BMW E34 S62 Swap

[Timothy Prewitt]

(I have no idea what is up with the photos on this page of the thread. I tried replacing them with new links but they are not working. Sorry.) Check out my photo bucket for more pictures. http://s912.photobucket.com/user/Timothy_prewitt/library/?sort=3&page=1 )
I have wanted to do this swap ever since buying my first E34 540i several years ago. Several people over seas have done this swap, mostly with E34 M5s which makes the swap much more difficult. If you are an e34 owner more than likely you have done at least some research on this subject. The motor physically fits just fine, and today with so many people being able to code ECUs this swap has become a possibility for someone with the ability to read wiring diagrams or with the money to buy a custom harness from any number of dealers out there today.

I am starting the build with a 1994 BMW 540i6. I picked the car up for $1,800. I bought the motor from a 2001 BMW M5. The car is running on CCW classics. 18x8.5 front and 18x11 rears. In the pictures it is still on stock suspension which is going to change in the future.








Part of what makes this swap more difficult than most is that I live in California and have to make it completely OBDII compliant. This means stock air boxes, O2 sensors, Catalytic converters, evap system, secondary air pump, engine management, and OBDII port and check engine light capabilities. Because I have to have the stock air boxes I could not use the brake booster system. I thought about multiple different set ups and all seemed to be sub par. The e34 was one of the best braking sedans of its time and it would be a shame to mess with that very much. What I ended up doing is taking the hydroboost from the e32 750il. It is a bolt in replacement for the vacuum boost and produces just as much braking assistance and force as the vacuum boost does. Some people hate it, some people love it but it really was my only option to make this car legal.





My next task to tackle was the throttle. The e39 uses an electronic throttle. There are some options to convert the S62 to cable throttle, but it is expensive and I didn't feel like doing that. I solved this problem by using the throttle potentiometer from the same 750il that i got the hydroboost from. The e32 uses an electronic throttle that is nearly identical to the Z3M throttle that the e36 S54 guys use. I bought the throttle from a junk yard for $5 and it is a bolt in replacement on the e34. (I ended up not being able to use the e32 potentiometer, maybe if I understood it better I could have gotten it to work, but I tried multiple different wiring options and nothing worked. So I bought an e39 potentiometer. I got super lucky and found one mislabeled on Ebay for $25. )

The M5 headers fit just fine, they are almost identical to the E34 540i headers. The catalytic converter and midpipe is very similar to the e34 exhaust system. It hangs lower, but should fit fine. I haven't mounted it yet so I will still need to confirm that this will work without being to low, I am hopeful that it won't be any problem though and will bolt right in. The AC from the E39 does not bolt in to the new engine mounts from the M60, you have to use the AC from the e34. You have to delete the code for the AC out of the ECU. On the e39 the AC sends a signal to the ECU that raises the RPM when the unit is switched on. The e34 AC unit runs independent of the ECU so there are no integration issues.

Before putting the motor in I changed the rod bearings. The motor I bought had 142,993 miles on it. I've dealt with M motors on e36 M3s and e46 M3s and I have a lot of confidence in them so long as they are well taken care of. This motor was very well cared for with a lot of detailed history and recent maintenance before being removed. The only thing that hadn't been replaced recently was the rod bearings so I tackled that job since it was pretty simple while on a stand outside of the car.






After that the motor went in very easily. I have other information I can put on here, I will update occasionally. I am a full time student. Currently getting my doctorate in dental surgery and my masters in bioethics so I am extremely busy and can only work on this car on quarterly breaks. spring break I was in Honduras giving free dental care to the population in a small town outside of the capitol so I haven't done anything since Christmas. I am using Kassel Performance for the ECU programming. They are really great and personable. There are multiple people on this forum who could probably do this for you as well. Some other things that are to come, I bought polly bushings for everything that they make polly bushings for. Every bushing in the car is being replaced. New 3.15 LSD. Bilstien sports, still deciding on springs. New center support bearing. On the transmission I replaced every linkage piece, I even customized my own delrin oval shifter bushings for the shifter arm. They don't make delrin bushings for the 540i 6 speed because you can't instal them. I didn't take a picture or else I would show you why. I was able to modify delrin bushings from the 5 speed to fit. That is all for now. Hope you enjoy!

[RVAE34]

Very much excited about this. I dreamed about this swap for many years when I had my E34. And it would pretty much be the only way I would ever get another. Looking forward to updates!

[strang3majik]

I have always wanted to do this to a Hellrot e34...you beat me to it But happy for you! Its gonna be awesome.

[T444E]

You sure it's a 94 540? Looks like a 95?

[DennisCooper]

An awesome conversion in progress! I miss my E34 I used to have and will have to get another one - I've got my eye on a couple examples over here!

As per above, in for updates on your progress on this !

Cheers, Dennis!

[nsogiba]

Amazing! Keep the pics coming.

[e34Croak]

Neat Swap!

[Sir Montalbon]

Looking forward to this thread!

[wannaBMthree]

You sure it's a 94 540? Looks like a 95?

Probably built in 94' but a 95' model year like mine.

[Creesic]

Ohhhh.... I've always wanted to see more of these. Why is this such a rare combo?

[Timothy Prewitt]

Yeah, it's a late 1994. So the VIN tells me.

There aren't too many like this probably because of the expense to build. You can do an LS swap with much less money and have much better HP gains in the end.

[bimerok]

Great start. Looking forward to updates!

[Redfive]

Yeah, it's a late 1994. So the VIN tells me.

There aren't too many like this probably because of the expense to build. You can do an LS swap with much less money and have much better HP gains in the end.

Date of build doesn't equal model year. Mine was built 11/9/88, so it's an 89MY.

I ordered the delran bushings from ecs tuning and the first ones I got were oval.

I've been planning this swap for a long time. I just need someone to buy my turbo m30.

Keep the updates coming.

[Timothy Prewitt]

Mine was built 10/94 so the title says it's a 1994 BMW 540i.

They don't make Delrin bushings for the V8 6 speeds because the shift arm has a forked connection that makes it impossible to install without some modification. I searched around at multiple different places to find someone who made them but no one did, so I bought 2 sets for a 5 speed and modified them to fit. Did you find someone that makes them for a 6 speed Redfive?

Here is what I am talking about.



Verses the 5 speed

[Timothy Prewitt]

Couple things I left out, I am using a stock clutch and flywheel set up. The reason being that they came with the motor and had almost no miles on them. Contrary to popular belief dental students are not well to do. $400,000 of student debt makes me save money as often as I can. What makes this build possible is my amazing wife. We both are lucky enough to be working and going to school at the same hospital, (she is a NICU nurse at Loma Linda University Hospital) so we only needed one car. I sold my e46 M3 to make this project possible. We live off her income while I slave away in school. She really is amazing.



I did make one rookie mistake, I mounted the e34 6 speed thinking it was no different from the e39 420g. The e39 420g has a port for the crank position sensor whereas the e34 420g does not. I had to source a new transmission sadly. For shifter I am using a short throw from a Z3M. These shifters are shorter by moving the placement of the ball joint further up, which makes the linkage lower. There isn't much room to play with below the shifter in the e34 V8 unfortunately so the selector rod was hitting the Geibo, I customized my selector Rod a bit to fit. I'll take photos this weekend so you can see what exactly I did. I'm sure there are better options than what I did, but it worked out.



The vanos, chain guides, Rod bearings, and most of the sensors were all replaced/serviced on the motor before going in. I hope that this motor lasts me a good while yet. I'm not the best of mechanics, previous to this build the hardest thing I had done was an S52 OBD1 swap and 6 speed conversion in my e36 M3, so this swap is a slight step up in my learning experience. If I say something stupid during this write up its probably because I am not a mechanic, I'm a future dentist that likes building things, so hopefully I'm allowed a little leeway. I would never have gotten in to wrenching if not for this forum, so thank you to all of you.

[gpeterson]

Let me know if you need electronics to make your check engine light work for smog purposes - the CAN interfaces I make for S54 swaps should work with the S62 DME as well.

[Timothy Prewitt]

Let me know if you need electronics to make your check engine light work for smog purposes - the CAN interfaces I make for S54 swaps should work with the S62 DME as well.

Thanks! I will need it for sure.

[gpeterson]

Thanks! I will need it for sure.

Looks like you will need it for proper A/C as well - ETM shows the E34 A/C compressor driven by the DME as it is on E30/E36.

[Timothy Prewitt]

I was in Fresno for a bit and was able to take some pictures and finish the throttle install. Here is the difference between the throttle arms between e-throttle and cable.



Here is the arm installed with the potentiometer.





Here is what I did with the shifter linkage. It was hitting the Geibo so I flattened the center portion to give it clearance.



Here are some pictures just for fun. In a couple weeks o should have it running, I just need a weekend that I don't have to study on.

[burninator]

Awesome build! Can't wait to see how it turns out.

[ATXE30]

Great thread! I might end up doing this one day with me E34 M-Sport.

[ECSTuning]

[UnrulyGrace]

What a great build, looking forward to seeing more progress. On a side note, are you looking to sell the 420g originally from the e34?

[Timothy Prewitt]

Thanks everyone!

What a great build, looking forward to seeing more progress. On a side note, are you looking to sell the 420g originally from the e34?

I'm not sure what to do with it. I have an M60, M62TU and a 6 speed just sitting in my garage. I'm contemplating my options...

[UnrulyGrace]

Thanks everyone!



I'm not sure what to do with it. I have an M60, M62TU and a 6 speed just sitting in my garage. I'm contemplating my options...

Sounds like my garage minus the spare 420G. Only reason I ask is my car is closing in on 250k and it'd be major peace of mind to have a back incase mine decides to let go. Let me know if you want to part with it, and I'll be following your build closely.