Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: charlieboy1 on 29 August 2014, 07:52:32

Title: my cat revs just before it stops
Post by: charlieboy1 on 29 August 2014, 07:52:32
I wonder if anyone can help I have an omega B 1995 2.5 auto saloon. when I brake just before the car stops it revs like it wants to take off.

I have change the idle control valve and also the egr but this still happens.

Can anyone help?
Title: Re: my cat revs just before it stops
Post by: minifreek on 29 August 2014, 11:01:02
Did you change the ICV for a new item or a 2nd hand 'cleaned' item...?

It does however sound like the ICV is playing up, but it could be the throttle body needs a clean along with the breathers too...

It also sounds to me like the cam sensor is starting to show signs of wear/use, not expensive to replace. But when they do 'go' they usually put the engine into limp mode...
Title: Re: my cat revs just before it stops
Post by: Matchless on 29 August 2014, 13:25:49
Try lifting off the throttle and immediately put the 'box into neutral......does the engine rev now? If yes then look at the throttle body, IACV and look for air leaks.
But if the engine returns cleanly to idle when you do this and it only revs when you brake then the problem could be to do with your brake servo or the servo vacuum line.
Title: Re: my cat revs just before it stops
Post by: powerslinky on 29 August 2014, 19:08:32
Did you change the ICV for a new item or a 2nd hand 'cleaned' item...?

It does however sound like the ICV is playing up, but it could be the throttle body needs a clean along with the breathers too...

It also sounds to me like the cam sensor is starting to show signs of wear/use, not expensive to replace. But when they do 'go' they usually put the engine into limp mode...

IMO .  . cam sensor failure on a V6 is  almost unheard of

but it is  common on the 4 pots .         But OP has a 2.5
Title: Re: my cat revs just before it stops
Post by: dbug on 29 August 2014, 21:43:25
Did you change the ICV for a new item or a 2nd hand 'cleaned' item...?

It does however sound like the ICV is playing up, but it could be the throttle body needs a clean along with the breathers too...

It also sounds to me like the cam sensor is starting to show signs of wear/use, not expensive to replace. But when they do 'go' they usually put the engine into limp mode...

IMO .  . cam sensor failure on a V6 is  almost unheard of

but it is  common on the 4 pots .         But OP has a 2.5

Agreed Al, but . . .  when we first got our 2.6V6 it kept stalling, but restarted straight away - under warranty crank sensor was replaced by Vx main dealer, no change.  Code was for cam sensor (Vx dealer also said they were unlikely to go), so they fitted new cam sensor - problem cured ;)
Title: Re: my cat revs just before it stops
Post by: powerslinky on 30 August 2014, 06:40:51
Did you change the ICV for a new item or a 2nd hand 'cleaned' item...?

It does however sound like the ICV is playing up, but it could be the throttle body needs a clean along with the breathers too...

It also sounds to me like the cam sensor is starting to show signs of wear/use, not expensive to replace. But when they do 'go' they usually put the engine into limp mode...

IMO .  . cam sensor failure on a V6 is  almost unheard of

but it is  common on the 4 pots .         But OP has a 2.5

Agreed Al, but . . .  when we first got our 2.6V6 it kept stalling, but restarted straight away - under warranty crank sensor was replaced by Vx main dealer, no change.  Code was for cam sensor (Vx dealer also said they were unlikely to go), so they fitted new cam sensor - problem cured ;)

As said Colin  . . . Almost unheard of  . . . .     trust it to be you to be the one who had to have it replaced LOL ! ;D ;D ;D
Title: Re: my cat revs just before it stops
Post by: 05omegav6 on 30 August 2014, 10:12:44
Had to change one on a loaner 3.2 from Josh... wasn't running right and threw up a cam sensor code, swapped with second hand and it was fine thereafter  :y

Unlike the V6 crank sensor, which hardly ever throws the correct code, the cam sensor code means the cam sensor is toast :y