mazdeuce wrote:
I'm glad it's working out! You should start a build thread. We have a lot of them that are more like ownership logs than build threads and they work like a repository of information and experiences on a particular car and that helps the community learn about cars that we don't otherwise have a lot of information on.
I'll keep this thread going as my information repository for all things CTS Sport Wagon.
The 50,000 miles service is supposed to include changing the fluid in the transfer case and front and rear differential. The guy at the dealership where I bought the car had no idea whether it had the 50,000 miles service performed or not, so I decided to do it.
MY local Cadillac dealer quoted me $600 for the job, and my local quick lube wanted $400. Nope, I'll do it myself. There isn't much info on the web about performing the CTS4 (all wheel drive) specific maintenance, so here you go:
Once I got the car up on jack stands, I was pleasantly surprised how clean and rust/corrosion free the undercarriage was!
The rear differential is very simple. Both the fill and drain plug are out in the open in obvious places. Both take a 10mm allen wrench, and there's plenty of room to work.
The front differential is slightly trickier. The drain plug is right in the middle of the bottom and easy to get to. The fill plug is on the back of the differential, above the K-member, and in front of the exhaust. Your best bet is to use a 10mm allen on a ratchet with a long extension so that your ratchet can be behind the exhaust.
Fill plug removal:
Filling with new fluid:
The transfer case is the hardest part. The manual says to remove the exhaust and the transmission cross member, then drop the tranny and transfer case. Nope, not going to do that.
Both the fill and drain plugs on the transfer case are square 3/8'', so a standard 3/8'' drive extension fits. This works great for the drain plug, but there's not enough space to get a ratchet up to the fill plug. I have a stuby 1'' long extension, and that's even too long to fit in the tight space.
It turns out that a 9mm allen wrench also fits pretty well. I cut the ball end off of an extra 9mm allen wrench I had:
This tiny allen wrench stub just barely fits into the fill plug and can be carefully turned with a small wrench (I taped my allen wrench stub to my wrench because it kept popping out):
Fill the transfer case VERY SLOWLY. There's something inside the case right behind where the fill plug goes, which prevents you from inserting the fill tube the whole way into the transfer case. If you pump too quickly, the fluid won't have enough tine to drain down into the case and you'll end up dripping it everywhere. Pump slowly!
A known issue with direct injection motors is carbon caking on the intake valves. The best solution to this seems to be installing an air/oil separator inline between the valve cover breather and the intake manifold.
The stock tube is a hard piece of molded plastic. You must remove it from the valve cover first, by pressing the tiny button and pulling on the fitting. After getting the tube off of the valve cover, remove it from the intake manifold. Its a 1/4 turn fitting on the intake manifold, hence why you needed to remove the other end first.
I cut about 8'' out of the stock hard tube, and added in a length of flexible 3/8'' fuel line on either side of my JEGS air/oil separator. The separator is pretty small and light, so i mounted it by zip-tying it to a rigid line.
I also replaced the stock air box and air tube with a cold air intake from Airaid. This seems like a very high quality kit and installed easily. This kit usually retails for ~$350, but I found the "carbon fiber" model on Amazon for only $185, so I bought it. I wanted the all black kit, but Amazon's price was too good to pass up. The fake carbon fiber finish is really cheesy, so at some point in the future I'll remove it and paint it gloss black.
Now I'm off for a test drive. I'll report back after I put some miles on it as to how much oil my separator collects and if the cold air intake improves my MPG.