My Jaguar was parked for a good 4 months and during that time it leaked out all the transmission fluid. I put a few quarts in it and finally it moved. Is the leak a major problem that will cost a ton of money to fix? I know nothing about cars but this car was a gift from my now deceased stepdad and I want to keep it.

 

OK, first things first.

You are new, so welcome to our side.

Second thing. The 1990 XJ6 is known in Jaguar world as an XJ40, confused, good, so were we in the early days.

Hopefully one of the Mods lurkng in the background will see this and move it for a NEW member. They have been a tad slow at this lately, so it may be benificial for you to repost this in the XJ40 section, so you get more precise answers.

To drain ALL the fluid is a tad dramatic I think. That would be something like 12ltrs of fluid. I reckon you got about 2-3 ltrs MAX, drained out via the selector shaft seal, on the side of the trans casing. It looks like a LOT due to its ability to "spread" and appear massive. This is kinda common after sitting for that amount of time. The convertor drains back into the pan and overfills it, and if the small selector seal is worn, out it comes.

You have a ZF 4HP24 transmisssion, and I have heard very little of oil leaks from them, so I reckon a raising of the beast and go under and look see is in order.

Others will chime in with suggestions from the XJ40 area once they pick up on it.

 

I run into this all the time with stored cars. If you plan on driving the car regularly the problem might well fix itself.

No, a leaky seal or gasket cannot be cured by anything but replacement. However, it takes a few days of non-use for the torque convertor to drain down. If the car is used (or at least started) every few days, the symptom will probably go away or be minimalized.

Cheers
DD