Finally, M3 Engine Going into 525iT

It's been a long time coming. The engine and trans have been sitting in the shop for three months just waiting for the engine lifts, rack, and designated technician to become available at the same time. Got my 92 525 Touring in today and we have most of the accessories, intake, radiator, and exhaust off already. We'll drop the engine/trans/suspension as a unit from the bottom tomorrow. The replacement 96 50k mile M52 engine is already bolted to a fresh auto trans and sitting on the floor. Will be using the Touring's M50 exhaust, intake, accessories, and a 95 M3 DME w/Turner Performance chip w/EWS delete to make everything work. The engine harness is from a 94 525 w/vanos. I had to change a bunch of stuff going from an OBDII engine to a OBDI installation. Had to buy new crank sensor, cam sensor, knock sensors, vanos solenoid, valve cover, ignition coils to name just a few. The factory M52 parts had different plug ends that wouldn't work with the earlier harness. It will still look like a factory installation when done. Will take some pics and post once the inevitable bugs are worked out.

Paul L

S52.

I'm curious to see what you think of that motor in the 5. Mostly because of the extra weight compared to the M3, but intersesting non the less.

Sorry, but did you say AUTO trans??

Bummer... Would be heaps more fun with a manual...

I am really confused - you're running a '96 motor... which is an S52 on an S50 ecu? Also, the M3 and 325/525 harness do not pin-out correctly if my memory serves right.

K really confused: M52 bolted to an Auto trans? Thats a 2.8L motor... S52 mated to an auto trans? that's blasphemy.

It's a common swap and you will enjoy all of it! Share when you are done!

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Originally Posted by gtopaul

It's been a long time coming. The engine and trans have been sitting in the shop for three months just waiting for the engine lifts, rack, and designated technician to become available at the same time. Got my 92 525 Touring in today and we have most of the accessories, intake, radiator, and exhaust off already. We'll drop the engine/trans/suspension as a unit from the bottom tomorrow. The replacement 96 50k mile M52 engine is already bolted to a fresh auto trans and sitting on the floor. Will be using the Touring's M50 exhaust, intake, accessories, and a 95 M3 DME w/Turner Performance chip w/EWS delete to make everything work. The engine harness is from a 94 525 w/vanos. I had to change a bunch of stuff going from an OBDII engine to a OBDI installation. Had to buy new crank sensor, cam sensor, knock sensors, vanos solenoid, valve cover, ignition coils to name just a few. The factory M52 parts had different plug ends that wouldn't work with the earlier harness. It will still look like a factory installation when done. Will take some pics and post once the inevitable bugs are worked out.

Paul L

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Originally Posted by Scott H

It's a common swap and you will enjoy all of it! Share when you are done!

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Scott, the M50 vanos harness is not the same as an M3 harness... ask BJL4776 how he knows that :)

a chicago independent who knows more about swaps than you and any other resource you can find short of Brett Anderson.

Take a seat Jon, you don't know as much as you think.

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Originally Posted by Jon K

Scott, the M50 vanos harness is not the same as an M3 harness... ask BJL4776 how he knows that :)

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Quote:

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Originally Posted by Scott H

a chicago independent who knows more about swaps than you and any other resource you can find short of Brett Anderson.

Take a seat Jon, you don't know as much as you think.

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Of course it can be adapted - but it added much confusion to BJL4776's install. Giving him a heads up it won't plug and play. I stand.

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Originally Posted by s_ribbens

S52.

I'm curious to see what you think of that motor in the 5. Mostly because of the extra weight compared to the M3, but intersesting non the less.

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My 535i 5speed & supacharged m3 convertible both weigh very close to 3,400lbs on the same scale at a local transfer station. M3 manual gearboxes seem pricey & abused when available used, at least around the pacific northwest. The m3 drives like a much lighter car, thanks to the huffer, proper steering rack, & possibly the staggerred wheels.
If this conversion is being done within a budget, I could understand sticking with the autobox.

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Originally Posted by Martin in Bellevue

My 535i 5speed & supacharged m3 convertible both weigh very close to 3,400lbs on the same scale at a local transfer station. M3 manual gearboxes seem pricey & abused when available used, at least around the pacific northwest. The m3 drives like a much lighter car, thanks to the huffer, proper steering rack, & possibly the staggerred wheels.
If this conversion is being done within a budget, I could understand sticking with the autobox.

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I don't blame him using the auto as a friend up here has bought 2 transmissions for his OBDI converted S52, used but less than 70k miles from a local BMW yard and both failed in less than a month combined. You're right in that M3 manual trans seem to be abused when used - that or maybe its because they're typically pulled from wrecked cars and may be damaged.