Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: dave abra on 16 May 2010, 13:06:10
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Hello
You guys have been really helpful over the years but i wonder if you can give some suggestions this time
My 2.5 V6 98 omega hesitates when given some throttle. Doesn't do it some much when the car is cold. It does do it mostly when leaving a roundabout, so i have some speed but getting more speed is an issue. rev counter goes up and down when accelerating.
I have already changed the following.
ICV is new.
MAF is new.
EGR is replaced but not brand new. This improved things but not a cure.
Any thoughts on what might still be the issue would be great.
Thanks
David
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Have you checked for any fault codes?
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yeah.
just did paper clip test and got number 31 No rpm signal
What does that suggest?
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Code 31 will show on the V6 when the ignition is on BUT the engine isnt started. Once u fire up the car the code will disappear :y
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oh yeah. i remember reading that somewhere.
no other codes then at the moment.
Any ideas what it might be
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Havn't got the faintest idea :-/ but as mines running rough i look forward to one of the experts to come back to u :y
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Pul a plug lead from each bank and check for oil in the wells.
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Thats already been checked. The plugs are good and it runns as sweet as a whistle. apart from the hesitating
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Plug leads ?
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I believe they are good. Garage said they are ok. will have a look myself.
Any other ideas? while i am there
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Hello
I still am having issues with my V6 hesitating. Have read a few other posts on vauxhall forums, not specific to omega's, that coil packs or a dodgy injector could be the source of my problems.
Do omega's suffer the same issues as 1.6 astra's? in this area?
Please help. it is driving me bonkers.
Cheers
David
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if it was coil pack i would have thought it would show up a misfire code and been more noticeable :-/
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Would disconnecting the EGR have any effect. I read somewhere that if i do that the ECU would need an update from a tech 2.
Is that right.
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air leaks? you have no fault codes, better when cold.
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A little better when cold. not always though.
have checked air pipes. well the ones i can see anyway. Are there any well hidden i should know about.
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I bet a pound to a penny it'll be your dis pack :y
Mine was 'fatigued', no fault codes shown, changed plugs, leads, egr (buggered it up trying to force it open to clean it - dohhh!!), tested HG, checked all pipes, would have checked me hair in the mirror but i'm bald!
Last thing changed was the dis pack & hey presto - back to normal with no misfiring, hesitation or spluttering!!! :y :y :y
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Subscribed! Keeping a close eye on this I have a virtually identical problem.
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i now have code 91 and code 33 so am going to blanking egr.
might try dis pack after that.
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I just had similar problem, and it was faulty dis pack.
(although, first I had also one faulty ht lead)
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When were the plugs last changed?
They do last a long time but when the electrodes erode the spark gap gets too big.
I noticed the misfire most when accelerating but also at idle when the plugs on my last V6 were well past their best.
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The crank sensor on my 4 pot gave me very similar symptoms without initially throwing up a code or putting the EML on. It did both a little later on when the car began to cut out around 3500-4000rpm! Worth bearing in mind ? :y
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leads and plugs are not old and garage, not vx, has said they are fine.
I am going to try and blank the egr. i think it might be sticking. since i have the codes it is worse. was fine at idle before. now it is lumpy and vibrates up up the pedals and when going 50ish, vibrates through the seats which makes for an unpleasant ride.
If blanking the egr doesn't do it i will try the dis pack. Have heard they are tricky to change so will not be looking forward to that.
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leads and plugs are not old and garage, not vx, has said they are fine.
I am going to try and blank the egr. i think it might be sticking. since i have the codes it is worse. was fine at idle before. now it is lumpy and vibrates up up the pedals and when going 50ish, vibrates through the seats which makes for an unpleasant ride.
If blanking the egr doesn't do it i will try the dis pack. Have heard they are tricky to change so will not be looking forward to that.
How do they know?
The plugs are a pain to get to so I doubt very much whether the garage has had them out to check. Genuine VX ones cost about £3 each. If you don't know how old they then they are probably knackered.
I changed the plugs on my 2.6 a week ago as part of a 120,000 mile service. The old one on the right appears to have twice the gap of a new one.
(http://homepages.nildram.co.uk/~aholter/PICT4771A.JPG)
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I asked the local garage to look when they were fixing the air con and checking for a water leak. I go there all the time so i know they actually looked. they also look after my company van so i trust them. The plugs were new about 15000 miles ago.
This problem has been rumbling on since i have had the car which is about 40000 miles.
has never run really smooth. getting sick of to be honest.
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leads and plugs are not old and garage, not vx, has said they are fine.
I am going to try and blank the egr. i think it might be sticking. since i have the codes it is worse. was fine at idle before. now it is lumpy and vibrates up up the pedals and when going 50ish, vibrates through the seats which makes for an unpleasant ride.
If blanking the egr doesn't do it i will try the dis pack. Have heard they are tricky to change so will not be looking forward to that.
got same thing - worse about 74 mph just changed plugs, leads and cam cover gaskets and it cures it... for 3 miles and then comes back again Angry
also found air leak on breather/plenum/trottle body connection but even after sorting that it still vibrates like hell with weird tapet from engine like struggling to go up revs Sad dis pack then ?
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Hello
So the car is running really rough sounding. Idle is ok but it vibrates through the car. This co-insides with the codes 33 and 91 appearing. Having said that it flashes 9 1 and then 2. for three times. What does that mean. i thought the paper clip test only brought back a 2 digit. not three.
So blanked of EGR valve. is very slightly better but the codes are still there and idle still vibrates around the car. The engine sounds like normal, as smooth as it normally sounds. the unsual bit is the exhaust. Sounds like air is being forced out. It doesn't smell of fumes or petrol but fuel consumption has dropped to 20
Does anyone know what code 91 is all about. what is o2 sensor 2?
The next thing would be to change the dis pack.
Please please help as i am going spare. i have a really nice car which i just can't running anywhere near well.
Thanks
David
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91 O2 Sensor 2 Circuit Voltage High
according to this http://www.omegaowners.com/forum/YaBB.pl?num=1160152415
So I googled o2 sensor 2 circuit voltage high and got (amongst others) this. http://en.wikipedia.org/wiki/Oxygen_sensor
I'm no engineer but this does seem to point towards low mileage figures and lesser performance.
"Failure of an unheated sensor is usually caused by the buildup of soot on the ceramic element, which lengthens its response time and may cause total loss of ability to sense oxygen. For heated sensors, normal deposits are burned off during operation and failure occurs due to catalyst depletion, similar to the reason a battery stops producing current. The probe then tends to report lean mixture, the ECU enriches the mixture, the exhaust gets rich with carbon monoxide and hydrocarbons, and the mileage worsens"
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Hello
You guys have been really helpful over the years but i wonder if you can give some suggestions this time
My 2.5 V6 98 omega hesitates when given some throttle. Doesn't do it some much when the car is cold. It does do it mostly when leaving a roundabout, so i have some speed but getting more speed is an issue. rev counter goes up and down when accelerating.
I have already changed the following.
ICV is new.
MAF is new.
EGR is replaced but not brand new. This improved things but not a cure.
Any thoughts on what might still be the issue would be great.
Thanks
David
For hesitate to shift gearbox oil check has been suggested in other posts in case it triggers anything.
Hesitate to rev up (not your situation) has been related to a clogged fuel filter/pump issues.
If you have the old MAF and only change that element, did you see an improvement and what type unless you had codes that got cleared as a clear MAF issue?
Cheers in case it triggers anything for a solution.