Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: soslow on 06 January 2015, 08:28:08

Title: Omega 3.0 to 2.5
Post by: soslow on 06 January 2015, 08:28:08
Hello everyone!
Recently had been offered a really cheap x30xe Omega with auto gearbox. Previous owner had oiling problems and now the engine is dead. He says that the crankshaft died because of the oiling problem.

Its difficult to find a 3.0 engine, but the 2.5 is really cheap, thats why im thinking about swaping those.

So the question is: Does the 2.5 engine fit to 3.0 auto gearbox? What else is different between these two engines and what other parts do i need?

And maybe i can just take the botom from 2.5 engine, leave the 3.0 heads, so i dont have to change ECU and do the wiring?

P.S. Sorry if the questions are dumb, i just never had to deal with omegas and wanted to know wich would be the easiest and cheapest solution.
Will be thankful for any advice. ;)
Title: Re: Omega 3.0 to 2.5
Post by: 05omegav6 on 06 January 2015, 08:35:30
Straight swap :y obviously it will be alot slower, but connections are all the same :y

Ideally, keep the 3.0 exhaust manifolds, and if you're able, swap the cams from the 3.0 as well, that way you'll keep some of the 3.0s power. Wouldn't bother swapping the heads, personally, just the cams... Be sensible to swap all the sensors over as well, that way the car won't notice the difference electrically speaking.

3.0 gearbox is stronger, but visually identical, so 2.5 will bolt straight to it as well...

Nice little project :y
Title: Re: Omega 3.0 to 2.5
Post by: biggriffin on 06 January 2015, 08:38:00
Put 3.0L cams, inlet tract,and diveder, on to 2.5 that give about another 20+hp, also fit gearbox from 3.0L as its a stronger box.  :)
Title: Re: Omega 3.0 to 2.5
Post by: biggriffin on 06 January 2015, 08:40:48
Only difference in sensors is crank sensor.(plugs). Knock,water temp,coolent all same sensor. Might want to swap chips over if the push in type.
Title: Re: Omega 3.0 to 2.5
Post by: soslow on 06 January 2015, 09:07:39
These are nice news, because current engine has new alternator and starter motor and I was hoping to use these.  :y

If i change sensors, i can keep the 3.0 ecu, correct?

And what type of chips should be swaped?  :)
Title: Re: Omega 3.0 to 2.5
Post by: 05omegav6 on 06 January 2015, 10:12:03
These are nice news, because current engine has new alternator and starter motor and I was hoping to use these.  :y

If i change sensors, i can keep the 3.0 ecu, correct?

And what type of chips should be swaped?  :)
That's correct :y

Biggriffin was referring to the ecu chip, but might not be possible... Wouldn't worry about it tbh ;)
Title: Re: Omega 3.0 to 2.5
Post by: zirk on 06 January 2015, 11:35:23
These are nice news, because current engine has new alternator and starter motor and I was hoping to use these.  :y

If i change sensors, i can keep the 3.0 ecu, correct?

And what type of chips should be swaped?  :)
Its an Eprom 27XXXX type, from memory its the only Chip that removes from the plug in Holder on the CCt board (if its not soldered in).

Otherwise just swap the whole ECU Module + the Immobilizer Module (under the Ignition Barrel) and the Transponder Chips inside the Key Fobs, 15 -20 mins Job.   

Title: Re: Omega 3.0 to 2.5
Post by: soslow on 06 January 2015, 12:10:03
Thank you all for help, its very useful!  :y

Maybe there is some other bits that I should check once the engine is out? Any typical V6 problems?  ;D

Ohhh and the most important thing - where on the engine i can see  which  engine is it? Is there a code or name on side of the block like other cars? Heard something about different intake manifold pipe sizes too.
Just heard from one of the local scrap yard worker, that most of 3.0 engines for sale in my area are 2.5s, but the sellers think they are 3.0s and try to sell like one of those  ;D
Title: Re: Omega 3.0 to 2.5
Post by: Webby the Bear on 06 January 2015, 12:31:47
Get the sump off and clear the oil strainer. :)
Title: Re: Omega 3.0 to 2.5
Post by: Webby the Bear on 06 January 2015, 13:16:22
..and may as well replace all gaskets.... HG, exh. manifolds, cam seals etc. as its out on the bench :)
Title: Re: Omega 3.0 to 2.5
Post by: zirk on 06 January 2015, 14:19:11

Maybe there is some other bits that I should check once the engine is out? Any typical V6 problems?  ;D

Cam Belt and Tensioners are important on the V6 (every 40K (Miles) or 4 Years is recommended here).

Other possible issues are, Water Pump, Oil Cooler, Breathers, Rocker (Cam Covers) Seals, to name a few, but can be done relatively easy with the Engine in situ if and when they fail.   
Title: Re: Omega 3.0 to 2.5
Post by: soslow on 06 January 2015, 17:50:08
Found this http://oldsite.omegaowners.com//forum/YaBB.pl?num=1297252936

And now im considering a Saab 3.0 engine without a turbo. It will have like 20 hp less in non-turbo version because of the low compresion, but this engine is way easier to get.
How do you think this will also be a plug-and-play swap or this could turn out worse because of the different ECU that Saab is using? Or better just to put a 2.5 in it?
Anyone done it maybe?

P.S.
Thanks to everyone for sharing opinions  :y
Title: Re: Omega 3.0 to 2.5
Post by: 05omegav6 on 06 January 2015, 17:53:44
Essentially the same engine, so again swap sensors etc from Omega 3.0 to the Saab lump and bung it in...
Title: Re: Omega 3.0 to 2.5
Post by: andyc on 06 January 2015, 19:13:12
I would want to check the 30 cams carefully. If the crank sized due to oil feed/pressure problems then the cams could have picked up as well.

Andy
Title: Re: Omega 3.0 to 2.5
Post by: soslow on 06 January 2015, 20:38:28
I would want to check the 30 cams carefully. If the crank sized due to oil feed/pressure problems then the cams could have picked up as well.

Andy

Jep, have been thinking about this one too  ;) Just need to take the engine apart as quick as possible to see the situation down there...