Transmission and Differential Oils

When I had Randy do the rear subframe reinforcement, I supplied him with new BMW SAF-XJ in 1-liter bottles.  I had never seen these before and was excited to get them.  In reality when I picked up the car, I think the diff was loud.  So I have switched back to the Mercedes/Castrol 75W-140 SAF-XJ diff oil I buy from ECS.  You would think they work the same since they are both SAF-XJ, but they do not. 

Also, per the recommendation of a guy on Bimmerforums, I switched the transmission oil to standard Dexron III.  I used Motul, which is a higher end brand.  Previously I had been using BMW LT-2 but there is a theory that LT-2 causes the sticky shift pin issue.  Having replaced the shift pins on my S54, and knowing I don't want to do that job again, I am trying the Dexron III.  You cannot tell when you drive the car it is any different than LT-2.  Costs less too.

Refinishing the engine covers

The S52 (and I suspect, M54) engine covers rub against the underhood insulation.  All Z3s do it and this one was no exception.  Other owners report that you can use a silver Sharpie pen to fix it, but I went a different route.  When we got married, we made our own invitations with a tool called a brayer and imprint plates.  I used the same tools for this fix.  For the paint, I chose Por-15 Aluminum which is pretty much a dead-nuts exact match.

Por-15 High Temp Aluminum 8 ounces, $19.95r (Amazon)

iPod USB Bluetooth Audio

Outside of coupes, I am an audiophile.

I am slowly making the switch to high resolution audio on all of our devices at home and portable.  The X5 can read FLAC files off of a USB stick perfectly and the quality is obvious and fantastic.  Eventually, I am going to retire all of our iPods and replace them with FLAC, MQA, or other high-res capable devices.

I have not been happy with the sound in the coupenut car.  I recently set the gain on the amp to absolute minimum, and that helped tremendouosly.  But the real issue is at the source: the iPod.  CDs sounded much nicer.  To prepare for high-res, I changed out the CD changer-iPod adapter I had previously installed and I replaced it with a Grom USB3.  The advantage of the Grom is it has multiple inputs.  So for now, I can continue to run an iPod through it, but eventually I can run a straight 3.5mm headphone output from a high res device.  This means the DACs in the high res device do the work, not the Grom, not an iPod.  Also, the Grom unit has an optional Bluetooth adapter which is nice for phone calls and also streaming audio in a pinch.

I did but the Grom BMW trunk cable harness.  I didn't need a huge harness, but some extra slack is nice to relieve cable strain.

Grom USB3 = $149.99
Aux in and 5V USB charging cable = $14.99
Grom Bluetooth adapter = $49.99

Total cost of this mod = $214.97r