hello just joined and i think this site is fantastic i am getting a high pitched noise when i start the engine and it takes about 2 to 5 mins before it cuts out it doesnt sound normal has anyone had the same problem or might know what the problem might be thanx

v6 cdx wrote on 10. Jan 2007 at 23:00:


As iggy21uk said, what year, and which engine – presumably a V6 from your username…?

The Omegas have a secondary air pump which pumps air into the intake manifold when the engine is cold in order to reduce emissions. It is possible that this what you hear, though the typical notice it makes would be more like hammering and not a high pitch one – best way to check it is to either disconnect it or remove the relay or fuse controlling it. If the noise goes away then this is your problem.

If it is the secondary air pump, you will need to establish if it actually faulty – some noise is normal, but excessive noise means there is a problem with it. If the pump is proven to be faulty, it can generally not be repaired, you will need to either replace it (with a new unit or one from the scrap yard) or just disconnect it and live without it – it is not that important, and if you disconnect the pump the car will not fail the MOT because MOT testing is carried-out with the engine warmed-up to working temperature and by that time the pump would not have been working anyway.

Agreed with you on the secondary air pump again but just to confirm

Where would you say the noise is coming from as to rule out any other part of the engine.

If the noise is coming from the passenger side inner wing then this will most definately be the secondary air pump. The pump itself is more visible from looking underneath the car just above and behind the horns.

Secondary air injection pump lives under the passenger side front wing, ahead of the wheel. Reach up past the horns and you should find a connector for it.

To correct an earlier post....The pump forces fresh air into the exhaust manifold. The secondary air system is active on start-up until the lambda (oxygen) sensors in the exhaust get hot enough to start working, during this phase the ecu has to run the engine very rich to guarantee idle on cold start so there will be unburnt fuel in the exhaust, the air injection allows this fuel to re-burn in the manifold and down pipe rather than letting it escape into the atmosphere. This re-burn has the added benefit of heating the catalysts more quickly so overall exhaust emissions are reduced.

It might just be a holed air injection pipe from the pump. The vacuum valve is fastened to the fan bracket just inside the bonnet and slightly to the right of center. It's the pipe coming out of the right hand side of the valve that usually fails and it usually fails because the non return valve it goes to has failed.

Sounds like the secondary air pump to me. Completely harmless.

If it annoys you unlpug it or take the fuse out - see recent post on fuse location:

http://www.omegaowners.com/forum/YaBB.pl?num=1168529679