M30B35 Engine for sale, complete, with all electronics

Wikipedia says:

IMAG5880The BMW M30 … is a straight-6 SOHC piston engine which was used over a 28 year lifespan over many BMW models. Ward’s have rated the M30 as one of the “Top Engines of the 20th Century”.

Perhaps you own an E23 7-series car (730i, 733i) with a tired engine. Perhaps you own an E32 750iL in great shape but the engine has failed.

You would LOVE to change to a well-running 3.5 liter M30 engine with the latest Bosch electronics. Your older BMW would have a new lease on life.

There is an undeniable cool factor, too. The newer Bosch engine electronics don’t just have the latest updates but they also look more high-tech. Imagine you open the hood of your 1970s or early-1980s BMW, to show a friend. Inside is something that is NOT period correct … ooh. Wow, what IS that?

Perhaps, on your car, the engine lacks power by now, or is smoking, or needs major work. Instead of repairing, maybe it makes sense to upgrade. The late-model M30 engine would give a tired car a new lease on life and you would enjoy “sheer driving pleasure” again.

In both of the above examples, the newer M30 is likely to bolt right in with minimal or no modification. Yay!

* * *

Let’s analyze the engine-swap process cynically. Imagine someone buys a newer M30 engine plus a basket of parts, and hooks it all up. Mechanically, it might be perfect. Electronically, something might well be wrong. And, the many possibilities don’t make this a simple problem. Your delight at the simplicity of the mechanical aspect might soon be overshadowed by the hassles of the plumbing or the electronics. Could be, something is missing, or broken, or hooked up wrong. It’s hard to diagnose.

Wouldn’t it be SO much nicer and simpler to have the new engine be accompanied by EVERYthing you need to start it and run it? Instead of buying an engine plus a basket of parts, you buy an engine that’s IN a car. You turn the ignition key and the engine starts. As you move the engine into the recipient car, you test-start it every now and then to make sure things are still OK. That way, if there is a problem, you know it’s in something you have JUST worked on.

IMAG5877You get to take pictures of the way things are before you move them, and you get every fastener that’s involved.

  • No more scratching your head or looking on the Web, figuring out what goes where.
  • No more driving around trying to buy the right fasteners or missing parts.
  • No more having to special-order little missing pieces that drive up project cost and delay your progress.

Everything you need is complete, and right there. Proof: when you buy the engine, it starts.

Starting says a lot, but it doesn’t say everything. You also get to have a professional BMW mechanic of your choice do a compression test and a leak-down test.

Why a professional? Because I don’t want the spark plug threads stripped by well-intentioned but overzealous amateur folks. Once you own the engine, you can work on it yourself as much as you like. Due to my approach: as a buyer, you can buy with the confidence that I didn’t let half the Western world’s amateurs mess with the engine you end up with.

The engine comes equipped for an automatic transmission and includes the torque converter. On automatics, the throttle position sensor is more complex, so if you plan to use this in a stick shift car you will want to swap out the throttle position sensor and related wiring, and you will want to replace the torque converter starter wheel with a regular flywheel, clutch, etc.

IMAG5748The M30 as used in the 1992 BMW 735i is a powerful beast. I have owned and driven this particular donor car for many years, including at impressive speeds that my lawyer would probably advise me to not disclose. That is why I am offering this engine with such a high degree of confidence.

The Bosch electronics presume a catalytic converter, though. And, I cannot legally sell the one that came with the engine. It’s against Federal law for me to sell used catalytic converter units. How do we solve the problem legally? I officially sell you the entire donor car including the catalytic converter. You remove what you need and give the remainder back to me.

IMAG4900One of my customers recently needed the SI board that was part of an E28 instrument panel. I didn’t want to remove and sell just this part, plus there’s value to the customer in seeing it work in context. So, I sent the customer the entire instrument panel. He removed the SI board, and sent back the remainder of the parts. This donor car premise works the same way. You also don’t have to insure or register the car because you’re not going to drive it.

Why am I selling this engine in this way? I used to have a magnificently-running E32 BMW 735i and then it got more and more body damage. Then, the transmission went out.

IMAG5747I have a replacement ZF 4HP-22 transmission all ready, and I can install it, but then I still have a 7-series car with a lot of body issues. The dent in the trunk is only one example. A dent in the roof is another example. The car might well be worth more as parts.


I have enjoyed its engine for many years, and took good care of it, so unless I’m missing something (that the tests would probably show), it’s a good, solid engine. I maintained it well, with the plan of keeping the car for many years. The previous owner took even better care of it.

I think this paradigm solves so many problems that I think this is a viable business model for my used-parts business, going forward. I plan to repeat this offer whenever next I come across such a situation again. However, to find a well-cared for engine as such from a seller / car that I know and trust … that is not all that common. And, this car is special because it’s one that I have personally owned and driven for several years.

* * *

How would this work?

  • You make arrangements with me, to buy the engine.
  • You put down a small good-faith deposit.
  • I keep the engine for you.
  • If you plan to buy the transmission too, you do the same for that.
  • Within the pre-agreed time-frame, you visit the car at my location in northern Nevada.
  • You start it and test it, and you have a professional BMW mechanic test it too if you like.
  • We apply the deposit.
  • You pay the balance the engine (and if you like, the transmission, too).
  • You also pay a refundable deposit for the rest of the car.
  • You take the car away, catalytic converter and all.
  • You work on the project.
  • You start to slowly separate the parts you need from the car, taking notes and pictures.
  • You start the engine every now and then to make sure it all still works.
  • Eventually, you have transferred everything you need.
  • Assuming it’s still in the agreed-upon window of time, you bring the car back to me (or you’re too far away, you choose to forfeit the deposit, and you donate what’s left of the car to a local junkyard).

This sale presumes that you get to help yourself to:

  • The complete engine itself
  • All the ancillaries on it such as the alternator and A/C compressor and water pump (which reminds me: the power steering pump leaks. I can throw in a better used unit)
  • All the ignition and fuel injection components including the fuel pump, fuel injection computer, and engine wiring harness.
  • Whatever else you can reasonably interpret to be in your favor as such, e.g., the radiator.

In other words, you are, by design, getting a very, very complete solution. All I expect back as to the rest of the car would be things (e.g., seats, doors, sunroof, trunk) that by no reasonable interpretation can be part of the engine or transmission or the parts that would make them work.

Do you like this approach? If yes, please contact me to discuss pricing. If you like omit the transmission, the price for the engine, and whatever it needs to work, is $1,800. If you add the transmission into the deal, the price increases by $600. The transmission is from a 1987 535i that I also personally drove.


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