The intercooler on my Golf 4 has been dripping oil for a while. Lately it also developed a whistling noise. Time to investigate.
The plastic cowl presses against the aluminium intercooler and after about 400 000km, wears right through the aluminium.
Replacing this thing is a bit of a pain in the arse. According to Haynes, the front bumper and right-hand side headlight has to come off, and that’s the way I did it. But I suspect one might be able to do the job by pulling the windscreen washer bottle instead.