GTR

Hey fellas,

Just wondering whether you can help me identify the part that's circled in yellow. I've diagnosed an engine whine on my 2008 C300 that appears to be emanating from this component, yet, I have no idea what it is.

Thanks!

AkaSigFreak

EMISSION SYSTEM / EMISSION SYSTEM / EMISSION COMPONENTS / A.I.R. pump
A.I.R. pump 3.0L & 3.5L

http://www.getmercedesparts.com/part...iagram=5777160

RLE

That's the air pump. Does it whine all the time or just after startup?

Glyn M Ruck

Excess air pump. Should shut down after warm up!!

Crippled

also known as secondary air pump too when searching on some sites.

GTR

Thank you for your responses, guys.

AkaSigFreak, are you a tech by any chance?!

RLE, it whines only when throttle is being applied and seems to be most prevalent around the 1500rpm to 3000rpm range.

Glyn M Ruck, I cannot ascertain whether the excess air pump has shut down after warm up, but the whine is there when the engine is cold and when warmed up.

Does anyone know what the implications are for a failed excess air pump and how much it would cost to replace?

AkaSigFreak

I am definitely NOT a tech.

[ 1 ] EMISSION SYSTEM / EMISSION SYSTEM / EMISSION COMPONENTS / A.I.R. pump a.i.r. pump 3.0L & 3.5L Online Price $521.25

Glyn M Ruck

I'm not sure it has failed. Rather that due to a sensor input or whatever it is not shutting down. I know this is going to cost but you need to get the car onto a Star DAS to diagnose what is going on.