The 159 is now a fairly regular visitor to our workshop and it is a very reliable car and we dont generally have many issues with it but you would be well advised to check our general tips on buying any used car by following this link which will also be of some help if you have found a used 159.
Plus our Alfa 159 Review page contains useful information about the model history.
The first and most serious issue is the extreme appetite for front tyres, they seem to wear on the inner edge with alarming speed, sometimes in under 10,000 miles and this is nearly always a geometry issue and it also makes the car feel as though it tram lines on anything from white lines to the ubiquitous lorry ruts and it is fairly easy to improve simply by setting the front tracking up correctly you will alleviate the issue and bring back some of that Alfa feeling. The other issue with front tyre wear is caused by wear in the upper top wishbone and while it is no where near as much of a problem as it was with the 156 there is still a chance that the bushes are worn. Wear in the 159 front upper wishbone is usually accompanied by a rattle but it is extremely difficult to pinpoint where on the car the rattle is coming from. So if you have a rattle that you cant precisely pinpoint then it may well be the upper wishbones at the front.
On the 2.2 litre JTS engines there is an issue with the engine management light coming on and when you read the fault code it tells you that the camshafts are incorrectly timed and this is caused by a stretched cam chain, they don't seem to break, thank god, but they do make the dash light up like a Christmas tree. Unfortunately there is only one cure for this which involves replacing the camshaft drive chain and this takes around 4 hours and the 159 cam chain kit will cost around £300 so it is not a cheap fault to rectify. On the old four cylinder Nord engine the chain also had a slight tendency to stretch but it is a duplex chain and so wore a lot less and it was possible to adjust the camshaft timing using the verniers on each camshaft drive pulley, It did however manage to make a distinctive rattling sound and wear itself into the engine casings to warn you that there was a fault.
The Diesel engine in the 159, while it is probably the best engine that is fitted to the car, also has its fair share of issues three of which are going to be covered here, the first of these is the perennial problem with the Exhaust Gas Recirculation (EGR) valve, this either sticks open or just sticks and then all the air pressure that is provided by the turbo charger is simply bled off into the exhaust system. This gives quite a distinctive driving fault which means that the power will only come in over 3000 rpm when the amount of air the turbo can compress exceeds the amount of air that can be bled out of the inlet manifold and so you get quite a power hike as you go through 3000 rpm. You do however have to be a little careful as a faulty air flow meter can also give the same symptoms on occasion although a faulty air flow meter will usually give power low down with no top end power.
The next problem with the diesel engine is the water pump bearings, these have the nasty habit of seizing up which would not be an issue if they didn't run on the back of the cam belt which then snaps, however this is not all quite as bad as it could be as on the Mjet engine the camshaft does not run directly on top of the valve instead it has a small rocker and these tend to break before any major damage is done to the valves. If the cam belt does break the broken rockers can be replaced by removing the cam carrier and leaving the cylinder head on the car and you will usually 'only' end up with an invoice of around £1000 or below. When the belt does break you do need to set up the camshafts correctly as there is no keyway to keep the cams located and they do have a habit of moving when they get such a hammering.
The most serious issue we are having is with the front sub frame corroding, some of them are even getting holes in them which is causing the car to fail the MOT and changing the front sub frame is a very time consuming job as everything seems to attach to it and at around £1500 it is also very expensive! Now for a little TLC this cost could be avoided, all it needs is a can of wax oil and a wire brush and in an hour it would be problem solved and summer is the time of year to do it after we have had a week or two's dry weather it is perfect, It is best to do the whole sub frame but it is only the part that comes in contact with the undertray that really suffers so if you could at least do that it would be good.
The 159 also has a tendency to eat rear window mechanisms, fairly obviously this does not apply to the Brera, now as the front and rear window mechanisms are virtually the same but we have very few issues with the front windows, the reason for this is simple the rear windows never get used so they seize up, well the simple cure to this is to use it more, every time you use the front windows wind the rear ones up and down at the same time and you will not have a problem.
Another problem you get with these which unfortunately I have no easy remedy for is the gearbox, this gearbox has issues with the bearings in the end case. They wear out and I suspect that this is a design issue which I don't think changing the oil will help but it it cant harm so it may well be worth doing. Now the trick with the gear box bearings is to catch the problem before the bearings seize and the bearings outer case spins in the bearing housing as that is where this becomes really expensive, so if you hear a bearing noise which is only apparent in the upper gears it is better to get it seen to sooner rather than later.
Finally we have the saga of the inlet manifold which for once Alfa Romeo seem to have done a slightly better job than their rivals BMW and Mercedes. In the inlet manifold there are either 8 or 10 separate tubes that feed each of inlet valves separately, on one of each pair of tubes, which feed one cylinder there is a flap like a throttle butterfly that opens as the power demand increases. The idea of the flap is to improve the combustion of the fuel by creating swirl in the combustion chamber at low revs (not a new idea see the 33 1.7 16 valve), so the flap closes at low power demands and opens as you need more power. On Alfa Romeos this flap has a tendency to jam and bring up a fault on the engine management system and the engine will then only produce minimal power which is barely enough to drag the car up to 50 MPH. Luckily on Alfa's unlike their rivals the flaps don't get separated from the spindle and then get dragged into the engine which can cause the engine to destroy itself. Unluckily for Alfa owners it is a right pain to change the manifold as you have to remove the cam belt and fuel injection system high pressure pump which can take the best part of a day and the 159 inlet manifold itself is over £250 so that is not a pleasant bill to get at any time.
While all this looks fairly horrible the instances of problems with the 159/Brera are fairly rare and with the advent of the new generation of small capacity petrol turbo engines at least the stretchy timing chain issue is no longer there.