Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Coog on 06 February 2011, 18:57:27

Title: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 06 February 2011, 18:57:27
Hi Guys,

Had my 1999 2,5V6 Omega out drifting today. All went very well for first few hours but all of a sudden I noticed a power drop (water temp gauge was up at 100 degrees), she would barely spin the wheels in first never mind second. Engine revs out but was slow to rev and felt sluggish, almost like a misfire. The engine management light also came on however I've no code reader so no idea what it is... When I switched the engine off and on again the light went out but would come on after 5mins... no other symptoms.

 I also swear the problem got less severe when the engine was cooler. Problem is not that she's not road legal and I can't test it (legally) till the next drifting event.

Can anyone recommend a code reader to use (I'm used to VAGCOM/VCDS for my VW's) or any ideas what the problem could be. Also will the code remain logged if the battery is disconnected? I disconnected the battery when packing her away and forgot that it may wipe the memory of the ECU  :-/

Sorry for so many questions  :-[  :-/

Thanks a million in advance
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Andy H on 06 February 2011, 19:04:32
Have you tried using thepaperclip test (http://www.omegaowners.com/forum/YaBB.pl?num=1189022687) to read the codes?

The Omega doesn't lose the codes when you take the battery off.

Not sure whether the paperclip trick gives you historic codes or just current fault codes :-/
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 06 February 2011, 19:39:33
Awesome

So I got:

16   Knock Signal Circuit 1
19   Incorrect RPM Signal
73   Mass Air Flow Sensor Voltage Low

Not sure if this helps but the right hand side air intake pipe had come loose just at the plenum and killed the car earlier in the day, it triggered an EML but I fixed it and the EML disappeared, also we blew a fuse for the dash which killed the air/dash/rpm/speedo.
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: cem_devecioglu on 06 February 2011, 22:07:29
19 is important.. crank sensor..
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 07 February 2011, 08:01:17
Would it cause power loss as described?

I had this part go on a 2.6 Vectra and the only symptoms were non-start when engine was hot - no power loss. Come to think of it there was one or two occasions when the Omega wouldn't start straight away but only when cold  :-/

Would crank and crank and nothing. Then pull key crank again and it'd start perfectly.

I guess it could be either of the 3 sensors individually or a combination
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: cem_devecioglu on 07 February 2011, 09:44:53
Quote
Would it cause power loss as described?

I had this part go on a 2.6 Vectra and the only symptoms were non-start when engine was hot - no power loss. Come to think of it there was one or two occasions when the Omega wouldn't start straight away but only when cold  :-/

Would crank and crank and nothing. Then pull key crank again and it'd start perfectly.

I guess it could be either of the 3 sensors individually or a combination

maf sensor error can be generated after those kind of errors.. normally when the crank sensor starts to give up wont easily give 19.. but once present,  I would start with that..

ps: there are different types of crank sensors so check the part number.. 
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 07 February 2011, 14:59:01
Will do, thanks very much mate :)
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 12 February 2011, 00:10:47
Can anyone tell me how to remove the codes so that when I do the next paperclip test it doesn't come up with the same problem?

Just realised (after a couple of hours farting about) that a ODB2 cable doesn't work with a 1999 2.5 V6  :-[
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: cem_devecioglu on 12 February 2011, 08:18:22
if I remember correctly, after some succesfull starts the codes will be cleared.. drive the car for some time..

of course if there is another problem it will stay .. if that happens the changed parts code will be cleared imo..so you can paperclip again..
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 12 February 2011, 12:37:52
Car isn't road legal but I started it and turned it off 30 times and the codes cleared on the driveway. Ran the car, revved it, let it get super hot trying to replicate same scenario as last week... really tried to get the fault again and nothing... no codes and running 100% perfect.

I know for sure that the second I head out drifting again the bloody thing will break down. Aaargh!
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 12 February 2011, 16:01:51
Ok, it's fault 19 - managed to get it to trip again. Thanks for the help guys
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 02 April 2011, 22:01:11
Replaced crank sensor with new one (VDO/Siemens IIRC) at cost of about £50ish. This worked fine and car was 100% but after 30mins hard running today the fault returned (was running brilliantly for the first while until it got really hot)  :-?

Are the siemens sensors crap or is there another reason why my Omega is killing sensors?

While I was replacing the sensor I noticed another one in there, so the one I replaced must've been fairly new too lol  :-/
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Entwood on 02 April 2011, 22:06:04
How did you route the wire ???  The sensors themselves don't often fail .. but the cable runs VERY close to the exhaust and can suffer heat damage .. the forum guide suggests routing over to the brake pipes and then down. given that both of yours have failed after some pretty intense heat getting into the engine bay .. high power, low forward speeds ... I wonder if that is the cause of your problems ??
Title: Re: Hesitation/Power Loss & EML - 2.5 V6
Post by: Coog on 02 April 2011, 22:19:39
Yeah I read the guide and cable tied the cable as far away from the exhaust as possible. It's still going to get pretty hot in there though.