Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Chris G on 03 April 2010, 16:45:05
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I'm having big problems starting from cold, and I think it might be related to a couple of other issues which the good old Haynes manual doesn't cover at all, so over to the forum!
I have a 1999 2.5V6 Petrol CDX Auto with Aircon. For the last few weeks I've noticed a loud, high-pitched fan-like noise coming from somewhere under the nearside front wing, behind the headlight, just after starting from totally cold. The noise runs for about a minute after starting then shuts off. In the minute it's on I haven't been able to locate what's causing it but as it's when the engine's stone cold it shouldn't be either of the cooling fans.
Just recently cold starts have been a REAL pain, having to crank for ages and usually flooding the engine. This morning it just wouldn't start. Checking the fuses under the bonnet, one of the 30A fuses was blown. It's at the rear of the box, on the left as you look at it from the front, and is labelled as "28a(Green)" under the relevant posting on the FAQ forum. I have no idea what this fuse does, but when I replaced it the car started (after cranking for about 5-10s with a flooded engine) and this time the "fan" noise was distinctly dodgy, like there was something caught in it. After a minute it shut down and the car was perfectly happy (and will be till tomorrow morning as it only has a problem when totally cold).
Looking through the circuit diagrams in the Haynes manual I found there's a 30A fuse in the "Coolant Heater" circuit (whatever that is!) but there's no other mention of it.
Question is: Does anybody know what the "fan" noise is, what the mysterious fuse does, and if there's something jammed somewhere how to free it?
Thanks
Chris
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30amp is for the Motronic control unit. Noise is the secondary air injection pump (SAI). Unplug it, not needed and it`s a PITA
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Where are you Chris?
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I'm in the Forest of Dean, Gloucester side. It may be a dumb question, but what's the secondary air injection pump actually do (apart from inject air!), and what might make the motronic fuse blow? And would either explain my cold start problem?
Cheers
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SAI is for emissions, helps reduce them when cold. It was ditched on the later DBW engines, unplug it :y
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Consider it unplugged, once I get the wheel arch liner out! ;) Could a jammed/faulty SAI cause the motronic fuse to blow?
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OK, no need to remove the liner, pulling fuse F49 (29b in the diagram) appears to do the trick without disabling anything else. (Haynes manual IS good for something!) Will see if that affects the cold start tomorrow morning...