E 39 Touring... secondary air pump
Discussion
Just had the Touring serviced and it came back with a report that the secondary air pump was not operating.
I understand that this item feeds air to assist cold starting/running...is this correct?
It seems like an expensive part to replace and to be frank I had not noticed it was broken. With this in mind is it worth replacing?
I understand that this item feeds air to assist cold starting/running...is this correct?
It seems like an expensive part to replace and to be frank I had not noticed it was broken. With this in mind is it worth replacing?
I think this is the hairdryer sounding device that sits in the drivers front wheel arch on my 540i.
As far as I know its for emissions, sounds illegal to me - blowing fresh air into the exhaust? I have no idea though.
I was once told that the units were un-fused and can cause fires if they fail?! Hopefully someone who knows what they are talking about will give you a better reply!
As far as I know its for emissions, sounds illegal to me - blowing fresh air into the exhaust? I have no idea though.
I was once told that the units were un-fused and can cause fires if they fail?! Hopefully someone who knows what they are talking about will give you a better reply!
Crikey, every day is a learning day.
I've owned a series of 6 cylinder BMWs over the past 14 years and had never heard of this part.
Anyhow
I've owned a series of 6 cylinder BMWs over the past 14 years and had never heard of this part.
Anyhow
some American website said:
The secondary air pump, located near the firewall on the passenger side of the engine compartment, draws air from the engine compartment and injects it into the exhaust manifolds to provide extra oxygen to the catalytic converter and reduce cold start emissions. A non-return valve mounted on the exhaust manifolds normally prevents exhaust gases from flowing back into the pump. When the non-return valve fails, moisture in the exhaust gases accumulates in the pump, causing it to eventually fail.
This pump normally sounds like a vacuum cleaner under the hood, and it only operates for the first couple of minutes after you start the car. It will not leave you stranded if it should fail. You can replace the parts at your leisure, unless you have an emissions inspection coming up.
Before replacing the pump and valve, you must first verify that (1) the pump is getting power, (2) the vacuum hose leading to the non-return valve is intact and free of blockages, holes, and cracks, and (3) the vacuum switch under the intake manifold is working properly. Power problems, a leaky hose, or a faulty switch can also set off the Check Engine light, which means you may not need a new pump and valve after all.
This pump normally sounds like a vacuum cleaner under the hood, and it only operates for the first couple of minutes after you start the car. It will not leave you stranded if it should fail. You can replace the parts at your leisure, unless you have an emissions inspection coming up.
Before replacing the pump and valve, you must first verify that (1) the pump is getting power, (2) the vacuum hose leading to the non-return valve is intact and free of blockages, holes, and cracks, and (3) the vacuum switch under the intake manifold is working properly. Power problems, a leaky hose, or a faulty switch can also set off the Check Engine light, which means you may not need a new pump and valve after all.
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