The last day before the heart transplant.
This weekend the project to swap a low-mileage m20 motor into my e30 will begin. The last box of parts has arrived: these will replace the wear and tear parts on the donor motor before install.
My current motor has been well maintained since I got it – in fact most of the same parts were replaced on it less than a year ago – but the clutch is slipping and it’s burning oil. This is the time to retire it.
Rear Main Seal
78 mm Guibo
Victor Reinz Top End Gasket Set
Exhaust Manifold Gaskets
Pressure Plate Bolts
Satch Clutch Kit
Exhaust Manifold Gasket
Hex Nut M10
Power Steering Belt
Cover Plate for Felt Ring
Cover Plate for Back of Pilot Bearing
Engine Block Gasket Set
I also got something special for the car, made in Italy. I’ll post a photo once it’s installed on the car in about a week.
On Saturday I borrowed an engine hoist from local e30 maven Eric Berger, put it in a rental truck and drove up to Walnut Creek to pull a donor M20 for my car. Though Bernz (owner of the donor motor) and her neighbor Dillan are pretty experienced with motor removal it took 5 hours, lots of spilled engine fluids and a few mistakes to get it out of the car.
The donor motor has 75,382 miles on it and I’m looking forward to putting another 150,000 miles on it myself. The motor will get a complete inspection, all the wear and tear parts will be replaced (except the head gasket) and then it will be installed in my car. My car will probably be off the road for 2 weeks to facilitate the swap and maintenance.
AFM and airbox removed.
Finally removing the engine.
Engine almost removed.
Dillan removing automatic transmission.
Strapped in for the trip back to home.
M20 Motor Removal Checklist
- 2x Heater inlet/outlet hoses at the firewall. Flat head screwdriver for the clamps.
- 2x fuel lines, the feed and return, 1 at either end of the fuel rail. Flat head screwdriver for the clamps.
- 2x engine mounts, 1 each side. 16mm / 17mm bolt.
- Engine ground to oil pan. 13mm bolt.
- Radiator. 2x 10mm bolts holding the top support bracket.
- Radiator hoses to radiator. Just more flat headed clamps.
- Brake booster hoses. Flat headed screws.
- Exhaust down pipes. 17mm 16mm bolts. You can drop and remove the exhaust if you like, but you have got room in some cases.
- Intake boot, air box. More flat head screws, 10mm bolts for the air box.
- Driveshaft, 3x 17mm bolts with 17mm nuts.
- Shifter linkage. 13mm bolts various sizes in places.
- Wiring loom, just unplug from the ECU and toss it over the engine, unbolt the harness ground to chassis, usually somewhere by the strut tower.
- Power cable to the Starter motor. Just disconnect from the back of the starter motor and leave it in the car.
- Remove gearbox X-member. 13mm bolts.
M20 Motor Removal Walkthrough
- Let the car run in the park position if you have an automatic or let it run in the N position if you have 5 speed while you pull fuse 11 to empty all fuel from the system. Make sure you have your E brake on if you have a 5 speed. When the car shuts off turn your key to the off position.
- Go to your trunk and unhook your battery. You will need a 13mm wrench. Unhook the (-) side of the battery first then continue to the (+) side.
- Once they are unhooked pull them off and push them to the side. This is what you should have.
- Then go to your glove box to unhook your ECU.
- Open it up and here is the ECU plug. You will want to pull this silver clip back and unhook the ECU.
- Now go out to the engine bay and unhook all of the power wires from the distribution block on the firewall. You will need a 10mm wrench.
- Then unhook the ground wire from the strut tower. Also a 10mm.
- Now pull the plug for the ECU through the firewall.
- Next you can unhook the coil. pull the plug wire and boot off the top and you will see two wires. You will need a 8mm socket and a 10mm socket.
- Now go to the driver side of the car and unhook the MAF.
- Then take a flat head screw driver and loosen the clamp that holds the boot onto the MAF and take it out. You will need a 10mm wrench to loosen the two bolts on the side of the air box.
- Now its time to unhook the rad. You will need a bucket to catch your coolant. We have a drian in our floor that goes to a holding tank so we didnt need one.
- First take the hose off the bottom of the rad on the driver side. you will need a flat head screwdriver.
- Then unhook the hose on the passenger side.
- While your over there unhook the coolant sensor on the side of the rad.
- Now unhook the top hose.
- Now its time to take the radiator bracket off. You will need a 10mm wrench.
- Now pull your radiator out and put it to the side so you wont poke any holes in it.
- Now go back over to the driver side and unhook your throttle cable. You will need a 10mm.
- Then pull the throttle back and unhook your cable and pull it out.
- Now its time to unhook the c101 plug. This is located next to the fuse box and it just untwist.
- Now you can get down in and unhook your hoses for your heater core. You will need a flat head for this also.
- Now you can unhook the vac hoses from the brake booster to the TB. These just slide out with a little wiggle.
- Now its time to unhook your fuel lines. First one up is the one on the FPR. Be careful when you do this so it doesnt get in your eyes.
- Now do the one on the fuel rail, be very carful on this on since it will have more pressure in it then the first one.
- Now unhook your plug and hose from your evap can. This is located under the throttle body.
- Now unhook the ground straps from the oil pan to the frame. You will need a 13mm for this.
- It may help to jack up the front end of the car slighly higher to make removing the engine easier.
The e30’s clutch is starting to slip so it’s only a matter of time and miles before it falls out on the road and leaves me stranded. This would be the time to do a s52 engine swap but I’ve decided to buy a low-mileage donor m20 and have a clutch kit installed.
I have no logical explanation for reversing my decision: there was absolutely none, zero doubt in my mind that a s52 engine swap was the right thing to do up until three weeks ago. Something happened: I got sentimental. The pros and cons that I fabricated to pacify the logical side of my brain follow but ultimately this is an emotional decision. I like the m20. It seems like the right motor for me and the car: it’s modest, dignified and adequate.
I expect to pick up the new motor this weekend.
Above: A clean example of the BMW M20 engine.
Pros of Staying M20
- I’ll save about $6000 on parts and labor by sticking with the M20 motor. This is not my primary motivation but cash is always a consideration. The car needs so much more work: racing seats, dents pulled, paint, steering rack. There’s no shortage of other places to spend money besides the engine.
- The m20 will not win any drag races but it has plenty of power especially in gears 2 and 3. To be completely honest it’s already more car than I can handle (as I learned at the last Car Control Clinic) and once my abilities match those of the car I can reconsider the swap.
- The m20 is a great learner motor and I have everything yet to learn. It has fuel injection, modern fuel management, a computer and is easy to repair with minimal equipment. Anything newer will just be more complicated and harder to maintain for a novice like myself.
- I could learn a lot doing an engine rebuild myself (someday). Once I’ve mastered that, learned all I can about m20s and enjoyed the results I could do the s52 swap and become an expert in that too. This appeals to me more than just paying someone else to do it now and learning little from it – one of my primary motivations in buying this car to begin with was to learn about cars.
- The m20 looks like a motor. Perhaps this is the worst reason to choose an engine but I’m a visual person and I like the way the m20 looks. There’s wires, hoses and lots of moving parts. On the s52 everything is covered up.
Above: s52 motor in an e30.
Pros of Going S52
- Win drag races.
- Ungodly amounts of power and acceleration.
- Sounds like a wild animal!
- There are other engines I like better than the s52. Like the s54 which I find to be an attractive looking motor that’s relatively servicable. If I wait then I may be able to afford that motor some day.
- Waiting gives me a chance to get a place with my own garage and not only learn about the m20 but take on a new project car – perhaps even a dedicated track car.
Above: s54 motor in an e30.
To be continued…
At 4:30 or 5:00AM you can usually find me either driving one of Silicon Valley’s twisty mountain roads or at my desk collecting my thoughts and making notes. By 5:30AM I’m at the gym and by 7:30 I’m at my desk eating breakfast and going over my todo list or email. I even get up early on the weekends. I say that I’m a “morning person” but I probably have terminal insomnia.
I don’t drink coffee because it elevates my blood pressure: I get through the day on attitude. I was definitely a darkling when I was a kid but this plate isn’t about that. It’s about announcing morning’s arrival in my noisy little e30 and taking life’s wheel.
I’ve got an appointment, stand by for photos of the new plates on my car in about a week’s time.
Update: Couldn’t make my DMV appointment, postponed pickup for a week.
Eleven e30s at this month’s BMW Club Cars & Coffee (Santa Clara).