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From The Saab Tech Wiki
===Access===
The timing chain tensioner is located on the passenger side of the engine. The airbox, serpentine belt and upper idler pulley were removed to get good access with the tools on hand, and to see better. Removing the tensioner with all other parts in place is possible, but more difficult.
[[file:900_9-3_TC_Tensioner_1.jpg|thumbnail|none|Fig. 1 - Timing Chain Tensioner Location]]
===Close-up===
Tensioner position behind idler pulley. The picture shows the tensioner housing with the off-center spring retaining cap at the end. The pulley was also removed because the pulley bolt did not allow enough clearance for the 27-mm socket used on the tensioner housing. A standard socket may be a better fit than the long socket shown below.
[[file:900_9-3_TC_Tensioner_2.jpg|thumbnail|none|Fig. 2 - Timing Chain Tensioner Location Close-up]]
===Removal===
The 12-mm spring retaining cap must be removed first, otherwise the tensioner will extend fully while it is being removed! The spring and plastic pin come next. The tensioner housing is taken out last. It can take a fair amount of force to break the housing loose, then it can be unscrewed by hand, carefully to keep the tensioner pluger from moving.
[[file:900_9-3_TC_Tensioner_3.jpg|thumbnail|none|Fig. 3 - Timing Chain Tensioner Retaining Cap Removal]]
===Components===
e - tensioner housing
f - tensioner plunger
[[file:900_9-3_TC_Tensioner_4.jpg|thumbnail|none|Fig. 4 - Timing Chain Tensioner Components]]
===Extension Measurement===
The tensioner range is from about 8 to 18 mm (9 or 10 clicks). Maximum extension on a normal older engine is probably between 11-15 mm. Mine was extended to the limit, which explained the chain noise from the timing cover.
[[file:900_9-3_TC_Tensioner_5.jpg|thumbnail|none|Fig. 5 - Timing Chain Tensioner Extension Measurement]]
===Wear Marks===
After a little cleaning with a rag and a brush, marks can be seen on the back of the shaft, showing how the tensioner took up the slack as the timing chain stretched. 10-11 marks are visible, so the tensioner started at 7-8 mm and slowly extended to 18 mm over the life of the engine, before it could no longer keep the chain tight.
[[file:900_9-3_TC_Tensioner_6.jpg|thumbnail|none|Fig. 6 - Timing Chain Tensioner Wear Marks]]
===Reassembly===
First the latch on the tensioner housing is pressed down and the plunger is pushed in to reset the tensioner. After that, re-assembly is in reverse order, tensioner housing first, tighten to 47 lb-ft, then the cap and spring with pin inserted. As the cap is screwed in, the spring tension pushes the pluger out to take up slack in the chain.
