BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      10-06-2020, 08:43 PM   #1
BikeNHV
New Member
2
Rep
19
Posts

Drives: 2009 128i
Join Date: Mar 2017
Location: CT

iTrader: (0)

Theoretical n51 to n52 swap

Fairly new here despite owning an 09 128i N51/6 speed for over 5 years now. Been browsing various threads absorbing info, but haven't seen this covered exactly.

Let's say, in theory, my N51 died. Seems logical to swap in an N52 longblock and retain the 3SM for an instant upgrade (assuming a proper tune).

If it was your car, what else would you do to that new-to-you N52 block? Or do to something other than the engine that's more convenient while the engine is out?


Parts list off the top of my head:
- Low-mileage N52 longblock - any particular years or donor cars preferable?
- 3SM swapped over from the N51
- MILVs
- Header - worth it or not?
- Tune that will play well with all remaining SULEV stuff in the car.
- Single-mass flywheel and new clutch.
- Engine mounts - are the aftermarket options worthwhile, or just refresh with new stock mounts?
- What else?
Appreciate 0
      10-09-2020, 01:13 PM   #2
wayman519
Second Lieutenant
Canada
65
Rep
244
Posts

Drives: E82 N52 6MT A51
Join Date: Apr 2012
Location: Canada

iTrader: (0)

Garage List
2009 128i  [0.00]
- Low-mileage N52 longblock - any particular years or donor cars preferable?

Engines built between September 2009 to November 2011 need the vanos bolts replaced to prevent catastrophe failure
https://static.nhtsa.gov/odi/rcl/201...4V176-2716.pdf


Engines built prior to 2009 have cam ledge seal issues that require complete head replacement if the grooves are worn. Engines with this issue will suffer power loss and vanos faults.

https://static.nhtsa.gov/odi/tsbs/20...32779-8218.pdf
Appreciate 0
      10-12-2020, 11:38 AM   #3
BikeNHV
New Member
2
Rep
19
Posts

Drives: 2009 128i
Join Date: Mar 2017
Location: CT

iTrader: (0)

Thanks for those! Hadn't heard about those potential issues. Seems like the vanos bolt issue is easily corrected. Would be a no-brainer to take care of while the engine is on a stand, as well as all the typical oil leak locations.
Appreciate 0
      10-22-2020, 10:41 PM   #4
Jeb_
Private
57
Rep
99
Posts

Drives: 2011 128i
Join Date: Jun 2016
Location: NC

iTrader: (0)

Had my N51 eat a bearing about a year ago and had this done. I left it at the swapping over the 3SM and MILVS. There was definitely a noticeable increase in power but I got used to it pretty quickly. I'll probably do headers sooner or later.

Depending on the age of the donor motor, I'd take the opportunity to do as much of the PITA maintenance items with the engine out. A water water pump service was performed right before the engine failure so I had that moved over to the new engine. Even though I was told the donor's oil pan wasn't leaking, I just changed my oil for the second time since the swap and noticed a leak so I'm kicking myself for not having the oil pan re-sealed when it was convenient.
Appreciate 0
      10-23-2020, 09:28 AM   #5
BikeNHV
New Member
2
Rep
19
Posts

Drives: 2009 128i
Join Date: Mar 2017
Location: CT

iTrader: (0)

Good info. What did you use for a tune?
Appreciate 0
      10-23-2020, 06:20 PM   #6
Jeb_
Private
57
Rep
99
Posts

Drives: 2011 128i
Join Date: Jun 2016
Location: NC

iTrader: (0)

Quote:
Originally Posted by BikeNHV View Post
Good info. What did you use for a tune?
BPC. They were the ones doing the work on the car and handled the tune as well. So I can't speak to how involved the process is or if anything additional is required for the N51 to N52 swap over their normal tune.
Appreciate 0
      10-23-2020, 07:53 PM   #7
BikeNHV
New Member
2
Rep
19
Posts

Drives: 2009 128i
Join Date: Mar 2017
Location: CT

iTrader: (0)

Good to know. I'm basically trying to figure out if there's any non-compatibility issues with the SULEV parts (radiator with an extra sensor, special gas tank, etc), but it sounds like its a non-issue.
Appreciate 0
      10-24-2020, 02:31 PM   #8
WDE82
Lieutenant
307
Rep
535
Posts

Drives: '13 128i 3-pedal
Join Date: Aug 2015
Location: Huntsville, AL

iTrader: (0)

I would imagine the DME needs to be coded for N52 vs N51. Of course, the tune for the 3SM probably takes care of that.

Definitely ALL oil seals should be done, maybe even the rear and front main seals if that's not too hard. The oil pan WILL leak eventually. You'll get the VCG with the MILVS install.

Maybe consider putting in the oil cooler OFHG and install the air oil cooler from the 135i? If you're going to track it, it's 100% necessary.
__________________
Appreciate 0
      10-24-2020, 10:11 PM   #9
BikeNHV
New Member
2
Rep
19
Posts

Drives: 2009 128i
Join Date: Mar 2017
Location: CT

iTrader: (0)

Totally agree on the oil seals. My N51 has followed the expected sequence of oil leaks. OFHG @ 69k (previous owner), VCG @ 91k, and the oil pan has been leaking since around 105k. Still is at 121k because I've done nothing about it.

Seems logical to do the mains as well. Knowing myself, I'd be taking everything apart to inspect/clean anyway.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:29 PM.




1addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST