E30 M30 SWAP writeup.

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ELECTRICAL
Assuming you meet the following conditions…
-You have an 88-91 E30 motronic 1.1, 1.2, or 1.3 All compatible
-You have an E32/E34 engine motronic 1.3

You have 2 options here…

1. If your E32 came from an automatic transmission car, then you might want to consider option 2. If not, then you will have fun wiring and bypassing the automatic transmission park. My E32 came from an automatic car. I tried fervently to wire it up, then gave up and simply went to option 2. If you must, then good luck. The E32 engine that I bought has 2 plugs. I tried to take the regular ECU from the M30 engine (ECU 0 261 200 179), and put slap it on. On the C-101 plug (by the fuse box on firewall), there is a round engine plug. Take the harness from my E32 engine and plug it directly in. That should send gauge signals and ignition stuff through. All in all, it should have been a direct plug-in. Unfortunately it wasn’t and I couldn’t figure out which wire went where. Take a look a what it looked like trying to find the automatic park:


2.Take the E30 engine wiring harness that you had when you removed the old engine and lay it across the M30 after the M30 is dropped in your car. Extend some wiring to meet certain sensors (they are in different positions than in the M20). Think about it. The harness is made for your car specifically. You can use the same M30 ECU that came with the engine (automatic or manual car, doesn’t matter). All of the sensors on your M20 will be exactly the same on the M30, just in a different place on the engine. Same crank sensor with same number of wires, oil pressure switch, oil level sender, coolant sender, temp sensor.. carbon canister…etc. Obviously the C101 port will match up fine because IT’S FROM THE SAME CAR. All of your gauges should work perfectly with no calibration needed. Think about it as your car not knowing that a different engine was even dropped in. I do not know if a 13 button OBC will work. I hooked up an analog clock, so didn’t bother with that stuff. I had a supereta, so needed a new tach plug and tachometer to meet the 7k.

Example of motronic 1.3 ECU connector. Note that it has 3 rows of pins. That is common on all E34 and E32 M30 engines as well as any E30 made after 1988.


If you have a different E30 or M30 than what was highlighted here, then please refer to this spreadsheet and it should guide you to the proper wiring technique for any combination of E30/M30 you might have. Thanks to www.r3vlimited.com Rs4pro3. He is so knowledgeable and created this table.

These are simply links to the infamous “Mitchell diagrams”. http://www.autolib.diakom.ru/CARS2/index.html. The engine compartment files are probably the most important, but I included the fuse box diagrams just in case you need to trace a wire all the way back. As another route you can take, there is another link to wiring diagrams just to double check yourself. These diagrams are more like the Bentley manual wiring diagrams. They are probably more helpful in many ways, but the files are very large.

http://wedophones.com/BMWManualsLead.htm

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ELECTRIC FAN
I have a stock E30 2 stage electric fan. It cools the engine “ok”, but I could definitely do better. I was thinking of getting an E32 fan due to the larger fan blade diameter.
These fans suck a lot of amperage! (16-20amps), but it’s worth it for the cooling that it does. You can have many setups, but I will highlight 2 options.

• The fan will run off of a low temp switch from the E28 535i radiator. The switch will be low temp switch and close at 82C. I got it from www.bavauto.com and here’s what you do. You run the switch inline with the fan and inline with the battery and have a fuse in the circuit for safety. Make sure it’s thick wiring, or the insulation will melt. I’m thinking 8 gauge is find. Like I said, it’s very high amperage ( I haven’t measured it).
• You can always forget the radiator switch and run a switch yourself to the fan. For this, I would use a relay. That way, you won’t have to worry about any melting or fires in the cabin where your switch is. Here is a diagram of how I wired for the switch. This way I can turn the fan on and off whenever I please. I have low amp line and the high amp line fused for safety.

Stock E30 fan Stock E32 fan


What if the fan itself isn’t enough? Well, maybe your fan isn’t installed close enough to the radiator itself to make a substantial difference. In this case, you need to make a shroud over the circumference of the fan. It will not prohibit air getting to the radiator, it will channel the air that is being blown by the fan to the radiator to ensure that all the air goes THROUGH the radiator. This makes the fan work a little harder, but it makes a huge difference in the operating temperature of your engine, especially in traffic.
I had a space between my cooling fan and the radiator. This was bad because when I turned the fan on , most of the air blew outwards instead of going through the radiator. This was ineffective approach and I thought how to get most if not all the air blown by the fan to actually go through the radiator. Well, a shroud makes this possible. You can make it out of sheetmetal, plastic sheet, or any other pliable waterproof material. Here are a couple of before and after pictures.

Here, Without a shroud, Because the radiator itself puts up air resistance, air flows to the area of least resistance, that is to the sides where it can leak out…

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COOLING
E28 stock radiator is slim enough to fit inside. Grind off 2 tabs that the original M20 radiator sat on as the E28 535i radiator still has to go down 4-5 inches. The top of the radiator will line up with two holes that should be present on the E30. You can grind down the tabs with the engine in or out of the car. It’s just a lot easier with it out.

View looking forward with engine removed. The tabs in the Red circles must be grinded down so it’s completely flush as if it was never there. The radiator will then sit on the shelf denoted by the blue arrows and depending on your lateral position, it will mount to the Green circled holes. The bottom of the radiator will still need to be secured to the subframe somehow. Be creative. The E30’s from 83-92 vary slightly with where and how many holes are present, so if you must drill to screw it in, then so be it. Picture thanks to Jared Squires.

Here are the hoses I used:
Upper radiator hose: E32 (heater core) OR E28 Hose (no heater core routing)
Lower radiator hose: E28


Upper radiator hose is part 1. As you can see it has a little hose coming out of it…. This smaller hose going to the heater core will need to be cut and re-positioned in order to mate with the E30 heater core inlet/outlet pipes at the firewall. Some E28 versions do not have this extra hose. You might have to make a tee or go without heat. Lower radiator hose is part 2. Pretty straightforward and cheap to buy or find. I suggest buying it for $13.

Other heater core hose: E30 (needed to modify to tee back to the heater core as well). This is part 13 in the diagram). It’s a 3 way hose (all same diameter) and goes to the following 3 places.

• • Coolant tank reservoir
  • Heater inlet/outlet (doesn’t matter)
  • Thermostat housing

Coolant reservoir: Keep your E30 ’88-91 reservior (pictured above). It’s perfect and should remain in the same spot to function correctly (above the driver wheelwell).

For part 13 in the above diagram or Part 1 (small hose end) of the other diagram, you can use a brass fitting (barbed nipple) to connect hoses to make virtually whatever you want. The barbed connector you want is part number 32-097 from www.fittings4less.com. It’s a barbed brass mender. If you run out of hose, you can always go to autozone or whatever to pick yourself up some 5/8” coolant hose.
Here is a pic of the 5/8” coolant hose being routed in between the manifold and brake booster. It could be a possible culprit for an air bubble , so be careful as you bleed.


Again, I used the following website MANY times for all fittings I needed for the various jobs on my conversion You can get the brass fittings to tee any size line at the following website:
www.fittings4less.com. This website has ANYTHING you need to rig fuel lines, coolant lines, high pressure, low pressure. They have a wide selection and customer service is great.

Bleeding the system:
Bleeding the system is a bitch… ask anybody who has an M30 in an E30. Overheating is a constant issue if not dealt with properly. There are many techniques used to bleed the system. This depends on whether or not you have a heater core for heat. I do have a heater core, so the plumbing is a bit more complicated. You need to be very careful about air bubbles in the system. This is because when the engine gets hot, the air will expand and possibly explode your hoses and leave you stranded.
I finally got my temperature at a little bit past the ¼ mark when driving and right at the ½ mark when in traffic with the electric fan on. This is good enough for me. On a really hot day in standing traffic, the temp goes past ½ mark, then once I start moving, it slowly goes back to where it’s supposed to. Here are a couple techniques I used to bleed the system.

• • do it with the engine running, so the coolant pump can move the coolant around as you pump it. Do it when the engine’s cold so by the time the engine starts getting up to temp, you will have filled it already.
  • Hold the coolant reservoir physically as high as possible. I mean like 2 feet higher than the engine. You might want to have a friend hold it up for you as you pour the 50/50 mix into the tank. When you’re done, screw the cap on (when it’s still in the air), then install it in the engine.
  • Pour slowly! Let the mixture get into the actual engine and level off. If you pour too fast, you could create air bubbles trapped.
  • Last but not least, try to have the car at a steep upward angle so that the front of the car is at a really high, steep angle. Jack up the front of the car, park on a hill, whatever. Doing this will force the air frontward and upward toward the bleed screw.

Try to test this after you think you’re done by letting the engine sitting for about an hour after you bleed. Squeeze the upper radiator hose. You shouldn’t hear any air going through the system and it should be pure coolant filling the reservior every time you squeeze. That is a good sign that you properly bled the system.
You can check to see if the heater core is working by obviously turning on the heat. If you have air in the system, it could be trapped there and the heat simply won’t be that hot. It should be really hot when you turn it on.

For the coolant sensor installed on the engine, please use the M20 sensor. You can either remove it from your M20 engine or buy a new one. For compatibility reasons, the M20 temperature sender must be used.

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EXHAUST
Remember to please observe the laws in your state. Whether or not you need a catalytic converter in the line. I also got a ticket once like 4 years ago because the exhaust on my 325es was too loud and had to get a cheapo quiet muffler installed.

I’m letting you have fun with this. I was told that the front exhaust manifold needs to be from an E23 car in order to clear the motor mount bracket. If you go this route, you will also need the downpipes from the same car. For some reason, the exhaust headers from the E28,E23, E24 are DIFFERENT than the headers from the E32, e34. They have 3 bolts that hook up to the headers instead of 2. They are not compatible, so whichever exhaust manifolds you get, get the same downpipes. On another note. I tried to buy the downpipes used, but nobody sells them for insurance or safety reasons. Can’t sell used exhaust parts. At least in NY, but if there will be custom work done on it anyway, I don’t think it matters that much. Before I turbo’d my car, I had the shop guy press lines up to the downpipes and attach them to the headers with a couple exhaust flanges. He welded the two together and brought it to one 2.5” line, through a free flow cat, and out to a magnaflow muffler, which is very throaty, not raspy.

-Since then, I got my turbo on, which completely changed the exhaust system. The exhaust manifold was different and the kit I got from www.turbochargingdynamics.com had a 3” downpipe included, so it was easy to just weld a pipe right from that.

Note: if you let off the gas when coasting your car, and you hear backfiring, then more than likely you have an exhaust leak somewhere. Probably closer to the engine. When it sucks fresh air in when you let of the pedal, it backfires.

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STEERING PUMP/LINES/RACK
Here’s the problem I had with the power steering on my swap. I got the E32 735i engine. The 735i had what was called suspension stabilization. This meant that the steering pump actually controlled the suspension ride height and what not. The bottom line. It was not compatible with hooking up 2 simple lines to it. There was actually a third hole, which I believe controlled the suspension. What’s important is that I realized that the steering pump that came with the M30 was not compatible, so I had to buy an E28 steering pump and was lucky because all the bracketry was included. I was lucky and found it on ebay. For like $40. It’s possible to find any e28 at a junkyard and take out the bolts (I believe the high and low pressure lines are 17 and 19mm respectively)

The Steering motor that is checked is the one you should use. As you can see in the first picture, there are 3 holes for lines to go. I tried hooking it up and plugging in one hole. DOESN’T WORK. It just sprays it everywhere. The pressure’s too high. Use the correct steering pump. The Banjo bolts are 17 and 19mm, so you can’t mess up which one is the high and low pressure lines.

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OIL PAN/PUMP/COOLER
If you choose the E32 or E34 engine, then nothing needs to be done with the oil pan except changing the pan gasket while the engine is out. Other than that, it will be a tight clearance to the steering rack/subframe, but should fit nonetheless.

For those of you that choose E28, E23, or E24 M30 engines, the writeup simply calls to go to a junkyard, find an E32 or E34 oil pan AND pump and simply swap them out. That way you will be able to place the engine lower in the engine bay and not have clearance problems with your hood. Many E32/E34 M30’s didn’t even have an oil cooler. This simplifies the swap a lot too. Now you don’t have to deal with oil cooler line routing and mounting the oil cooler. I have not had a problem on my turbo application at all without the oil cooler. I wouldn’t doubt that it would be a good idea, maybe in the future.

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DRIVESHAFT
There are so many options for the driveshaft. Some people say to take the front half of E28 and rear half of E30 together, so it can handle the torque. www.e30.de says to use the M3 E30 driveshaft… mainly because it has the bigger guibo. Refer to “transmission” section for more detail about guibo and driveshaft size. Heres what I did. I went on www.wholesaleimportparts.com and bought a refurbished/rebalanced driveshaft for my ’88 bmw 325 supereta. The part number was 20680. It matched the bigger guibo (3.12”) perfectly. The part is $325 with an addl. $60 core deposit. Comes with a brand new center bearing installed already! When you get the driveshaft, you just send back the old one in the same box, free shipping back… you get your $60 back within 2 weeks credited to your card. They are a great company. So here’s what I did: I used the driveshaft that they gave me and installed it. With my 2 ½ engine position, the driveshaft had plenty of spline to match up, not to mention I still gave my center bearing that preload it needed as per the Bentley manual.

I have not had any problems with the driveshaft since. It is perfectly balanced up to 145mph and can handle up to 300rwtq and probably more, even on a hot day.

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FUEL
Looking from the driver’s side of the car the M30 fuel send line is on the right (red tape) and the return is on the left.

You can use the stock E30 fuel pump (unless it needs replacing), even good for turbo applications.
I also think it’s a good time to replace the fuel filter as well.
I used 19# bosch design III injectors. It’s not difficult to replace.

Because I have a turbo, I added a fuel pressure gauge. It goes in the fuel send line right before it hits the fuel rail. Check out the picture and you can see if you want to do this. If you plan on upgrading the car for tuning capability, no better time than now to put it in the line. I just put a tee in the fuel send line and routed it to a fuel pressure gauge (0-100psi). See picture below.

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CLUTCH/FLYWHEEL
Using the factory E28 Sach’s clutch kit is fine. It should hold up to 250RWHP, but will start slipping at the highway speeds if you downshift and then floor it, for example, should you turbo. You can upgrade to a high performance organic clutch for about $409 including pressure plate, bearing, and clutch w/ tool from www.turbochargingdynamics.com. It should be a direct bolt on to the flywheel. You can use the E30 Slave cylinder on the Getrag 260/5-speed or use the slave cylinder for E28 tranny. It does not matter. Please torque to the specs highlighted in the Bentley manual for the E28 BMW’s. I would put the clutch and flywheel on during your M30 maintenance. You may have problems keeping the crank from spinning as you are loosening/tightening the flywheel bolts. In that case, I guess be creative and find someone to counter the force, or you can use a powerful impact gun. That’s what I did and it worked fine for removal AND installation of the new flywheel. Here’s what I did

E28 Transmission from ebay… w/ E30 tranny bracket (kept from my E30)
E34 M5 Performance organic clutch kit www.turbochargingdynamics.com
E28 535i 11.5# lightweight flywheel www.JBRacing.com
E30 clutch slave cylinder. Hooked right up to the E28 tranny and it feels great.

I hear about compatibility that you can use the any E23,E24, E28, E34, E32, M5 clutch/pressure plate combination and it will work fine. The tranny will still bolt right up to it and the stock E30 slave cylinder will still work fine.

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TRANSMISSION
Use a factory E28 Transmission 5 speed as the flywheel/clutch that I bought is made for that specific transmission. The stock E30 tranny cross member is a perfect fit to hold the E28 tranny and should perform as a check for a square fit within the transmission bay in the car. I hear you can upgrate the tranny mount to the E30 M3 mount, but I don’t really think it’s necessary. Like I said, my car has 310hp and I haven’t had a problem yet. Unless of course you plan on tracking the car and really push it to the limits. If you get a transmission from an older E23,E24, or E28, remember that you will have the old electrical systems from those cars, so you will see the two spots for the reference and crank sensors on the flywheel area at the bell housing. You can still use this transmission anyway as the bell housing bolts WILL match up, but you can just ignore the spots for the sensors. They will not be used. Plug them up or leave them, doesn’t matter.
Your transmission will have the rear ouput shaft with the tri-prong holes appx 3.12” apart. THIS IS THE DIMENSION FOR THE BIGGER GUIBO that everyone talks about. The smaller guibo measures 2.6” apart for the tri-holes. That’s mainly found in 325i’s. This will play a big role in driveshaft selection when the time comes, so please read carefully.

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ENGINE POSITIONS /MOTOR MOUNT BRACKETS
Depending on the engine positions you choose, you can position the engine however you want. Like I said, I highly recommend the www.e30.de brackets from Tino. They are well worth the money. They are constructed with quality materials and the welds are really strong. I have been running them in my Turbo M30 for about a year now and have not had any problems! I used the type II brackets as pictured below:

Supplied 2 motor mount brackets custom from Germany. If you look at the picture on the top, there are 2 holes to mount to the urethane mounts. The hole that is circled is the hole position that would hold the engine further forward. In this position, the ignition distributor is actually pushing up against the E28 radiator. Not recommended on many levels, but if you must, then know that it is at least possible to do so. This way, there will be minimal firewall modification, and the driveshaft would either need to be “stretched” in order to fit, or you can always lengthen it. If you need to lengthen a driveshaft, then know that it’s a pain in the ass to do so. It’s expensive, and not worth the work and money when you can just move the engine back another half inch by doing what I did. What did I do? Actually, I drilled a hole right in between the two holes there and made a position 2 ½. No, it doesn’t compromise it’s strength. I actually have about ½” clearance from the distributor to the radiator. I’m compromising 50/50 weight distribution by not going all the way back, but it’s not going to make that much of a difference.

I have BMW E30 poly-urethane motor and hard rubber BMW E30 transmission mounts that are highly recommended. This eliminates a lot of the engine/tranny movement and gives you a more solid feeling when driving. Downside is it gives you a little bit more vibration transfer, but it’s really neglible. The Urethane mounts I purchased FOR AN E30 325I from www.bimmerworld.com for like $70, as well as the tranny mounts for $29. Bimmerworld takes a year and a day to ship though, so be aware.

Note: when dropping in engine, Put the engine in FIRST (with tranny attached), then put the radiator in.
Here are a couple pictures of my setup. I had my passenger motor mount bracket modified by Sweeny at www.turbochargingdynamics.com.

Passenger side Driver side

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CLEARANCES
Clearances to the left and right will be fine. Watch out for the oil pan, the radiator and the hood.
If you use the motor mount brackets from www.e30.de (I highly recommend them!), then you can position the engine forward/rearward however you please. I recommend the further back the better. The E30.de mounts accompany 2 positions, but I modified it to my liking anyway.
Don’t worry about clearances of the transmission. Worry more about the clearance you’ll have at the back of the valve cover on the engine itself. I also hear that if you have an older E23,E24, E28 engine, you will have to deal with the rear of the valve cover having a hose for head cooling. Another great reason NOT to use this engine, unless of course you get it for free J. Here is a picture of my car in the 2 ½ position. I’ll explain more in the next section. This is how my placement looks at the radiator.

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Cost excel spreadsheet available upon request

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OVERALL PROJECT COSTS
The following spreadsheet is as objective as I could get with allocating money to this project. Please don’t take it as “the word”. You don’t have to get any of the extra shit I got for mine, but it’s definitely an option if you can afford it. I got a lot of prices from www.bmaparts.com and www.bavauto.com. I used ebay for a lot of random parts like the tranny, electric fan, intake, hoses. Junkyards are your friend here too. You can easily shave off hundreds by doing bargain shopping…A lot of the fabrication prices are estimated as are the engines and motors. If you can find it for cheaper, good for you. You may get lucky.
Note: I was on the conservative side with some of my estimates.





# Engine assumed to come with the following: all accessories, belts, wiring, sensors, ECU, NO tranny, includes hipping
##Make your own brackets. If you can weld, this is where you can easily succeed. If not, buy from www.e30.de for $300.
###You can go to a junkyard and modify one yourself for cheap or a custom shift linkage built for you, which could cost a lot.
*E32/E34 M30 with '88-91 E30 cost: $0-$20 extra wire/solder..etc for misc wiring.
** These wires are for the E32 Engine with the pulse sensor wire. The E28 wires will suffice, but will not be as efficient
***Use E30 ignition coil
^Depends on what differential came with your E30 and which you choose to run.

Note: Driveshaft: $325+$60 deposit for refurb. www.wholesaleimportparts.com. Go to the driveshaft store on the website main menu.

Just spoke to Tino Treumer from www.e30.de. As of 7-2-2007, he still ships to USA without problem. Don’t be wary of the overseas transaction. I did it and it was at my door 3 weeks later. Tino is a very honest guy to work with. I got lucky and my engine had all wiring and accessories w/ ECU. Engine had 127k on it and I have pushed it to the limits and then some. I got a really great engine, so I think I paid good money for it ($1200 shipped)

There are many different ways to efficiently shop for all the parts you need. I’d have to say that after adding up all the numbers about the details with every aspect of the project, I put about $2500 including engine/tranny/driveshaft/radiator and A LOT of random parts such as hardware, hoses, battery, transportation costs. NOT INCLUDING EXHAUST. Exhaust was a whole different story.

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PREVENTATIVE M30 MAINTENANCE

This is what I bought for my M30 while the engine was out (purchased from www.bavauto.com).
Accessory Belts
Oil pan gasket
Rear engine seal*
Valve cover gasket
Distributor cap/rotor
Spark plugs/wires
Clutch/flywheel
I cleaned it all up. Painted the intake manifold and valve cover bla bla bla. I would not worry about the Timing chain. They should last the life of the engine. If you wish, you could purchase a timing chain spring and tensioner. The tensioner located in front of the forward most exhaust manifold and I believe is connected by a 19 or 22mm bolt.

If you would like to upgrade, you can get 19# bosch design type III injectors, High-torque clutch and lightweight flywheel. I do not recommend the Bosch platinum 4 spark plugs. It’s a dumb ploy to make you think you’re actually going to get a more efficient spark. The reality is that if you’re running on the rich side, it’s more consequential because the plugs gum up faster.

Remove the M30 clutch fan. As much as you may need it for supplemental cooling, it won’t fit unless you position the M30 really rearward. For the most part, it won’t fit in the engine compartment unless you chop a huge amount away from the firewall.

*Funny story, the first time I installed the rear seal, I didn’t knock the seal in the housing enough. So I drove the car around for about a hundred miles and it was leaking at the tranny/engine area, so I’m like, It’s gotta be the rear engine seal. So I removed the engine/tranny again, took it out of the car and inspected it. I had to get a new seal and a new oil pan gasket. After re-installing a new one, I realized that I did install it correctly. The problem was that when I put the grease on the clutch assembly for the throwout bearing, It liquefied after it got hot from driving and leaked. It wasn’t the engine oil at all. About 3 weeks of work to fix it for nothing!