Engine Swap: M54B25 to a M54B30

[axenservices]

Hello All,
I have a 2005 z4 2.5. I would like to know if a 3.0 is a easy swap. Any insight would be great and maybe what I would need to do it.
Thanks all

 

[MACK]

You will definitely need a M54B30 engine to do it! LOL!!!

Seriously its probably more involve than you think, besides the engine and all its ancillaries including injectors and the like you will need B30 ecu or at least a remap of your existing one and possibly other stuff such as fuel pumps etc if they are a different spec then there is other things to considered such as is the B30 heavier and is this reflected in the choice of shocks and springs on a 3.0 rather than a 2.5. A rather time consuming part number comparison on REAL OEM should give you most answers.

Just clocked you only joined today, if this means you haven't bought yet for the difference in price between the older zeds its much much simpler to just buy a proper 3.0 in the first place, they tend to be higher spec as well and all come with m sport spec suspension as standard

 

[GuidoK]

M54 b30 is not heavier than the m54b25. IT's basically the same block, only different stroke (maybe a few grams difference because of the different intake, sound generator etc).
Also I don't know if the 2.5i clutch will align on the 3.0i flywheel, or that the 2.5i flywheel will fit the 3.0i crank They differ (2.5i also has the 5 speed)

But biggest problem is the ecu. You not only need the ecu, but also the ews (or recode), throttle body, maf (both differ from 2.5i).
And swapping over the ecu/ews will give the anti tamper dot in the binnacle.. so maybe swap that too (I don't know in how many modules mileage is stored)
of course if you have a complete donorcar with everything working you can swap the entire drivetrain incl keys etc. Then you can also use the 6 speed and diff with alternate gear ratio (if everything is still in good nick)
It's not disconnecting a few hoses&cables, split at the gearbox and hoist in the next engine.

 

[Z4SpPD]

From 2.0 to 2.5 Si? (Same problems?)

 

[GuidoK]

More problems I think

 

[Z4SpPD]

:slaphead:

More problems I think

 

[MACK]

no engine swap is worth the time/money on a zed when the prices are so close these days. your better off just buying a good 3.0 in the first place

 

[GuidoK]

:slaphead:

you could always go turbo with the 2.0

no engine swap is worth the time/money on a zed when the prices are so close these days.

Yes price difference is very low. If you have a 2.5 in very good condition, and are handy with the tools, and have a car lift, you could buy a wrecked 3.0 and do it yourself. That way you have all the parts (guessing a 3.0 wreck is £1k or so). But they still must be in good nick on the donor. And you'll be working a few days. And it is an opportunity to get things nice again (paint, beadblast parts etc). But if you have to ask how, you're probably not up to the job.

 

[Scooba_Steve]

Hello All,
I have a 2005 z4 2.5. I would like to know if a 3.0 is a easy swap. Any insight would be great and maybe what I would need to do it.
Thanks all

Anything is possible with money and time. The easiest swap is to buy a new car.

 

[Ewazix]

you could always go turbo with the 2.0

but deserves a :telloff:

 

[MACK]

you could always go turbo with the 2.0

but deserves a :telloff:

Why stop there, lets go the whole hog and get the E89 3.0l twin turbo in there, now that would be fun and it would certainly upset the M brigade!
But seriously it does make you wonder if it would easily slot in (engine mounts in correct positions etc) It would be one hell of an E85!

 

[cj10jeeper]

Hello All,
I have a 2005 z4 2.5. I would like to know if a 3.0 is a easy swap. Any insight would be great and maybe what I would need to do it.
Thanks all

Welcome. When you get time do post some pics and introduce yourself.

In terms of the swap, unless you have the new motor lying around and yours is dead then it's a waste of time and money. Simply buy and sell with about £1000 difference to trade.

You end up with a genuine 3.0 with 6 speed box, matched electronics, sports suspension, better car, etc, etc. You avoid all the issues and a genuine saleable car, not a hybrid.

 

[axenservices]

Hello
Thanks for all your input . It took me months to fine the car i have now. I wanted it black with red leather seats and gps. So i want want to just buy another car. I found a complete engine not a short block but everything top to bottom.

 

[simonlpearce]

Be happy with what you have. Failing that supercharger.

 

[Scooba_Steve]

Hello
Thanks for all your input . It took me months to fine the car i have now. I wanted it black with red leather seats and gps. So i want want to just buy another car. I found a complete engine not a short block but everything top to bottom.

Well you seem to have found the shell you want - if it was the car you wanted it would be a 3.0...
It would be easier to transplant those seats into a 3.0 (not quite sure why you want the GPS - it's pretty dated)

Even with all of the bits don't expect it to go smoothly; though I wish you good luck with the swap.
If I were going to do the job I'd be stripping the new engine down so it's as good as new before it went in, renewing mounts and bushings all round as well.

 

[axenservices]

thank you again for you input....
as for the gps i get lost in a wet paper bag with both ends opened

 

[cj10jeeper]

Oh dear - the dream car but with wrong engine. I see a heap of pain coming your way, but wish you luck.
Just the sort of project I love when I have a year with no pressures to get it on the road...

 

[Scooba_Steve]

thank you again for you input....
as for the gps i get lost in a wet paper bag with both ends opened

I just use my phone if need be :lol:

Look forward to seeing the results if you're determined to do it.