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E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

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  #1  
Old 03-13-2011, 01:57 PM
Takechan Takechan is offline
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Location: Scandinavia
 
Join Date: Mar 2009
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Mein Auto: BMW E39 520i (M52B25)
VCG before or after engine swap?

I'm in the middle of preparing for an engine swap (M52B20->M52B25).

As i'm going to replace the VCG (it's kinda leaky) i'm not sure if I should do this before or after i've swapped the engine. While it's easier before installing the new engine, i'm afraid the hoist if lifted from engine hook (near vanos) will stress the gasket/seal?

Oh and another thing, the rear diff is 3,46 now but the engine came from a 523 that supposed has 3,23 or in special cases (3,46) - what would it mean if I drove around with a 3,43 ratio (higher) than normal spec? I assume revs / speed will be unchanged?
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  #2  
Old 03-13-2011, 03:46 PM
bobdmac bobdmac is offline
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Since the replacement engine came from a car with a different rear end, you might need to reprogram your powertrain control module, which handles the interaction between the engine and transmission. Revs/speed would not change for your car from what you had with the previous engine, but if the donor car had a different rear end, it makes me wonder whether your transmission also has different gear ratios.
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  #3  
Old 03-13-2011, 04:05 PM
Takechan Takechan is offline
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Location: Scandinavia
 
Join Date: Mar 2009
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Mein Auto: BMW E39 520i (M52B25)
I forgot to say that my car has a manual gearbox and that the new engine came from one with steptronic.

According to this calculator I will end up with 2755 RPM @ 60 MPH with the 3.46 ratio and 2572 RPM @ 60 MPH with a 3.23 ratio. So while the RPM / mph would be unaltered from my current setup the 0.5L extra may cause my consumption to rise marginally?

I usually drive around max 30.28 mph so the RPM difference would only be 1712-1598 = 114 RPM compared to a stock 523i.

Last edited by Takechan; 03-13-2011 at 04:09 PM.
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  #4  
Old 03-13-2011, 08:56 PM
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bluebee bluebee is offline
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Location: San Jose, California
 
Join Date: Mar 2008
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Mein Auto: 02 BMW 525i M54 auto 130K
This new thread today 'may' have information on swapping engines:
- What engine combinations are known to work in the E39 when the need arises to replace
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  #5  
Old 03-30-2011, 05:46 PM
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Shires Shires is offline
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Location: Dublin, Ireland
 
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Mein Auto: '03 E39 520I 2.2 M/T
Quote:
Originally Posted by Takechan View Post
I forgot to say that my car has a manual gearbox and that the new engine came from one with steptronic.

According to this calculator I will end up with 2755 RPM @ 60 MPH with the 3.46 ratio and 2572 RPM @ 60 MPH with a 3.23 ratio. So while the RPM / mph would be unaltered from my current setup the 0.5L extra may cause my consumption to rise marginally?

I usually drive around max 30.28 mph so the RPM difference would only be 1712-1598 = 114 RPM compared to a stock 523i.
Higher revs doesn't always mean higher consumption - I believe that engines have different sweet spots depending on revs and what you're doing with the throttle (near closed, open, full, etc). Also bear in mind that you can shift earlier with a 3.46 rear.

Are you swapping the DME (engine control unit) or having it reprogrammed? Re: the diff in your car, the 520i has smaller CV joints on the half-shafts compared to the other I6s so maybe be careful if towing etc. with your new engine!

Let us know how you get on with your engine swap!
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  #6  
Old 03-31-2011, 05:57 AM
poolman poolman is offline
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You don't need to program a thing--stay away from stuff like that. On the engine swap, go ahead and install the new valve cover gasket while the engine is out. You can get to everything with ease. You really should
install new Vanos seals and oil filter housing and CCV valve while the engine is out also. It would be a breeze
to do all this when you can get to everything. My 2 cents
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  #7  
Old 03-31-2011, 11:12 AM
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Shires Shires is offline
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Location: Dublin, Ireland
 
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Mein Auto: '03 E39 520I 2.2 M/T
Quote:
Originally Posted by poolman View Post
You don't need to program a thing--stay away from stuff like that
You don't think it will run lean on a DME mapped for a 2.0 engine?
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  #8  
Old 03-31-2011, 12:20 PM
Takechan Takechan is offline
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Location: Scandinavia
 
Join Date: Mar 2009
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Mein Auto: BMW E39 520i (M52B25)
I am going to reprogram the DME to a 2.5L, they use same part #, but it has a different programmed #.

Also, I removed the VCG on the new engine the other day (cf. picture) and in the middle of removing the old engine as we speak.



The annoying E10, E12, and E14 torx bolts were indeed a pain to remove from the tranny, but it was possible to remove the hardest from the top of the car. One of the bolts (E14) however broke upon removal :'(

It's still fun though
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  #9  
Old 03-31-2011, 12:45 PM
bobdmac bobdmac is offline
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Location: Back in Oaktown, Yay Area
 
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Mein Auto: 2001 540i/6, '90 BMW k75s
Quote:
Originally Posted by Takechan View Post
The annoying E10, E12, and E14 torx bolts were indeed a pain to remove from the tranny, but it was possible to remove the hardest from the top of the car. One of the bolts (E14) however broke upon removal :'(

It's still fun though
It's an adventure, isn't it? By the way, I believe those Torx bolts are intended for one-time use, according to the Bentley manual, and should be replaced
.
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  #10  
Old 03-31-2011, 01:50 PM
Takechan Takechan is offline
E39 fanboi
Location: Scandinavia
 
Join Date: Mar 2009
Posts: 244
Mein Auto: BMW E39 520i (M52B25)
Thanks for that information.

I think i'll replace them all then

Oh and the MAF is not the same, which is another reason why it's necessary to reprogram the DME.
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  #11  
Old 04-10-2011, 12:49 PM
Takechan Takechan is offline
E39 fanboi
Location: Scandinavia
 
Join Date: Mar 2009
Posts: 244
Mein Auto: BMW E39 520i (M52B25)
Ok I managed to swap the engine successfully

It wasn't uneventful:

- I dropped the engine when hoisting it out of the engine bay (the rear hook broke)
- A screw from bellhousing to engine (old) snapped
- A screw from the clutch to flywheel broke (I had to use the old flywheel so it was critical I could reuse it)
- Aligning the transmission to the engine when installing the new was pretty difficult
- Car wouldn't start because a ground wire was loose
- The first flash of the DME failed so the car couldn't start...

Anyway, all in all the most difficult job I've ever done. Had to do it in the driveway hehe.

I'm pretty happy with the result. I've gone from a M52B20 to a M52B25 with upgraded DME (to correct map) and kept my old differential (3.46) so it's one hell of a difference.



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