[Garagedood]

Hello VX people. Have popped in to see if anyone has heard of this issue. I have "vauxcheck" from Gendan on my garage Pc although I no longer have my Omega v6 2.6. Anyway nearly a year ago the check light lit up on the sons girlfriends 2006 corsa c 1.2 twin port . No problem, plug in the computer and O2 sensor 1 fault code came up, replaced that and all was well for a few weeks when the light came on again, plugged it in again, this time 02 sensor 2 is the culprit, replaced that and all was well for a good few months. A couple of weeks ago the light was on again, plugged it in, 02 sensor 1 again. Suspecting her commute of only 2-3 miles to be the problem, car never warming up fully and always running rich having contaminated the sensor I replaced it again. The light came on again after a few days and I had to admit I was out of ideas. A free check at a local independent suggested 02 sensor 2. Not convinced I urged her to go to the main dealer for a proper diagnostic. She did this and they say the op relief valve is faulty and there is a problem with the 02 sensor circuit- the sensors themselves are apparently fine.i can not think of any connection between the two myself although they told her there is. Have looked on VOSA to see if there was any recalls and have searched the net for any relevant tech service bulletins or campaigns but can't find anything, anyone have any ideas????

 

[Garagedood]

Further details

Seem to have been given duff info, it seems that the oil pressure SENSOR is doing what they all seem to do, ie leaking! I did notice that it was weeping a bit but it is not actually as bad as some I have seen and does not need immediate attention to my mind. it is only a only a two minute job to change anyway for only a couple of pounds.They seem to be suggesting that this is somehow leaking on to the 02 sensor loom ( it isn't ) causing the check light to come on and log sensor faults, this apparently means that the harness needs to be replaced. I suspect some main dealer jiggerypokery here in that there is a known issue with this component that would normally have been rectified while the car has been in for service. This is what I was hoping to find out from this forum. My experience with other makers has been much more positive, the family truck is a 06 Passat 2.0 tdi estate. In the last 18 months or so it has been recalled twice, once for a new fuel pump and next time to have the injectors replaced free of charge. I must add that I had no sign of the problems that prompted the recalls but I am very happy to have the new parts, great service from VW especially considering the car was six years old with nearly 140k on the clock. We will see what transpires when the corsa comes back from the shop next week.

 

[Garagedood]

For those who might be interested the md workshop maintains that the leaking oil pressure switch has somehow contaminated the engine ecu harness resulting in spurious fault codes being flagged. Replacement of the harness at a cost of over £600 was to have cured the problem but within 24 hours the eml is back on with O2 sensor 2 being flagged up on my vauxcheck. Hey ho back to the dealers we go.....

 

[taurus]

I seem to have missed your earlier posts - the oil switch is a known issue and they leak for fun, but since they are cheap and simple to replace it's not something to get excited about.

But whilst leaking oil switches are common the idea that it causes the O2 system to malfunction is a new one - and as you have found out - incorrect to boot.

If the no.2 O2 sensor is repeatedly coming up and it's been replaced with a decent quality unit then chances are it's either an exhaust problem or the cat failing due to all those short journeys.

In terms of your query re. recalls - they must know the oil switch is weak but there's never been a recall on them.

 

[SeaMonkey]

Similar problem.
A few weeks ago I changed the O2 sensor having checked the car after the MIL light came on. I noticed at the time oil inside the sensor connector which I cleaned and all was well for a while. A week later the Oil Pressure Switch failed which I replaced.
All was well for a couple of months then the MIL light came back on, on the dashboard. The fault code was again the pre cat O2 sensor. On separating the connector it again had engine oil inside. I thoroughly cleaned the sensor with WD40 and waited for this to dry out. After 30 minutes there was still signs of oil on a clean tissue in the form of 4 spot which lined up to the connector pins. There was absolutely no oil externally in the connector or harness.
After cleaning the connector as best I could I reconnected and the MIL light has gone out.
I know it is possible for oil to get inside the harness because Mercedes did a recall on this.
Has anyone else had a similar issue with the oil switch putting oil into the harness and giving an O2 sensor fault code. Is the only solution an engine harness change.

 

[Vegas]

What's a mil light?

What car is this? You mention Mercedes?