Now with your engine out of the car, it’s time to separate the parts.  With your SAAB 900 engine out, even if you are just replacing the transmission (yea, just), it is a prime opportunity to tear the engine down and reseal it.  There are so many small seals on the engine that are very difficult to get to with it in the engine bay.  By being opportunistic, you can save yourself a lot of headaches in the future.  Since I am planning on holding on to this car for a long time, I am going to disassemble and reassemble the car with it conveniently on the ground.  The following process can also be used with the engine still in the car if you are only working on gasket replacement, but as noted in Part 1, it is not too difficult to pull the engine on these classic cars, so whenever doing any major work on an engine with high miles, it can sometimes be easier to just take it out, make a weekend of it, and do everything at once.

Removing the head from the block

Before getting started, if you have readily available access to a high pressure hose, it’ll make the job much easier if you take the time to clean the engine and trans.  Douse it in cleaner/degreaser, let sit, scrub with a brush, and hose off.  Head overhaul can either be simple or complex depending on how far you want to go. Ideally, you would remove everything from the head (both external and internal parts), take it to a mechanic and have it hot tanked, plane the surfaces, and port and polish the valves before reassembly. Since my engine had such low mileage, I opted only to have it cleaned and planed, which will be necessary if you are doing a head gasket repair due to a blown gasket.

-Disconnect the idle control valve with its associated hoses and set it aside
-Disconnect all coolant, oil, and vacuum lines connected to the head
-Remove the fuel rail, fuel pressure regulator, and intake manifold (optional)
-Disconnect the upper turbo oil line
-Remove distributor (optional)
-Remove the exhaust manifold (optional)
-Remove the valve cover
Its a good idea to have a Bentley manual next to you for this next part, as it has far more detail on these next critical tasks.
-Set the engine to TDC (top dead center) by using the marks on the flywheel and cam gears
-Loosen the cam gears but don’t try to remove them yet
-Remove the cam chain tensioner from the side of the head.  If it comes out in one piece, measure how far out the plunger is from the body.  If more than 11mm, SAAB advises replacing the timing chain due to stretching.
-Now you can take off the cam gears, try not to let the chain fall down into the timing case.
-Using a breaker bar and reverse torx socket, loosen all 10 head bolts and set them aside in order
-There are two additional bolts on the bottom of the head attached to the timing cover, don’t forget those, they are hard to see!
-Lift the head out of the car, making sure not to get dirt or contaminates into any part of the engine.

With the head off, you can inspect your head gasket for points of failure. Typically the gasket comes apart around the coolant passages where it gets hot, or if the head warped due to overheating, the gasket between the coolant and oil passages may have failed. Check out this post for more info on head gaskets

Removing the block from the transmission

There is no tidy way to do this. My transmission mounting bolts were thoroughly buried in grime, and a scraper was needed to uncover them before removal. If your engine is out of the car, it’s obviously easiest, but I have heard of people removing the engine from the bottom. That process will not be covered in this post, as it is possible but not recommended (if you try, you’ll see why). I removed my engine and disconnected the transmission before lifting the block from it.

If you have not yet drained your coolant and oil from the engine and oil from the transmission, do that first…
-Remove the turbo support brackets if you have them
-Remove the 13mm nut from the stud located just to the right of the crank pulley (some replace this with a 13mm bolt before reinstallation)
-Remove all 16 bolts – there are three different sizes. The Bentley manual contains a diagram of where each size bolt goes.
-Lift the block from the transmission. This sometimes required a couple of taps with a dead-blow hammer or a light pry from a screw driver to separate the halves. Be careful not to cause any pitting or damage. Before you set the block down, there is an oil pickup tube that needs to be removed from underneath the block. It should be connected by two 13mm bolts and will slide right off.

Now your engine should be in three sections – Head, Block, and Transmission. It’s time to get to work to rebuild, repair, or reseal. Stay tuned for Part 3: What to Replace, or if you missed anything check out part 1.