Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Shimmy on 16 September 2010, 01:08:18
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Hi there everyone.
I'm the 'new' owner of a 3.2 omega as of 3 weeks now, and until very recently has served me very well. The car came with a good history (recent service/timing belt kit change/exhaust), and upon inspection was very clean. It in fact still runs perfectly well at the moment.
However a few days ago when I lined up to overtake a lorry going up an incline on an NSL road, I pressed the sport button and accelerated sharply to overtake. As soon as this happened the EML came on and I was limited to 2k revs and it sounded like a couple of cylinders were misfiring. When I could, I pulled over and switched off the engine and looked under the bonnet. Everything looked perfectly fine, so I started it up and it ran fine once again with no EML. But the dash light with the spanner through the car now became illuminated. It has remained in this state for the last few days, running seemingly perfectly normal whilst putting on a few hundred miles including two 5 hour round trips on very mixed roads.
I've since reacquainted myself with the service history of the past owner, and found that the timing belt kit change and service had been done at the end of last year at an independent. Around the same time Kwik Fit (:/) had also replaced the exhaust. And more recently the last owner had taken the car to the Vauxhall main dealer to get rid of this warning light (spanner through the car) to the tune of £450, replacing the lambda sensor and another sensor which I have the part number of.
Having read through some of the guides and had a search on this site I managed to utilise the pedal trick to get some fault codes:
0130 & 0150 - Both lambda sensors
0170 & 0173 - Both banks, fuel trim malfunction. MAF?
0300 - misfire detected
0304 & 0306 - cylinder 4 & 6 misfire detected
1110 - Intake manifold valve
Seems like the vauxhall monkeys didn't do a good job of finding the fault, as both lambda sensors give errors now. And as both banks of the fuel trim are malfunctioning it leads me to believe something that runs before these components is at fault. Your ideas?
The engine actually sounds and seems to run fine with no dip in performance since that attempted overtake in sport mode, although I haven't tried it in sport mode since! So will the fault code be produced because of that isolated incident, or is still misfiring now?
The only thing I can think of is that the MAF perhaps needs replacing? Also the fairly recent change of the the exhaust back box could lead to the lambda sensor trouble, does that mean a new back box is needed? Or can the MAF be at fault for that too?
As I say the car seems to run perfectly fine since that isolated incident and had covered over 500 miles in about 5 days without complaint. I also started to use premium unleaded as my dad had a similar issue with his 7 series, his engine would go into limp home mode sometimes under sharp acceleration until he changed to premium unleaded. This is why I have been running it since.
If anyone has any ideas what could be at fault I'd be very happy!
I personally think it's the MAF at the moment which is causing these fault codes, but if there are other things I should be looking at please let me know. :)
Kind Regards.
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You'll get some better answers during daylight hours but as a start I'd advise you to quickly check the plug wells for oil :y this could cause the missfire codes which could, in turn, cause mixture codes :y
It's probably worth updating your profile with a location as you may need to visit someone with the facility to clear the fault codes to see if they come back.
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Air leak in vac system affecting front multi ram and allowing air into the system upsetting fuel balance....maybe? Not sure that lambdas would cry foul in that case though...? :-/
This is something of a guess, so see what others say, but it's something to check while others more knowledgable come along.
My LPG vac referance pipe tpiece by servo pipe vac pipes got dislodged a while back, caused air leak, lumpy running and 0300 0301/3/5 and fuel trim. But this happened at about 20mph, might upset lambda's further down the line at higher rpm...?
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First things first, as already mentioned, check the passengers side plug wells for oil or water, splits in the boots or on the CPP unit itself.
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How much of the exhaust system did Kwikfit replace? Has it had new pre-cats on it?
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Sounds like who ever has been there before has not done to hot a job.
0130 O2 sensor circuit malfunction (Bank 1 Sensor 1)
0150 O2 sensor circuit malfunction (Bank 2 Sensor 1)
0170 Fuel trim malfunction (Bank 1)
0173 Fuel trim malfunction (Bank 2)
0300 Random/multiple cylinder misfire detected
0304 Cylinder 4 Misfire Detected
0306 Cylinder 6 Misfire Detected
1110 Intake Manifold Valve 1 Open
1110 sudgests that the plenum has been off and the rear multiram electrical connector has not been re-fitted.
Do check the plug holes for oil but, personal experience sudgests that given the fuel trim malfunction, you have a MAF fault (sadly on the 2.6/3.2's these are not nearly as reliable as the older 2.5/3.0 ones).
Viewing of live data would confirm this as the issue
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Thanks for the replies chaps.
The plug wells are fine. The car as I say runs fine. So I'm guessing the fault codes don't disappear by themselves and need to be wiped? Can I do this by disconnecting the battery for an hour or are there any adverse affects?
If the light persists afterwards I'm guessing it wouldn't fail an MOT; which I have next month.
I'm tempted to change the MAF though, how much for a replacement and are they easy to change myself? Seemed easy enough on an MX5.
Cheers.
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^
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You can replace the MAF in about 10 seconds flat. It's located on the large air intake pipe before the throttle bodies.
I'd suggest it isn't the problem though.
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I believe you can test a MAF by driving the car with it disconnected. If no change with the problem then the MAF is ok.
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You can replace the MAF in about 10 seconds flat. It's located on the large air intake pipe before the throttle bodies.
I'd suggest it isn't the problem though.
Totaly disagree with you on that one sadly.
Its classic MAF faults.
We have issues on BOTH banks related to mixture control.....as the mixture is pushed out miss fires will occur on the weakest cylinders.
If it was oil or a coi pack I would expect mixture issues on a single bank related only to that coil pack.
The only key item that can cause such symptoms is the MAF but, as said, I would be chcking live data for confirmation.
MAF's are available of varying quality.
The Vx part code is 93171760 which is a Bosch item part number 0281002184
http://desc.shop.ebay.co.uk/i.html?_nkw=0281002184&_sacat=0&_dmpt=UK_CarsParts_Vehicles_CarParts_SM&_odkw=0281002184&_osacat=0&_trksid=p3286.c0.m270.l1313&LH_TitleDesc=1&_rdc=1
Do beware of the cheap ones, they may be short lived or you might be lucky
You will also note they are used by quite a few other manufacturers
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Thanks for the replies chaps.
The plug wells are fine. The car as I say runs fine. So I'm guessing the fault codes don't disappear by themselves and need to be wiped? Can I do this by disconnecting the battery for an hour or are there any adverse affects?
If the light persists afterwards I'm guessing it wouldn't fail an MOT; which I have next month.
I'm tempted to change the MAF though, how much for a replacement and are they easy to change myself? Seemed easy enough on an MX5.
Cheers.
For info, as long as the light is on there is a fault PRESENT, if no faults are currently present, the codes will be stored but the light off.
Given the faults you have I would say an emmisions pass may be a challenge (it would be interesting to see) as you will not be running closd loop as the ECU wont trust the lambda readings
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An update to this thread.
The intake manifold valve has been replaced and fault codes wiped.
After a 10/15 mile drive the EML came back on again. This time the pedal trick only emitted 2 fault codes:
0150
0173
Which means they both indicate the 2nd bank with regards to the O2 sensor and fuel trim.
Again, the car drives perfectly fine. But I don't fancy driving around with the EML on and also have my MOT in the next couple weeks.
Any ideas as to what is playing up?
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Slight bump, any ideas chaps? Got my mot in 10 days or so.
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I would be surprised if the intake manifold valve had much influence on the other faults, TBH. It would make it a little flat but not much more of any consequence.
I'd still suspect a MAF problem. Perhaps only one bank has drifted out far enough to raise a code so far?
I'd say get some live data from it and see what the MAF is reading and what the fuel trims and lambdas are doing.
Kevin