Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: GaryBC on 19 December 2011, 11:14:17
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Late last night (1am, exterior temp 2.5 deg C below freezing) started ok but, after a minute or two, it started hunting between about 1,000 and 1,400 rpm. After setting off it settled down. All ok from then on - I just put it down to "one of those things"! However......
This morning (7am, similar ext temp) it did the same thing but this time it didn't settle down. High idle when in gear (it's an auto) and hunting when in neutral or park. It also holds the gear changes longer - almost as if the engine is still trying to warm up (like it isn't getting the correct engine temp data?). Makes driving on icy roads slightly more 'interesting' than I'd like!
I topped up the engine oil at the weekend. Could I have disturbed a sensor connection or vac line maybe? It was fine until last night - this one has come completely out of the blue!
Cheers,
Gaz
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did you spill some oil in plug wells???
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Don't think so but will check.
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Two thirds of the way home last night (c10 miles) it suddenly righted itself, and it was fine this morning!
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was ext temperature higher this morning when everything was ok ?
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Yes, it was. So I'm on the lookout for it happening again next time it's at or below freezing. Obviously I didn't disturb anything when I topped up the oil and I didn't spill any in the plug wells. So if it comes back I must have a dodgy sensor somewhere.
In which case, any ideas as to what sensor(s) could be likely candidates?
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might not be sensor, it could be ht related something breaking down due to coldness :-\
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what engine is it ?
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what engine is it ?
Finally... ;D
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what engine is it ?
If it was that then surely the problem would go away once the engine gets hot?
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what engine is it ?
Finally... ;D
2.5v6 petrol
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Temp sensor behind bumper on the blink :-\
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The indicated outside temp display on the dash seems ok - does the engine management computer take a feed from there too?
Where is it? If it's easy to get at I can re-seat the connector.
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It sits behind the front bumper below the washer bottle :y
Not sure about PFL, but Facelift access is easy enough with bonnet open :y
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The indicated outside temp display on the dash seems ok - does the engine management computer take a feed from there too?
Where is it? If it's easy to get at I can re-seat the connector.
No. ;)
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Temp sensor behind bumper on the blink :-\
:-\ Erm......is not the intake-air temperature sensor located in the area around the MAF?.....I thought the under-bumper one was just for the display?.....I might be wrong, though. :-[
Having recently suffered faulty crank-sensor woes, I also noted that the various symptoms (no/low/oddly-high/hunting idle) were considerably worse on cold mornings; might this perhaps, be warning of a failing crank sensor?
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No indeed, engine temp is taken from the spade connector to brass coolant sensor on the coolant bridge under plenum. These can corrode /fall off.
But check for minor air leaks, such as loose icv to plenum, breather pipes ect.
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Intake air temperature is indeed a separate sensor near the MAF on pre-DBW V6s. On DBW V6s, it's built into the MAF sensor itself.
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The indicated outside temp display on the dash seems ok - does the engine management computer take a feed from there too?
Where is it? If it's easy to get at I can re-seat the connector.
No. ;)
Not a lot of point fiddling with it then! But it begs the next (obvious?) question of, "so where does the engine controller get it's temp feeds from - specifically the engine temp (as opposed to ambient)?" The way I figure it it is this feed that is probably causing the problem as the high and erratic idle suggests it thinks it is still stone cold. (Although I know that nothing on a Miggy is ever as simple as that!!)
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No indeed, engine temp is taken from the spade connector to brass coolant sensor on the coolant bridge under plenum. These can corrode /fall off.
But check for minor air leaks, such as loose icv to plenum, breather pipes ect.
The second point sounds like my best initial bet. If the connector came adrift the problem wouldn't have corrected itself. (Mind you - thinking about it - neither would an air leak spontaneously fix itself either!) Could a failed (or failing) temp sensor be the cause of my problem?
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I believe I remember seeing an engine fault code for 'coolant temperature voltage high/low' :-\
Have you "paperclipped" for any codes?
http://www.omegaowners.com/forum/index.php?topic=90524.0 (http://www.omegaowners.com/forum/index.php?topic=90524.0)
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The indicated outside temp display on the dash seems ok - does the engine management computer take a feed from there too?
Where is it? If it's easy to get at I can re-seat the connector.
No. ;)
New thing learnt :y