Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Malcolm_D on 20 June 2010, 23:56:36
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Before I changed the rocker seal on the left bank the car occasionally idled a bit up and down and stalled at lights quite often, when I put it back together the revs on idle went from 1200 to 2000 very rythmically! OK from cold but after 4/5 mins off it went. I couldn't sort it so off to the garage it goes, it has been there 5 weeks and they are stumped! It's not the ICV, the crank sensor, blocked breathers, leaking breathers or MAF sensor. So what the hell is it? Anyone got any bright ideas? It has been on a Tech 2 - this reported a faulty crank sensor but they have tried that with no joy. Please help, I am desperate! Is my next step to pay the garage bill and scrap the beast?
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Not the icv? Explane?
And welcome by the way :y
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ive had a similer fault and it turn'd out to be the ecu temp switch had a fault so just changed it and worked fine after that cuts out the ecu thinking its been stud to long so was told by vx, but dont know about that, any way itstoped when it was changed.
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ICV removed cleaned and lubricated with v. light oil, seal to plenum checked thoroughly. Garage checked it too and gave it the OK, tested by removing it with car running - problem still there. Should they have done anything else?
Thanks for the welcome and the suggestions.
When I last visited the garage to chat to Dave (the mechanic who is scratching his head - great bloke but severely puzzled) he mentioned that he was going to look at two temperature sensors next.
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samesame - sounds worth a look where will I find the ecu temp switch?
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ICV removed cleaned and lubricated with v. light oil, seal to plenum checked thoroughly. Garage checked it too and gave it the OK, tested by removing it with car running - problem still there. Should they have done anything else?
Thanks for the welcome and the suggestions.
When I last visited the garage to chat to Dave (the mechanic who is scratching his head - great bloke but severely puzzled) he mentioned that he was going to look at two temperature sensors next.
Ideally swap it for a known good one, where are you? Maybe someone can lend you there's.
Are there any chips in the valve edge making the valve stick for instance? It sounds iffy, mine took several cleans with carb cleaner before mine behaved on my old car.
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its in with the ecu attached to the ecu, some are on out side and some are in the ecu.
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I am in York. To be honest the change between revs of 1200 and 2000 to me is too regular to be something mechanical like the valve edge in the ICV but I am willing to try anything. I will see if I can get hold of one.
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samesame - thanks, I will tell Dave the mechanic so that he can have a look at it.
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its in with the ecu attached to the ecu, some are on out side and some are in the ecu.
another thing when it got hot outside 20+c it got worse, but in winter worked fine. :y
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its in with the ecu attached to the ecu, some are on out side and some are in the ecu.
another thing when it got hot outside 20+c it got worse, but in winter worked fine. :y
Rusty are you comparing this v6 with a four pot?
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I am in York. To be honest the change between revs of 1200 and 2000 to me is too regular to be something mechanical like the valve edge in the ICV but I am willing to try anything. I will see if I can get hold of one.
It's one of many places to look further IMO. Also retrace steps with the intake, check all the seals to plenum and manifold are seated correctly. Start with the easy stuff and go deeper.
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shuts down ecu turns off engine.no fault codes
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Any experienced members near York could take a look at this one?
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had similar problem on an astra ,it was the main earth wire at back of block for some reason it was giving strange signals to ecu when swapped all problems ceased best fiver i ever spent!
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Got a call from the garage with a tentative message of progress made! Dave (magic mechanic) told me that he had made some changes to the base settings? This appears to have sorted the problem though he has asked me to run it for a couple of weeks just to check, I think he would have preferred to have found a more definite cause of the problems. Idle revs are a touch high, 1000 when not in drive, drops to 700 in drive. Am keeping my fingers crossed! Thanks for all of your help & suggestions.
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had similar problem on an astra ,it was the main earth wire at back of block for some reason it was giving strange signals to ecu when swapped all problems ceased best fiver i ever spent!
Good result, sometimes we look too deep first.... :D
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Got a call from the garage with a tentative message of progress made! Dave (magic mechanic) told me that he had made some changes to the base settings? This appears to have sorted the problem though he has asked me to run it for a couple of weeks just to check, I think he would have preferred to have found a more definite cause of the problems. Idle revs are a touch high, 1000 when not in drive, drops to 700 in drive. Am keeping my fingers crossed! Thanks for all of your help & suggestions.
Tbh mate I'd get one of the guys on here to have a look at it, suspect he's nobbled the butterflies in the throttle body to get it go tick over as icv is not doing it's job or similar reason. But whatever, it's not right. 1000 rpm is too high.
Changes to base settings = bodge. Tech 2 is the only way go adjust tick over as I understand it.
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If I am honest I had similar thoughts - I just want it sorted! Anyone in the York area who feels competent enough to have a look for me or at least discuss what my next step should be?
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If I am honest I had similar thoughts - I just want it sorted! Anyone in the York area who feels competent enough to have a look for me or at least discuss what my next step should be?
Mark dtm is in nottingham, bit far, or maybe daz, Darth loo knee, will travel up? or Elite Pete?
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I had a similar problem with my V6 - it was fine on gas but on petrol when warm would idle from 1200 upto 2000 rpm then drop abruptly back down to 1200 again increasing back up again, had the plenum off and cleaned everything in sight with lots of carb clean and compressed air, put it back - exactly the same, broke paint seal on idle screw, never been touched before, backed it out (a lot) - problem solved.
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So where is this idle screw and can you alter the idle mechanically? Chrisgixer reckons you can only alter tickover with tech2 and he appears to know what he is on about.
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I read your reposrt of this mechanic and I am worried.
Its classic air leak symptoms.....and the simple basic test is to wack a vac gauge on it to see whats occuring.
Temp sensors can be checked out using live data via tech2 or any other good scan tool.
Base settings do NOT ever need buggering with.......doing so is only a method to bodge around or mask the real cause :y
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So where is this idle screw and can you alter the idle mechanically? Chrisgixer reckons you can only alter tickover with tech2 and he appears to know what he is on about.
They are not idle screws, they are throttle stop screws. The idle control valve (ICV) controls the idle air. The throttle stop screw stops the throttle valves from chewing away at the inside of the throttle body when they close.
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OK so back to the garage and I get them to put the settings back to what they were. What do I need to do a vac test, how do I do it or does anyone know where, near York, I can get it done along with a tech2 analysis?
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I too am reading this as an air leak. I would be inclined to take the hit and try and have a day out somewhere to a member who knows what they are doing, rather than using a garage that are struggling to understand the engine.
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I agree but I need some kind soul to make the offer - ANY OFFERS? Happy to travel a distance but I might have to leave it for 6/7 weeks as I am really pushed for time at the moment. After that I am totally flexible for 3 weeks as I am on holiday with nowhere to go. Looks like it is back to the bike for me!
Reluctant to suggest but would the Vx main dealer mechanics have a better chance than my independent guy, they should know these engines inside out.
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Generally, avoid the dealers, and avoid independent garages who do not understand that v6 engine.
If no offers of help appear, try Darth Loo-knee who does mobile servicing.
Hope that helps
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It does, thanks.