Help!
My local private hire chappie runs a 2.0 (?) Omega, and has spent much money on (not) sorting out a rough idle problem.
It has been to a local Vaux. indie, plus had diagnostics on it, as well as a new air valve. No joy. It ticks over like a Wright Cyclone radial engine (as in DC-3) on startup.
He's despairing, and it's eating into his meagre profits.
Does anyone know of a common fault on these machines?
Cheers
rg
'97 2.5 Citroen XM Estate
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Is it rough or just slow?
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Simplicate and add lightness!!
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Sounds "rough" to me (but drink had been taken - hence the need for a taxi...).
Perfect otherwise, pulls fine, picks up OK.
It's just really frustrating the chap. And costing.
rg
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Suggest it has a vacuum leak, possibly the inlet manifold gasket.
Andrew
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Simplicate and add lightness!!
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Assuming the two garages have done the obviuos, as Andrew suggested, I would be doing an emissions test to see if she is firing/fueling properly, a leak test to try and identify a possible head gasket problem between two cylinders or a burnt valve. Is the roughness associated to one cylinder ( a valve ) two ( the gasket ) or all of them ( fueling or air leaks ) as this would point to different problems. Regards Peter
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Like Andrew, I would suggest an air leak as a highly likely cause. I used to check for an air intake leak by slowly moving a (unlit) butane soldering torch around the joints. Listen very carefuly to the note of the engine. if there is an air intake leak then the note will change when the butane is taken in instead of just air. Alternatively use a stethoscope (£4 from ELC) and move the end of the tube around the joints - you should be able to hear an air leak. Alternatively try spraying WD40 on the joints - it'll get sucked into any leaky areas very quickly.
My own car and my brothers, get very similar symptoms when the throttle body gets really dirty. this happens regularly on mine (petrol turbo), but less often on my bros. take off the air intake pipe at its union with the throttle body and look inside. If it's dirty clean it with spray carb cleaner and an old toothbrush. DO NOT overtighten when you replace the pipe.
Have you checked the HT leads? Put the car in a garage or other totally dark place and lift the bonnet. Get an assistant to turn out the lights (or else use a torch - don't grope around the engine bay in the dark with it running) and look for any sparks escaping from the leads. Also look to see if you can see a single spark inside any lead at one place - suspect a broken inner conductor if you can. Also check the leads for physical damage and for cracks or splits.
Check all breather pipes, especially small bore ones, for any blockages or splits particularly at the ends. Clean out with carb cleaner.
If you can get a long screwdriver blade onto the injectors, use this to have a listen to each one just after start up. If one sounds different to the others it could be sticking (open or shut). Consider having the injectors cleaned:
www.injectorcleaning.co.uk/index.htm
I did and it made a big difference
A taxi is unlikely to be coked up, but could it be suffering from some coke on a valve or two which only shows up when cold (Rover T series 2.0 used to do this). Try running the car on 5 tanks of Shell Optimax or BP Ultimate. this costs more, but he may get better economy to offset this if he drives moderately. Over a decent mileage this should help to clean out the inside of the engine if it needs it.
Also check the battery voltage just after start up. If the battery or alternator is dying and pulling the voltage down too far, the engine ECU may take exception or you may be getting weak sparks.
Try new spark plugs.
Have a cold and warm compression test conducted.
Plus, of course, there could be numerous other causes but I'll bet it's something small and cheap in the end!
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You are all most kind!
Thank-you!
I'll pass this on to the chap.
He's already run some injector cleaner, plus is using Shell.
Thanks again.
Hopefully I'll be able to report back on the fix.
And I'll get a free lift back from Stockton.
rg
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Just for the record. the problem turned out to be the EGR valve.
The car is a late-2000, but carrying a "personalised" R-plate, which confused both the mechanic and me.
Thanks for all the replies.
rg
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