Saab 9000 Head Gasket

I got to work on another obscure European car, this time a Saab 9000. For a long time, this was leaking oil from the area between the timing cover and the cylinder head. As the leak got worse it started leaving small puddles of oil everywhere it was parked, so I finally had to do something about it.

The disassembly process was mostly straightforward - remove the exhaust manifold, remove the accessory drive belt, unmount the AC compressor and remove its bracket, drain the coolant, disassemble the intake manifold, unscrew the timing chain tensioner, and then remove the head bolts. With the cylinder head off, there doesn't seem to be anything amiss with the original gasket.

However, underneath the head gasket, the timing cover was not flush with the surface of the engine block. This was causing the oil leak. I should have taken a picture but oh well.

There were some additional things I wanted to do while the cylinder head was on my bench. It was fairly dirty inside, and I wanted to disassemble and clean it before putting it back on the engine.

I put the valves, springs, and lifters together on a sheet of paper to keep everything organized:

 

The intake valves were nice and clean, but the exhaust valves were a little bit dirty and pitted. I cleaned them in a wire wheel mounted in a drill, then hand lapped them in their seats:

After lapping:

 

 

I used a deep socket to push the new valve seals into place:

Reassembling the head was a bit tricky, since the valves and springs are pretty well recessed. I compressed the valves and fed the spring retainers into their grooves with a pocket screwdriver with a dab of thick grease on the end. The grease held the retainer on the tip of the screwdriver as I maneuvered the retainer onto the grooves on the valve. It was a surgical operation.

After scraping the head and block mating surfaces with a razor blade, I added a small amount of RTV silicone around the timing cover and installed the new head gasket:

After maneuvering the cylinder head around the timing chain guides, here it is back on the engine:

There are always some more "while you're in there" items to do on an old car with lots of miles on it. This heater hose looked pretty worse for wear, so it needed replacement. 

 

Saab, being the weirdos that they are, made a hose that's 5/8" on one end, and 1" diameter where it joins the head. This specific hose wasn't available, but Gates 19663 for a 1987 Ford Aerostar has the correct inner dimensions and just needed to be cut to length.

Several hours of reassembly later, everything is back together:

The worst part was dealing with the 3 piece intake manifold, since the bolts needed to line up exactly with their support brackets and many of them weren't in line of sight. The timing chain tensioner also has a rubber o-ring inside that needed replacement. I happened to have a viton 9mm inner diameter, 2.5mm thickness o-ring that fit perfectly.

Fingers were crossed, and after idling the engine for several minutes there is no longer an oil leak under the head:

Cheers!