Whistle on start-up

Hi folks, I have a 2litre Omega which sounds like an aircraft engine
for about the first minute after starting in the mornings. Indeed, if
the car's left for more than about 4 hours at a time it does it. The
noise is coming from under the bonnet - but not from the engine - and
because of the way it echoes in the engine bay I haven't been able to
track it down.

The noise is really piercing and pedestrians stop and look as I go by
so it must be pretty loud outside. Does anyone have any ideas what it
might be?

Regards
Steve G

 

If the noise stops suddenly, the most likely cause would be associated with
the secondary air pump, which only runs for a couple of minutes from cold.
The injection of air is supposed to aid the oxygen sensor warm up quickly.
There will be an air pipe which goes into the exhaust manifold. There is a
possibility that a chunk of carbon is acting as a reed, causing the noise,
either that, or the pump is damaged.

 

The noise stops like somethings been switched off, so "suddenly" would
be a good description. More things to check this weekend :-(

s'funny but I spend more time sorting little problems out on the Omega
tha I do on my 1970 Series 2a Land Rover which, with 420,000 miles on
the clock, could be forgiven for being a bit troublesome

Regards
Steve G

 

420k on a Landrover sir? Just nicely run in !!

 

You wouldn't say that if you were chewing on the blue smoke it trails
along behind everywhere we go

LOL
Steve G