I own an Omega 2.5 CD Estate (manual/petrol), first registered in January 1997, and which I have had since it was about 18 months/30k old.
It's been well maintained over the years by a first class private mechanic (who hates the car with a passion, takes it personally when there is a problem and is very proud of her when she purrs after a service!) I'm not enough of a petrol head to want to do the work myself, although don't have an aversion to getting my hands dirty, I just know my limits; but I have learned a lot about this car and its predecessor (a Ford Escort) while he has been working on them.
Back in September I noted that she was no longer starting on the button, which then morphed into not starting at all and a couple of homestart visits from the AA who diagnosed problems with the fuel pump relays. New relays didn't fix it. A mate of the mechanic who does electrics actually came out to fix the problem I had with the electric windows and ended up looking into the starting issue. He fitted a switch to manually fire the fuel pump as his modern diagnostics could only find an issue with the earthing from the ECU to the relays.
All this took time to occur, partly because the car is mostly driven only one day a week at the moment.
Finally the mechanic unearthed his ancient diagnostic computer and diagnosed the crank sensor.
As usual Vauxhall gave him the wrong part, initially supplying him with a sensor with the "square" connector (actually, over the years my car has never taken the parts suggested by the reg/vin #s), then a Siemens sensor. The mechanic took a Bosch sensor with an oval connector off the car, so - having read the guide on here - I quoted him the part number for the facelift models and that's what he fitted (and it matches the part # on the sensor he removed) - except that he tells me that the new sensor was not labelled Bosch; there was no apparent manufacturer labelling to it at all.
The day he fitted it he had the engine running like a dream again and starting instantaneously.
The mechanic is based close to my parent's house and does the work on your drive, so he does the work at their house. Unfortunately it was two days later when I got the train over to pick the car up and as soon as I started it I noticed three things.
1) The dashboard display, which has been steadily losing pixels over the years, was much improved (although that didn't last!)
2) Although the engine fired up immediately, there was a whistle or a whine to be heard as it did so
3) The engine was wrong from the moment it fired up (that was where my heart sank)
I had to find the mechanic at that day's job to pay him and when I pulled up his heart sank too as he thought it sounded like my car, but the engine was misfiring.
When he changed the crank sensor (he changed both, I forget what the other one is called, off hand) the engine was drenched in condensation - an issue he said he'd had with several cars that week. Hence he thought that maybe some moisture had got into the leads/plugs. A week or so later he changed the leads and coil pack and finally the plugs: still no improvement. Plus I think the misfiring has finished off the exhaust which will only make things worse with the engine management.
The mechanic wondered if he'd managed not to reconnect one or more of the vacuum pipes properly, but he was not having a good day the day he changed the coil pack, leads, etc as he wasn't well, and was very demoralised that it was running no better at the end. As he'd pushed out other work to fit me in I tried to take the pressure off by leaving any further work into January. I don't need to drive it a great deal at the moment (although I DO need a reliable, working car). It's a ~30 mile motorway drive between home and my mother's place - and the car will do it if necessary (in fact I think it runs best at 80 at the moment!) But I did notice driving home that I can't get hot air down to the footwells at the moment which, I believe, is a pipe connection issue (and it would be terrific if this was the answer to it all).
The whistle/whine can only be heard inside the cab, with the door shut - presumably the engine noise masks it outside the car - and does seem to track the throttle.
To me, it sounds horribly as if the ECU is not mating with the new sensor, based on the FAQs to be found here on the subject.
Anyone got any insight to offer?
Thanks
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Topic: Mis-firing following crank sensor replacement (Read 2288 times)