116i, engine malfunction, fault code 2A99
I recently bought a used BMW 116i a month ago from a independent dealer, made in 2009 (59reg), with 33,500 miles. I did not drive the car often, normally 2 days a week. Recently, I got some problem with it. The main one is the Engine malfunction sign in yellow popped out. It happened about 3 or 4 weeks ago, but not any more since the weather was getting colder here in the UK. The sign popped out for about 6-8 times during a 3-4 weeks period, shortly after I bought it from a dealer (not BMW dealer). It normally happened in the morning after I drove the car for about 5 minutes, and I did not notice any power reduction, and after I restart the engine, the sign will be off for the rest of the day. I sent the car to 2 garages to check, they only found one fault code: 2A99, Crankshaft - Outlet Camshaft, Correlation and I was told that most likely it is the timing chain failure.
I read some posters online, and people are saying that there are a number of possible causes for this fault code, such as coin pack, vanos unit, vanos solenoid, HPFP etc. Apart from the malfunction sign, the car is running fine, no strange noise and no reduced power, how likely do you think there is a failing timing chain?
Please help. I need to confirm to the garage whether or not to open the engine to further check it, which is a 3 hours' work. Thanks.