Just wondered if anyone can provide any advice on overboost fault code 16618.
My 2006 (55 plate) A4 2.0 TDI S line Avant has had a series of problem since purchasing it in October, with the following remedies taken so far.
My mate is having it back in for a look tomorrow, but in the meantime, can anyone give us any further advice or a steer on what it could be or what else to check? Im getting a bit hacked off with the Audi i bought for reliability, and need it sorting before i go back to work and start putting the miles on it again next week! Any help would be massively appreciated, thanks in advance.
- Blown pipe on EGR - Replaced with new EGR cooler by an independant Audi Specialist in Novemeber, no further issues.
- Intermittent loss of boost (and power) and occasional black smoke week before xmas - got permanent fault codes for MAF, and glow plugs. Replaced full set of glow plugs and new bosch MAF. Ran fine for short period, then same problems returned.
- Looked at EGR valve bit carboned up, and flap was stuck and snapped off the shaft - EGR valve replaced last week. - ran ok for a short time, then keep getting loss of boost, no smoking however seriously down on power, and got engine light on dash - just been to have fault codes read again, and its giving the 16618 overboost fault. Car run ok(ish) for a while after switch off/ restart but then boost drops right off again. Also, after a restart, whilst boosting getting a slight but distinctly noticeable dump valve style flutter when come off the throttle, which isnt normally there. We have looked at the turbo, vanes all seem to be free and fine, actuator lever for the vanes seems to be working ok.