How to fix "Whooshing" Fuel Tanks in Series III XJ6 Jaguars

Jaguar Parts Technical Information

The Series III XJ6 Jaguar has a fuel vapor recovery system, which captures excess fuel vapors inside the charcoal canister located in the front right fender. Sometimes this system gets clogged or a pressure valve malfunctions, leading to a substantial vacuum in the fuel tank. The most noticeable symptom is a whooshing sound when you open the fuel tank filler caps. This whooshing sound is bad news. The vacuum builds up in the tank until the sides of the tank suck in a little. Then, when the filler caps are opened, the fuel tank expands back out.

You can sometimes hear the tank popping back into shape. Do this a lot and the tank will crack from the flexing and start to leak. The usual suspect is a little valve right next to the charcoal canister, inline with a rubber hose leading to the canister. When that valve fails, the vacuum builds up. The only fix for this is to replace the valve. The pressure valve is no longer available new but we do have tested used ones on the website under part number CAC3101-USED.

See our Jaguar Parts Store Catalog to order parts.

Other Jaguar Technical Information Pages:
TechBits Page 1   |   TechBits Page 2   |   TechBits Page 3

Can't find the new or used part you need? Complete the Jaguar Parts Request Form:

If you have any questions, just email us.

Return to JAGBITS home. is an independent parts distributor and is not authorized or affiliated with Jaguar Cars Limited. Jaguar Cars Limited is the owner of all JAGUAR, JAG, and model name trademarks