you get from behind a car that's running too rich. Maybe like partially unburned fuel. It's not to the point of making your eyes water, but still uncomfortable.

I'll crawl under the bus again and try to see any defect in the HE's. :Likely inside where it can't be seen.

Thanks again for your response.
C
_________________
Looking for SP Kadron manifolds...please !!



57 SC
61 rag w/356B brakes
61 356B
Honda XLR 250, 69 Z50, Yamaha 100 Enduro...and others.
GMC SLT 4x4 Dmax
Kubota L3710, not enuf attachments.
And various VW's that come and go...