Cadillac CTS Starter Motor Replacement

The CTS is back! I really do love this car and it’s a pleasure to repair things like the starter motor which are normal and expected. There’s not much to this repair. However, as usual, there are a few tricks that will make your life easier. Follow along as we show you the main hiccups you are sure to encounter. The 3.6DI engine is a great powerplant and you should always be certain that she’s going to hum to life when needed.

Parts for this DIY:

• New Starter Motor (AC Delco 12644788 or Equivelant)

Tools You’ll Need:

• A Screwdriver Set
• A Ratchet Set with a Snub (Short) Ratchet
• A Jack and Lifts

First up you’ll want to crack the hood just to make sure you get a proper amount of light to the engine compartment.

Before doing anything disconnect the battery. The starter motor receives a live and constant feed from the battery so if you move the cable and it touches the car or engine it will ground and spark.

After Jacking up the CTS you’ll need to remove the lower trim guard to be able to access the bottom of the engine. This is the same as when you have to do an oil change. The plastic trim is held in place with 3 clips and bolts.

With the trim out of the way, you can now see where the starter motor is located. Unlike most typical GM V-engines, the 3.6DI had the starter motor on the driver’s side.  The motor is held in place with 2 bolts, which will have to be removed. You’ll also have to loosen the cable running to the battery and the electrical clip running to the ignition.

Before you do any of that though, you’ll need to remove the heat shield that protects the motor from the exhaust. The shield is held in by 3 side clips. To remove you basically pull it out from where it’s mounted. Don’t worry if it gets mangled a bit the shield is easy to straighten back out. This must be removed, if not there is not enough space to slide the starter out.

With the shield removed you can now remove the cable running to the battery. Just remove the bolt and slide the cable out. Fair warning, there is not a lot of slack in the cable. You might have to reach with your other arm further up the length and tug at it there in order to get the clearance necessary. It is definitely possible though.

Your next step is to disconnect and remove the small sensor located in front of the starter motor. This sensor is bolted to the block and will not allow you enough clearance to remove the starter if not removed. At this point, if you have small hands you can unplug the ignition wire running to the starter. If you can’t reach though, don’t worry. You’ll be able to remove it easily once the starter is hanging.

With everything loose, you can now remove the 2 bolts holding the starter. One on top and one below. Once loosened you can slide the starter forward and rotate it until it slides between the engine block and the exhaust. It is not the easiest fit but it will definitely slide out. If you hadn’t been able to remove the ignition line before you’ll have a chance after the starter is hanging down.

Before installing the new starter motor it is always a good idea to compare it to the old and make sure that they are in fact the same.

In this case, even though the part number was different, they were definitely compatible.

To install the new motor simply retrace the removal steps. The only part that might be a little tricky to reinstall is the heat shield, but it will go in with a little bit of manipulation. That’s all there is to it. Hopefully, you’ll have your CTS starting up reliably for the next 100,000 miles and beyond.