SOLUTIONS: Petrol smell in boot and in car
Posted: Thu Oct 04, 2018 9:34 am
Good morning,
Just wanted to update everyone on my recent findings when trying to cure petrol smells in my +2.
I assume it is a very common problem (at least in the boot) but would be interested to hear from anyone who has a fresh smelling boot!
Research on various forums has led me to the conclusion that many old rubber hoses display high levels of permeation (fuel vapours pass through the rubber without any visible signs of leaks). This situation has been worsened by changing composition of modern unleaded petrol.
The attached screenshot is from the (old) SAE J30 specification for fuel hoses and shows the allowable Permeation of a new fuel hose for various specs, R6, R9 etc.
As you can see a R9 hose will allow only 15 g/m2/day versus 600 g/m2/day for a R6.
Assuming your boot was full of R6 hoses you could cut the fuel smells to 1/40th by switching to R9, thats not even taking account of the degredation in performance of older hoses.
In the last year I have replaced and upgraded the following hoses with BioFuel rated hoses (supposedly even better than R9):
Engine breather hoses
Oil Catch can hoses
Fuel tank breather hoses
I have also replaced:
Fuel Filler Elbow
Fitted new Newton inline breather vent valve
Replaced fuel filler cap gasket
This has now doubt made a huge improvement but I was looking for perfection. The cockpit is a lot less smelly but the inside of my boot still smells.
I have an instrument at work which detects vapours and gives a readout in ppm (parts per million) or ppb (parts per billion), so I decided to use it to identify the source of the smells in the boot.
The zerod the instrument in the car park
Background level in boot was less than 1ppm
When i placed the instrument near my new breather hoses there was a small rise but not huge.....good news, they were working well.
BUT my fuel filler elbow and braided fuel injection supply and return hoses were all showing very high levels of permeation, the instrument showed levels of up to 100ppm when placed near to any of these hoses! The braided fuel injection hoses were approximately 6 years old, the fuel filler elbow only 1 year old and was supposedly high spec from a small rubber supplier I contacted.
In an ideal world I would replace all of these hoses with a higher specification but I think the biggest gain can be made from replacing the fuel filler elbow.
Not only is the filler elbow subjected to fuel vapours, it also has fuel sat in it and it has by far the largest surface area of all the hoses which means it is probably the worst culprit.
Solution?
Everyone looks to their breather pipes to fix fuel smells which is a good idea, especially if you still have them running through your headining. But I would suggest the filler elbow would also be a very good place to start.
I would like to replace the 57mm fuel filler elbow with either a high spec rubber (R9/Marine A1/ Biofuel grade) hose or a metal elbow. The prblem with a metal elbow being that rubber joiners are still required.
High spec rubber would be my preference for ease of fitment but Im struggling to find such an item available, I dont believe any of the filler elbows commercially available are low permeation when subjected to fuel constantly sitting inside them.
Sorry I havent provided a complete solution but I hope this thread will be of use to some of you trying to make similar improvements?
Perhaps if there was enough interest we could find a rubber supplier who would make a high spec filler hose?
Thanks
Gav
Just wanted to update everyone on my recent findings when trying to cure petrol smells in my +2.
I assume it is a very common problem (at least in the boot) but would be interested to hear from anyone who has a fresh smelling boot!
Research on various forums has led me to the conclusion that many old rubber hoses display high levels of permeation (fuel vapours pass through the rubber without any visible signs of leaks). This situation has been worsened by changing composition of modern unleaded petrol.
The attached screenshot is from the (old) SAE J30 specification for fuel hoses and shows the allowable Permeation of a new fuel hose for various specs, R6, R9 etc.
As you can see a R9 hose will allow only 15 g/m2/day versus 600 g/m2/day for a R6.
Assuming your boot was full of R6 hoses you could cut the fuel smells to 1/40th by switching to R9, thats not even taking account of the degredation in performance of older hoses.
In the last year I have replaced and upgraded the following hoses with BioFuel rated hoses (supposedly even better than R9):
Engine breather hoses
Oil Catch can hoses
Fuel tank breather hoses
I have also replaced:
Fuel Filler Elbow
Fitted new Newton inline breather vent valve
Replaced fuel filler cap gasket
This has now doubt made a huge improvement but I was looking for perfection. The cockpit is a lot less smelly but the inside of my boot still smells.
I have an instrument at work which detects vapours and gives a readout in ppm (parts per million) or ppb (parts per billion), so I decided to use it to identify the source of the smells in the boot.
The zerod the instrument in the car park
Background level in boot was less than 1ppm
When i placed the instrument near my new breather hoses there was a small rise but not huge.....good news, they were working well.
BUT my fuel filler elbow and braided fuel injection supply and return hoses were all showing very high levels of permeation, the instrument showed levels of up to 100ppm when placed near to any of these hoses! The braided fuel injection hoses were approximately 6 years old, the fuel filler elbow only 1 year old and was supposedly high spec from a small rubber supplier I contacted.
In an ideal world I would replace all of these hoses with a higher specification but I think the biggest gain can be made from replacing the fuel filler elbow.
Not only is the filler elbow subjected to fuel vapours, it also has fuel sat in it and it has by far the largest surface area of all the hoses which means it is probably the worst culprit.
Solution?
Everyone looks to their breather pipes to fix fuel smells which is a good idea, especially if you still have them running through your headining. But I would suggest the filler elbow would also be a very good place to start.
I would like to replace the 57mm fuel filler elbow with either a high spec rubber (R9/Marine A1/ Biofuel grade) hose or a metal elbow. The prblem with a metal elbow being that rubber joiners are still required.
High spec rubber would be my preference for ease of fitment but Im struggling to find such an item available, I dont believe any of the filler elbows commercially available are low permeation when subjected to fuel constantly sitting inside them.
Sorry I havent provided a complete solution but I hope this thread will be of use to some of you trying to make similar improvements?
Perhaps if there was enough interest we could find a rubber supplier who would make a high spec filler hose?
Thanks
Gav