Diesel smell coming through air con vent

[Andrew Kikeros]

Hello - hoping for an answer to this - I have a 2016 70 Series workmate wagon and when first turn motor on and then air conditioner I get a diesel fuel smell coming through the vents for about 15-20 seconds. It's not emission smell it's definitely fuel. Got under and all over the motor and can't see any evidence of fuel leaks. Any thoughts? thanks Andrew

 

[Chris Boorer]

Just a thought check your vent is closed and not open for outside air

 

[StarCruiser]

I take your point about not finding a leak but to have a diesel smell, there has to be diesel present, either from a leak or from something containing it. Could it be coming from a slightly loose fuel filter or water drain? Or from diesel spilled historically? Do you have a pollen filter fitted that could have absorbed the smell and be giving you a waft each startup?

 

[Chris Boorer]

As far as im aware there is no possible way for diesel to enter the aircon vents, which is why I felt if the vents were open it could just be an extra bit of fuel on startup letting the fumes come in through the vent since its only for a few seconds after starting. Im no mechanic but im no slouch either, aircon and diesel just don't mix( pun intended lol) I would be interested in finding out what causes this as I have a 2017 79 series just incase it happens to me ?

 

[StarCruiser]

As far as im aware there is no possible way for diesel to enter the aircon vents, which is why I felt if the vents were open it could just be an extra bit of fuel on startup letting the fumes come in through the vent since its only for a few seconds after starting. Im no mechanic but im no slouch either, aircon and diesel just don't mix( pun intended lol) I would be interested in finding out what causes this as I have a 2017 79 series just incase it happens to me ?

My point was largely what you’ve just said Chris, (and not challenging your comment in any way) in that to smell diesel, there has to be diesel to smell. Ordinarily, in a properly functioning system, any fuel is admitted to the cylinders, burned and ejected as exhaust so the fuel has to be leaking from before the cylinders to smell of fuel, not exhaust. That is unless the fuel smell is present in something else, such as a rag or filter that may have come into contact with diesel, and be within reach of the air sucked into the vents, which, on my truck at least, stay on external air most of the time. In short, whatever position the air intake damper is set to, you shouldn’t get a waft of diesel smell.