ok so oil cooler thermostat gasket was replaced, valve cover and upper timing chain cover gaskets were replaced as well. I am still seeing oil collecting at the bottom of the diff. where the heck is it coming from? :) .. it's like a drop of oil hanging and ready to fall on my garage floor .. so not a heavy leak but oil is leaking from somewhere. any idea? much appreciated!

Is it clean fresh oil or dark nasty stuff that could be from the previous leak?

Spray it off with some degreaser and wait and see if it comes back. It is hard to get all of the oil off from an engine when there has been a leak so it could be a remnant....

Hopefully it isn't the oil pan... That would require a full front frame drop and removal of the front axles to fix ~$50 in gaskets...

-Rich

I did clean the old oil very well. Everything looked nice and dry. I also changed oil so the oil on the diff looks new oil (golden color). Would an oil pan gasket leak collect at the bottom of the front diff?

It could. Oil tends to run down things and collect at a low point. I would double check the VC gaskets by wiping along the edge with a clean paper towel to look for leaks.

I just did an engine swap and redid all of the gaskets on my 4.8i so it is somewhat fresh in my mind... :)

Is it definitely engine oil or could it be power steering fluid? Genuine CH11s is green when new but Febi and some others is not very green and the green seems to fade over time. Power steering leaks can come from the lines or potentially from the rack (although that was more of an issue on my e46s).

If you changed the diff oil then the process is to add it until it overflows much like the transmission so it could be just spill over that is just running downward.

Do you have any other spots or oil run lines on the belly pan?

If everything is clean and dry then you should be able to track it down (not that there is any room to see anything in a 4.8i e70).

-Rich

I changed the engine oil. But thanks for the tips. I will take a closer look.

Anyone have a parts list for this repair?

N62 4.8 Oil Thermostat Gasket Leak (2007 X5)
 

It’s just the alternator bracket gasket. It is good to replace the two o-rings on the oil cooler line as well while you are down there. Takes a few minutes. I had no problem reusing the bolts. Some replace the bolts with a hex bolt rather than the original torx bolts.

https://www.fcpeuro.com/products/bmw...yABEgI-2vD_BwE

https://www.fcpeuro.com/products/bmw...-17227800958oe



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Thank you for the info

Got it all buttoned up. Overall not too bad of a job. Took me approx 6 hrs. The only thing that I would add to the parts list is plastic rivets for the fender flares. I got to 3 of the bolts thru the wheel well so I had to drill out the rivets

Good job. From above it’s blind so it sounds like you got a good look. This job could probably be done in 3-4 hours if you ever have to do it again.


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