Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: oslo on 11 March 2012, 11:45:24

Title: Engine racing
Post by: oslo on 11 March 2012, 11:45:24
Hi, got an engine problem with my manual transmission Omega, symptoms are similar to when first starting the car on a cold morning except this is occurring when engine is hot (around 97.5 on my temp guage) after for instance coming off motorway.  When changing into neutral, engine revs don't drop ie engine is racing, then engine revs very slowly drops.  These symptoms persist while engine is hot.  This obviously means I have jerky gear changes (different biting point) and fuel consumption is affected

Have checked throttle cable and doesn't appear to be fouled.  Being in my fifties, in olden days I would have diagnosed carburetor needed cleaning but I'm not so familiar with fuel-injection.  Anyone have any ideas ??  Apart from this, engine performance good, no dash warning lights and fluid levels checked regularly
Title: Re: Engine racing
Post by: RobG on 11 March 2012, 12:12:31
Hi, got an engine problem with my manual transmission Omega, symptoms are similar to when first starting the car on a cold morning except this is occurring when engine is hot (around 97.5 on my temp guage) after for instance coming off motorway.  When changing into neutral, engine revs don't drop ie engine is racing, then engine revs very slowly drops.  These symptoms persist while engine is hot.  This obviously means I have jerky gear changes (different biting point) and fuel consumption is affected

Have checked throttle cable and doesn't appear to be fouled.  Being in my fifties, in olden days I would have diagnosed carburetor needed cleaning but I'm not so familiar with fuel-injection.  Anyone have any ideas ??  Apart from this, engine performance good, no dash warning lights and fluid levels checked regularly
Sticking butterflys on throttle bodies :-\
Title: Re: Engine racing
Post by: Lazydocker on 11 March 2012, 12:12:47
Idle Control Valve would be my first point of call.... Give it a really good clean :y
Title: Re: Engine racing
Post by: dbug on 11 March 2012, 14:28:00
As he said ^^^^ clean ICV
Title: Re: Engine racing
Post by: oslo on 11 March 2012, 18:42:22
Cheers for replies - are butterflies and ICV connected or similar   ???  Don't have so much experience on modern engines  :y
Title: Re: Engine racing
Post by: doz on 11 March 2012, 18:44:45
Have a good look around for any split hoses. It maybe suffering from a air leak
Title: Re: Engine racing
Post by: oslo on 11 March 2012, 19:11:11
Have a good look around for any split hoses. It maybe suffering from a air leak

Another one added to the post count eh ?? ;D
Title: Re: Engine racing
Post by: oslo on 11 March 2012, 19:17:25
Have a good look around for any split hoses. It maybe suffering from a air leak

I see this has come up before actually so will check vac hoses after giving ICV a good old clean  :y
Title: Re: Engine racing
Post by: Andy H on 11 March 2012, 19:32:14
Hi, got an engine problem with my manual transmission Omega, symptoms are similar to when first starting the car on a cold morning except this is occurring when engine is hot (around 97.5 on my temp guage) after for instance coming off motorway.  When changing into neutral, engine revs don't drop ie engine is racing, then engine revs very slowly drops.  These symptoms persist while engine is hot.  This obviously means I have jerky gear changes (different biting point) and fuel consumption is affected

Have checked throttle cable and doesn't appear to be fouled.  Being in my fifties, in olden days I would have diagnosed carburetor needed cleaning but I'm not so familiar with fuel-injection.  Anyone have any ideas ??  Apart from this, engine performance good, no dash warning lights and fluid levels checked regularly
I think your diagnosis is still valid (except that the component parts have been repackaged, renamed and are now dependent on electrickery for every action).

The engines used in the Omega are prone to blocked crankcase breathers. Usual symptoms are leaking cam cover gaskets but another symptom can be gummed up throttle butterflies and idle air control valves.

If the ICV is gummed up then clean the breathers too (correction, if you don't know when the breathers were cleaned then clean them regardless).

Have a read through the excellent maintenance guides Maintenance Guide Index (http://www.omegaowners.com/forum/index.php?topic=90633.0)

in particular this one V6 Cleaning the Crankcase Breathers (http://www.omegaowners.com/forum/index.php?topic=90653.0)
Title: Re: Engine racing
Post by: Elite_L0ver on 12 March 2012, 17:40:01
http://www.omegaowners.com/forum/index.php?topic=90653.0

As he said do this it will help clean butterfly's and breather system