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My SAAB 9000

I have been fond of Saabs for many years. I have owned a classic SAAB 900 Turbo and although it was a fun car to drive I found it noisy and I prefer the smoothness of the V6 engine. So when I got the chance to buy a 9000 3.0 V6 I took it. Its a great car to drive, well fitted, spacious and pretty economical at about 28 MPG (Imperial).

The beginning of trouble was early in 2002 when a lot of oil turned up in the coolant. I took the car to a Saab specialist that I had used before, on the South Coast of the UK. They changed the cylinder head gaskets, but after a short time the problem returned. At this point I took their advice and the engine was swapped for one from a wrecked car. The replacement engine was 50,000 miles younger than the rest of the car having covered only 35,000 miles.

In Dec 2002, to my horror, the problem returned. The engine was running hot, the coolant was full of oil that had been frothed up by the water pump and the flow through the radiator appeared to be restricted. The coolant had turned to a toffee brown yoghurt-like consistency. I was unwilling to spend much more money on the car but I was not at all convinced that the cylinder head gaskets were blown, as firstly there was no performance drop and secondly that the engine was so young.

I had a hunch that the oil cooler, which is immersed in a coolant gallery at the top of the block, in the 'V' between the two cylinder heads, was the prime suspect. If the oil cooler was leaking oil into the coolant, then that would explain the problem.

Unfortunately there isn't a Haynes Manual for the V6 varient of the SAAB 9000, so I used the Haynes Manual for the Vauxhall Omega which shares a virtually identical GM engine. I set about the strip down process to remove the oil cooler. This involved removing the air intake manifold assembly and retrieving the cooler from under the cover below the air intake. While I was doing this I also removed the radiator and filled it with petrol to dissolve as much of the oil that was blocking it as was possible.

These pictures show the view from the top of the engine between the two cylinder heads with the oil cooler removed. Some remains of the "toffee-yoghurt-like" oil/water mess can be seen in the gallery where the oil cooler is housed. The final photograph (© Haynes Omega Manual) shows the cooler itself.



I took the oil cooler to Valley SAAB in Coulsdon, Surrey and tested it for leaks with a high pressure air line with the cooler immersed in water. To my relief it did leak air, confirming my suspicions.

Rather than replace the cooler with a new one, as I suspect this is the second oil cooler failure, I decided to modify the design and fit an external oil cooler from a four cylinder SAAB 9000 in its normal position beside the radiator. On obtaining a used cooler (thank you Steve), I went in search of a hydraulic engineeering company to make some special pipes to connect the new cooler to the fittings on the V6 block just above the oil filter. I identified HCL Fluid Power in Croydon who kindly fabricated the new pipes for me. We decided to cut the original pipework and join the new hoses to it.

These pictures show the replacement oil cooler and the new pipes that I had made. Also visible are additional joints in the hoses at the far end from the oil cooler that HCL Fluid Power added in order to ease the installation process. When installed those joints are situated adjacent to the lower part of the air intake system adjacent to the air filter, which was also replaced as part of this rebuild process.

With a bit of adjustment to the position of the pipes, the new hoses were in place and the cooler fitted to the now flushed radiator. The auto transmission cooler part of the radiator was flushed with ATF to ensure no grit or debris that may have got in there remained.

These photo's show pipework beside the oil filter location, taken from below the engine where my new pipwork is fitted

The re-assembly process included replacing the thermostat, which is quite well buried under the air intake and renewing the various seals. I refitted the leaking cooler back to the engine but I sealed it by filling the banjo bolts with Araldite.

These photo's show the engine with the original cooler and the new thermostat ready for the air intake to be re-fitted.

Once the re-assembly process was complete the engine was turned over with the starter to bring back the oil pressure. I didn't want to engine to fire and run without oil pressure so this was done with the plugs removed to release the compression pressure and the fuel pump disconnected to avoid unburned fuel polluting the catalyst. I hoped that the Engine Management System would allow me to do this, with no plugs or fuel pressure. Fortunately it cooperated with what I wanted to do. The oil pressure came back quite quickly and there seemed to be no oil leaks.

On replacing the plugs with new ones and re-filling with coolant, the engine started fairly easily. No oil leaks of either engine oil or transmission fluid were found and the cooling system was bled of air. After a brief period of running a small oil leak in the new pipwork required a repair. The cooling system has been flushed three times with radiator flushing fluid. The GM V6 installation is notorious for air locks in the cooling system so the coolant needed frequent topping up.

The car is currently being run carefully, with daily checks on the water and oil levels and any traces of oil contamination in the coolant being syphoned off. These photo's show the reassembled engine.