Difference between revisions of "NG 900/9-3 Drop the oil pan, inspect the screen"
(Dropping subframe to gain access to the oilpan for removal, inspection, cleanup and replacement)
Revision as of 11:35, 15 January 2010
The oilpan was removed after some minor signs of sludge were found during a valve cover removal and inspection.
List of tools
- Full metric socket set
- O2 Sensor socket
- Torx set
- Long (at least 24") breaker bar
- Adjustable wrench
- PB Blaster (or your choice of penetrating oil)
- Anaerobic sealant
- Degreaser (optional)
- Blue Loctite
- Hydraulic jack
- Ramps (jackstands can be used but you're going to be putting some serious torque on the subframe)
- Put the car on ramps, set the parking brake, put blocks behind the tires. I really can't emphasize enough how dangerous this may be to do on jackstands. Trust me, when it's time to try and get the middle subframe bolts off, you'll be glad it's on ramps.
- Remove all of the airshields.
- PB Blast everything: nuts holding downpipe onto turbo, front O2 sensor, all six subframe bolts, the small crack where the subframe meets the frame over the middle subframe bolt (so that it would flow down into the thread) and, finally, all of the bolts holding the oil pan on.
- Drain the oil and remove the oil filter.
Drop the exhaust
- Remove the O2 sensor and run it back up through the block to rest on top of the DIC.
- Remove the flange holding the downpipe onto the turbo. One nut on the bottom, two on top. Not much room to work on top, but no real problem.
- Consider removing the pipe that holds (held) your turbo silencer but it really isn't in the way that much. It may make getting the downpipe out easier though.
- Disconnect the cat O2 sensor and guide the wire down through the engine. There is a small ziptie holding it in place.
- Leave the downpipe on the bolts, release the hangers, starting at the front. You have a decision to make here. You can keep the exhaust hanging on the last set of hangers and push it to the side or you can remove the whole thing. If you leave them connected, you may damage the flex pipe.
Drop the subframe
- Starting at the front, remove the first subframe bolt on each side of the subframe. These two are easy to remove, not even requiring a breaker bar.
- The middle subframe bolts may prove to be very tough to remove. Be prepared to break a socket trying to remove the passenger side bolt. Though this may not be the case for everyone, it is difficult, if not impossible, to get these off without a breaker bar. At this point, you really will be glad the car is on ramps.
- Again, you have a decision to make; completely remove the subframe or leave the subframe installed with the back two bolts loosened.
Remove the oil pan
- Remove the bolts holding the oilpan on. It is a bit tight on the passenger side, requiring a little maneuvering around the subframe. There is a small cover over the flywheel that you must remove to gain access to two of the oilpan bolts.
- Place a hydraulic jack under the transmission and slowly jack the engine up to provide clearance for the oil pan between the engine and subframe. Do this from the safety of the side of the car, as this is a BAD time to be under the car.
- Tap the oil pan with a rubber mallet and the oilpan should come off.
- Dump the remaining oil out of the pan.
- Remove the oil pickup and inspect the screen. A little loose material is ok. A mostly clogged screen is not.
- You will likely find a fair amount of thick, almost sludgy oil in the bottom and corners of the pain. Carefully clean that out looking for real sludge, gasket material and metal shavings or pieces.
- Check out the bottom end. Again, you are looking for heavy varnish and sludge.
- This is really personal preference. You may use Simple Green or oven cleaner. Oven cleaner is pretty nasty stuff but it gets the pan really clean very quickly. Simple Green is less harsh but you are probably going to get busy with a wire wheel or steel wool and a lot of elbow grease with that option. It is very important to get the mating surface surgically clean.
- Apply a bead of anaerobic sealant/gasket maker to the pan, staying about 3/16" away from the inside lip of the pan. Let the pan sit until the gasket material loses its tack, about ten minutes. Clean the mating surface on the bottom end while you are waiting. Again, get the surface perfectly clean.
- Put the pan back on. Have bolts close at hand as the gasket maker will not hold the pan on the bottom end.
- Reinstall all of the bolts on the oil pan.
- Replace the cover on the fly wheel.
- Reattach all subframe bolts, using Loctite on the bolts.
- Rehang the exhaust.
- Reattach all of the O2 sensors.
- Put the downpipe back on the turbo.
- Reattach all of the air shields.
- Install the new oil filter.
- Wait for the sealant to cure, usually about 24 hours.
- Refill the oil (with synth of course!)
- Remove the fuel pump fuse and crank the engine a few times to get the oil circulating.
- Replace the fuel pump fuse and take her for a test drive.
This is a matter of some debate but it appears that the NG turbo cars seem less prone to sludging than the 9-3, 9-5 and Viggens. However, there are NG turbos that have sludged up and ruined the engine. So, for some, this will be a matter of curiousity and confirming that there are no surprises in the oil pan or bottom end. For others, this will lead to the discovery of large amounts of sludge and, likely, some headaches cleaning it all up. The process took me about four hours the first time but I have since helped another Saaber get his done in less than two hours.