Saab 93 Automatic died when waiting for traffic light and won't start again

Question

I just bought a 2006 Saab 93 Aero 2.0T automatic in October, 72000 miles. Everything seems perfect. But 2 weeks ago, the engine died while I was waiting for red light in the town centre, I just braked and waited and did nothing, then I felt the engine shake for 10 seconds, then it suddenly died.

I called the RAC to tow my car to my house (it was 8pm), they replaced a new battery for my car because the old one was broken, then I could start the car again. However, 2 hours later, I drove it to Tesco, it could not be started again when we want to leave. The RAC came again and could not find anything wrong. They towed my car to my house again. 2 minutes after they left, I just went to try and it could be started...

I did a full service at charnwood the day after. Everything was fine for the next week, until 4 days ago, the same thing happened when I was waiting for another red light. I called the RAC again, and 10 minutes after the call I tried to start it and I made it. Yesterday I went to another garage, and they said they could not figure what exactly wrong with my car. both times happened on rainy days. Could any one please tell me what I should do?

Answer 1

You have what in polite terms is known as an intermittant fault. Things like fuel pump or it relay, crankshaft sensor or some other component is failing to operate when warm, or even a loose connection somewhere. What I have had some success with on this type of fault is a data logger. (The RAC would have scanned your vehicle and found no faults.) A data logger can be left connected to your DLC plug and will record all of the engines operations on a 24hr cycle repeatedly. Should/when the cutting out occurs again, you can look at the data logger recording and usually find out why it did so. Launch CR recorder or OBD2 recorder are modestly priced and well worth while as data logging is not all that they do.