Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Pirvan on 21 November 2013, 08:52:15

Title: Mystery problem. Fails to start once in a while...
Post by: Pirvan on 21 November 2013, 08:52:15
Hi Omega Experts!

I have a problem with my Omega that's even got my local garage stomped.

The car is a 2000 Omega 2.5 V6 petrol, Manual gear.

Problem
The problem is that it on occation won't start. When it does get started, it runs flawlessly.
- If I put it in gear when attempting to start it and lifts clutch and applies gas, it actually moves (forward or backward, depending on putting it in 1st or reverse) but it doesn't come on.
- If it gets pushed or drawn in this instance and I crank it again, it will start.
- I've had the problem occur even after driving for a while and then stopping for 5 minutes for gas or dropping someone off, and then coming back to it, it doesn't start.
- When I've gotten it towed to the garage (twice) it has started right away again, simply by being moved... They're saying it's hard to find a problem when everything appears to work. Fair enough.
- Fault-codes - there are no faults except for a lambda sensor (O2 sensor) which appears out of order. Could this cause the issue?

Background
- The car is recently serviced with oil-change, filters, sparkplugs etc.
- It was repaired for the above issue as well, as there were two of the cylinders/valves to the sparkplugs that leaked in oil. The leaks were fixed by replacing the parts and installing new sparkplugs. Also, a power distributer was changed since it still wasn't starting after this fix. After this was done, it worked well for a while, only to have the problem happen again. Then it went back to the garage, they couldn't find the problem/car worked perfectly and until now again, where it died on me again.

---
Question(s)
What in the name of all that is holy is going on? It usually starts but sometimes it doesn't? Is this a crank-sensor issue as is so famously mentioned a lot on this site or what do you guys believe it is?

Any help wold be greatly appreciated, thank you. :)
Title: Re: Mystery problem. Fails to start once in a while...
Post by: Webby the Bear on 21 November 2013, 08:59:14
Hi,

When you say it wont start... is it cranking/no start or just dead? I'm presuming it's cranking (turning over) so you need to check for spark, fuel delivery and compression :)
Title: Re: Mystery problem. Fails to start once in a while...
Post by: chrisgixer on 21 November 2013, 09:09:02
Faulty crank sensor.
Title: Re: Mystery problem. Fails to start once in a while...
Post by: Webby the Bear on 21 November 2013, 09:11:58
Was going to mention that Chris, but I thought that was more to do with cutting out. But thinking about it, it will not start if it hasn't got a TDC reference...

so to OP.... faulty crank sensor  ;D
Title: Re: Mystery problem. Fails to start once in a while...
Post by: Pirvan on 21 November 2013, 09:14:19
Alright, quick follow up. It is cranking like a mofo and if gets pushed or towed, it will actually start and just keep running. It never stalls or anything else.

Does this still confirm the crank sensor that's posted in the FAQ? Which one will I need to replace it with? I'm sorry I'm not that car-saavy so just wanted to ask to be sure. Also, how much does the part cost and how much time does it take to replace?
Title: Re: Mystery problem. Fails to start once in a while...
Post by: YZ250 on 21 November 2013, 09:16:32

-........ I've had the problem occur even after driving for a while and then stopping for 5 minutes for gas or dropping someone off, and then coming back to it, it doesn't start.......


That does sound like classic crank sensor symptoms.  :y

They very often start again when the engine has cooled down a bit............or just as the recovery vehicle turns up.  ::) :)
Title: Re: Mystery problem. Fails to start once in a while...
Post by: chrisgixer on 21 November 2013, 09:25:59
Was going to mention that Chris, but I thought that was more to do with cutting out. But thinking about it, it will not start if it hasn't got a TDC reference...

so to OP.... faulty crank sensor  ;D

Yes stalling at tick over will be icv.

Stalling under power will be crank sensor, as the icv is over ridden by the throttle, but this is rare going by posts here.


Typical cs failure, cranking but not firing. Usually intermittent.

Replace with GENUINE part from a DEALER, to avoid pattern copies known to be shite.

Title: Re: Mystery problem. Fails to start once in a while...
Post by: chrisgixer on 21 November 2013, 09:27:47
To the op, have a little search on here re crank sensor. You'll find all you require. :y
Title: Re: Mystery problem. Fails to start once in a while...
Post by: YZ250 on 21 November 2013, 09:29:37
Price depends on the plug shape.  :y


Crankshaft Sensors

Application    Description    Part No.    Retail    Trade    Trade Club   
2.5i 24v V6 - X25XE       90492006    £87.50    £78.75   £68.24   

2.5i 24v V6 - X25XE       90492061    £65.50    £58.96   £51.00   


Title: Re: Mystery problem. Fails to start once in a while...
Post by: Gaffers on 21 November 2013, 09:40:20
Faulty crank sensor.

+1.   Classic symptoms :y
Title: Re: Mystery problem. Fails to start once in a while...
Post by: Pirvan on 21 November 2013, 09:55:30
Thanks guys, will run with this. My awesome mechanic will be on this. :)
Title: Re: Mystery problem. Fails to start once in a while...
Post by: chrisgixer on 21 November 2013, 10:19:56
Thanks guys, will run with this. My awesome mechanic will be on this. :)

There is a guide, not to hard diy, save yourself some cash.

The dealer parts man may ask what plug shape the car has, so somebody might need to check before purchasing.
Title: Re: Mystery problem. Fails to start once in a while...
Post by: dbug on 21 November 2013, 22:43:09
Yep agreed crank sensor on way out - yours is probably the rounded plug which I believe is part no 90492061     ;)  Easy to check though :)