Some of you may remember the problems I was having with my 159SW - Check this thread if you don't - http://www.alfaowner.com/Forum/alfa-...ower-loss.html
Finally got her back today - running as it should ! It has taken nearly 7 months - mainly because it was being done by a friend in his spare time - but also partly due to the problems we have had identifying the issues it had.
Anyway, here is a list of the problems it had - all connected - it is believed that a blocked DPF was the root cause, sending excess carbon into the inlet manifold. This caused the swirl flaps to gum up to the point where they became loose off the pivot rods, eventually causing the flaps to disappear down the inlet manifolds when the carbon gave way. This in turn caused damage to the inlet valves, piston heads and turbo. Part of the reason finding the problem took so long was due to the fact that the car drove like it had a blown turbo, but displayed none of the classic symptoms of turbo failure, other than a lack of power.
So, the listed parts were replaced, in list order - due to the strange symptoms, it was assumed at first to be an electrical fault (possibly faulty sensors) so this is where the works started. It was only after the inlet manifold was removed (at my request) for cleaning that the missing swirl flaps were noticed leading to the turbo being removed for inspection ( damage found) in turn, leading to the cylinder head being removed and the valve and piston damage being found at that point.
However, having had all this work done and new parts fitted where needed, there was still a power loss and still warnings and fault codes popping up. One of the fault codes was pointing to a faulty DPF temp sender - another to a faulty differential pressure sender. On checking the Differential Pressure sender (pulling rubber pipe off DPF can) it was noted that there seemed to be far too much pressure being blown out through the metal pipe that the rubber pipe was removed from. The Pressure sensor itself tested and appeared to be working fine. This prompted an attempt at a Forced regen, which failed, so the DPF was removed for inspection. This was sent away for cleaning in an UltraSonic bath. It was refitted upon its return and the car was abolutely transformed - however, there now showed a fault on the DPF Temp sender. This was replaced, and now as I type, everything seems fine with the car - fingers crossed !
MAP Sensor .
EGR cleaned and tested.
EGR blanking plate fitted.
Inlet manifold removed and cleaned.
New Turbo fitted.
Cylinder head recon including 5 new inlet valves.
Umpteen runs on the Diagnostics trying to figure it all out.
Cam and PAS belts were replaced as head was off.
Water pump replaced as belts were off.
DPF Ultrasonic clean - core removed for cleaning then refitted into original can afterwards.
DPF Temperature sender replaced.
Still waiting for the bill, but nice to have her back !