Hello all, my C280 has been making a loud whiny fan noise on startup for a while now, and it seems to be getting worse. It only lasts for about 5 seconds or so, and only as the car is being started cold. Very hard to for me to diagnose by myself in that short time frame.
Second issue is that it surges at idle sometimes, and seems to have more power at high speed between 50-70% throttle than at full. This started just after installing a K&N air filter. Seems to me like the car's not compensating for the extra air, and it's making the mix lean. Anyone know how to adjust for this? Thanks!

Andrew
'67 250S
'69 220D
'84 190D
'95 C280