CLK 209 - M272 noisy thing..

[Halcyon Days]

what I thought was the pulley wheel making a noise, I think is actually this round boxy tubey thing..
Anyone know
A: What is it?
B: What does it do?
C: is it user-serviceable to give it a clean? (In case it's got crud in there)

thank you

 

[Halcyon Days]

Ok, it's the "Secondary air pump"
for all your secondary air needs, I guess!!
how necessary is it? If it was to go bang, would it render me immobile?

 

[Halcyon Days]

I didn't get any success with this question..

I've disconnected it now, so far no check engine light... Do you think it will show up after a couple of cold-start cycles though?

I have a warrantee (RAC) on the car.. worth claiming for it, do you think? It's not a serviceable item.. and they're somewhat pricey to replace

 

[gazz]

It will put the light on eventually. Something tells me it'll give you twelve starts without a light, but the engine light will come on shortly after the thirteenth.

It is there to introduce extra air into the exhaust during cold start enrichment, and other times of rich mixture, to prevent your catalyst becoming a burned walnut.

 

[Halcyon Days]

Thanks Gazz
when the light does come on, will it induce "limp-home" mode?

 

[gazz]

Thanks Gazz
when the light does come on, will it induce "limp-home" mode?

No.

Was it running all the time? It's supposed to run for a short period, something like 15-20 seconds, then switch off. If it was running constantly it's quite common for the relay to stick. I'd recommend changing the relay if you are replacing the pump.

 

[Pitts Pilot]

How do I reset a re-map's 'learning' process after new exhaust?

Opps, intended a New thread

 

[Halcyon Days]

No.

Was it running all the time? It's supposed to run for a short period, something like 15-20 seconds, then switch off. If it was running constantly it's quite common for the relay to stick. I'd recommend changing the relay if you are replacing the pump.

No, just at cold-start for maybe 30 seconds.
Thanks for your help

 

[andy1964]

Hi guys

I here a high pitched fan sound on initial start up which I have not noticed before it goes off after about 20-30 seconds is this normal am sure it the secondary air pump.

 

[moosehead]

I have the 2.5L M272 and my air pump whines on initial start-up. I really don't think it's anything to worry about. Obviously it runs at a fair old speed and the engine always sounds a bit lumpy until it cuts out. I guess that's because of all the air it's pulling in.

 

[Halcyon Days]

Just had mine replaced.
it doesn't just pump air at start-up, it will also do it under heavy load.. So if it goes, the engine won't be fueling correctly.
I don't know if it is related, but my air mass meter was also throwing up a fault code, so that was replaced too.