We dont drive our 2005 XJ8 vanden plas much in the winter and have noticed that if it sits for 5-6 weeks in our garage it will start to leak transmission fluid. The garage is heated to around 50 degrees so its not like the car is frozen for weeks on end but I'm curious if anyone knows what causes this?

Thanks in advance!!

 

It is most likely the sleeve sealing the electrical connector to the transmission. If you try the search function on the forum there is all kinds of information available. Try the search term "transmission fluid leak".

You need to get the leak fixed reasonably soon to avoid a low transmission fluid level which will, ultimately, be fatal to your transmission.

 

Also check your transmission pan (plastic) for cracks. This might also be your issue when the trans fluid drains back into and fills up the pan with non use.. could also be the gasket.

When time to service change both the pan and the sealing sleeve and check the trans cooler lines for weeping at the crimp connectors..