Petrol smell

[peters3103]

A mate bought a 74 Series 3 OTS about a year ago. While driving at highway speed and accelerating and decelerating there is a strong smell of petrol. On a steady throttle the smell dissipates. He’s had two Jaguar specialists look at it and go over the fuel system checking for leaks without revealing anything obvious. It makes no difference if the tank is full or near empty. The car is almost unbearable to drive with the hood up as the fumes get trapped in the cabin causing eye watering. Tried driving today with petrol cap off with no change.The cap is non-vented.
Any suggestions appreciated.

Cheers,
Pete

[H7OB]

Hi Pete. My two sources of the smell of petrol were weeping banjos on the carbs and a loose jubilee clip on the fuel filler, accessed through the LHS cover in the trunk. You may well have checked those but they are both sources that I think need checking periodically.

Good luck. A constant smell of petrol is not fun.

[MarekH]

Two lines of attack:-

Firstly, a non-vented cap is only consistent with the petrol vapours being recycled into the charcoal canister and into the carburettors. See the tan coloured owners manual for how that system works and the Parts Manual for how it is plumped in. Otherwise a vented cap is needed.

Secondly, a rich mixture out of the exhaust pulled back into the cabin will have the same effect. Check previous archives for how to get rid of exhaust gas smell using grommets in all of the right places.

Gases always travel from a high pressure region to a low pressure region so you need to identify where the pressure is the highest and not give it a path to the low pressure region. My OTS had fibreglass wadding in the rear wheelarches, presumably for just that reason.

kind regards
Marek