- Discussion about smooth running test: , ).
Fluid flush procedure: ) requires the several components to be synchronised. Some of these components are unable to be re-programmed or reprogramming requires expensive equipment. The components which need to be synchronised are: DME, EWS control unit and the electronic chip inside the ignition key. The easiest method to maintain synchonisation is to send the new DME, EWS and the car key to a specialist for re-coding (MichaelK5990 thread, 766jack thread). Having the existing key re-coded avoids the need to replace all the locks in the car. Another option is use the DME from your old engine on your new engine.
Even matched EWS components can need re-syncing (HTK12 post).
Replacement with identical engine:
Using a replacement engine of the exact same specification (same family, same capacity, same vanos configuration) enables the old engine's electronics to be used with the new engine (1). This avoids the complications involved with modifying the EWS system.
Alternative sources for replacement engines:
- M52: E36, E38 (pre September 1998 only) or Z3 (pre September 1998) (1)
- M52TU: E46, E38 (post September 1998 only), Z3 (post September 1998)
- M54: E46, Z3 (3.0L only), Z4 (pre September 2006), E53. Note: the E60 and E83 models also used the M54 engine, however they started production after the E39 was discontinued, therefore there may be changes which are incompatible with the E39
- M62: E38 (pre September 1998 only), E31 (4.4L only)
- M62TU: E38 (post September 1998 only), E53 (pre July 2003 only)
Note that coding is required when installing an engine from an automatic car into a manual car, and potentially vice-versa.
Replacement with same engine family, but different engine specification:
This section described engine swaps within the same family (eg M52, M54, M60 or M62). Although the M52 and M54 engines are similar in many ways (similarly, the M60 has many similarities with the M62), unfortunately the small differences may cause difficulties for an engine conversion (1). Therefore, it is often much more straightforward to use a replacement engine from the same family. Nonetheless, there are still challenges when remaining in the same engine family. Therefore, in addition to the issues noted above, the following issues should be considered.
Capacity changes require a change of engine tuning to operate at its full potential. It is possible to get the new tune coded into your old DME (2), thus avoiding EWS modifications. Also, it may be possible to 'virginize' a DME so that a new tune can be used (3). Note that sometimes the ancilleries are different for each engine capacity, for example the maf, intake, airbox are different between the M54B25 and M54B30 (4).
Changing the vanos configuration (eg replacing a single vanos M62 engine with a dual vanos M62TU engine) is considered not a practical option (1, 2, 3), since it would require extensive modification to the cars electronics.
Engine swaps for power increase
"Anything is possible, the question is if it is worth your time and money. I have seen someone swap an engine out of a 2006 M3 into a 1989 M3. Was it really cool and fast? Yes. Was it really worth spending almost $20k for it? No. For that kind of money he could have built up an impressive euro S50 and blown away his current setup" -Jimmys530i
The issues discussed above in replacing a broken engine all apply, plus added complications due to differences in how the car is configured for each engine.
E39 engines- 6 cyl:
- BMW M52TU replacement of M52: discussion thread, discussion thread
- BMW M54 replacement of M52: [emailprotected] build thread
- BMW M54 replacement of M52TU: raymond3080 build thread (note that this build retrofitted the M52TU intake onto the M54 engine), flashmeow build thread (similarly, this build used the M52TU DME on the M54 engine),Irogers80 build thread, discussion thread, discussion thread. As some of the above builds show, the M54 engine can run on an M52TU DME, which avoids many of the electronic complications. However, the M54 engine will not be running optimally in this state.
- BMW M52 replacement of M54: rmb213 discussion thread
- BMW M52TU replacement of M54: discussion thread
E39 engines- V8:
For 6 cylinder owners, it will probably be cheaper to trade in your car and buy a V8 E39 than to do a V8 engine swap on a 6 cylinder car (1, 2, 3, 4, 5).
- BMW M62TU replacement of M62: Theoretically, this swap is similar to M54 replacement of M52TU (see above).
- BMW S62: This swap is expected to be very difficult (1, 2)
- Chevrolet LS1: rao thread, Mutty build thread, RVAE34 build thread, Stutts115 build thread, M5_Hunter build thread. The LS1 is probably the most popular swap involving a non-BMW engine.
- other Chevrolet V8 engines: nsogiba LQ9 thread, James39 LQ4 thread
- Nissan RB26: Mda185 post
- Toyota 2JZ: bmw_2jz thread, Mr535i build thread, Oz923 thread, 930chas build thread