Good evening all,

I've just purchased my 2004 Disco. It has a 4.0L Bosch engine swapped into it by the previous owner. I'm intending to LS swap it as soon as possible. I've noticed this sort of whining noise that tracks with the increase/decrease of the RPMs additionally I found a permanent DTC for 4th gear ratio incorrect. The car will also stall out when its up to temp and I stop at signs or lights or when I go to reverse out of parking spots. but all eccessories remain on. I'm thinking the torque converter is kaput and possibly 4th gear itself or the related sensor. This is my first disco but not my first rodeo, I have just never heard this sound before and want to confirm whether it's just a Disco sound or something nefarious, there is also the tapping noise that I assume is a lifter failing. Attached should be the video and a picture of the disco. Thanks!

 

probably transfer case - check fluid level but it just might be worn out

 

That might explain the oil slick I see on the underside of the TC, I do know the rear main seal is also leaking and was just hoping it was from that. These transmissions and transfer cases are said to be pretty tough no? Thanks for the insight.

 

Noise sounds like slipped liner, not urgent if you are doing an LS swap. TC could be leaking, wouldn't hurt to check but I would get one of these first: https://extinctmotorsports.com/land-...l-sight-glass/ Some whining is normal for tcase. Could also be PS pump or something else underhood. Maybe remove serp belt and see if whining goes away. Since it is your first, suggest you read ALL the stickies at the top of the forum. Rear main seals very rarely leak, I wrote a long post on why. More likely valve covers or rear cam plug. PCV mod is first thing to do to control oil leaks.