Need advice e30 m5x swap

[tacollama13]

I recently bought an automatic 1988 325i Cabrio and I was excited to get to giving it some TLC, sadly after taking it into a shop for an inspection and compression test I found out that my m20 is basically a goner. I don't have the necessary skills or tools to fix/rebuild it myself and the cost to repair is looking like >$15k. With this in mind I got this idea of just taking the old engine out and swapping a m5x in. My thought is the cost will likely be higher than if I were to repair but the eventual result could be amazing.

I have been thinking both about an m50 or m52 swap and am having difficulties deciding on which one would be the most suitable. I anticipate this costing a significant amount and am not afraid to pony what I will need to make this swap happen. I don't want to sacrifice quality for cost, but money is an object.

My main issue is I have little to no experience in working on cars. I have been trying to do my due diligence in researching the swap to the best of my abilities but I would love to get any and all types of advice from anyone who has experience with these engine swaps. I am starting to get mind numbed and lost in the pages of forum and wiki postings so I would greatly appreciate any help or even a point in the right direction!

[moatilliatta]

If you don't have the mechanical aptitude to rebuild an engine, A swap is going to be hard also. But only because you haven't, doesn't mean you can't. Any E30 is going to need work, you could sell what you have for something with a good engine and start with the smaller jobs and learn the ropes. Most project cars never get finish, it would be terrible to add to that statistic.

[82eye]

agree with moatilliatta

$9k sounds seriously heavy for an m20 rebuild. for that i could rebuild the m20, do suspension, and maybe a couple other things as well. i would suggest you use some money to tool up, get the basic machine work done, and put it together yourself. it's a perfect opportunity to learn how to wrench. the m20 is a very basic engine to learn on, if you can't understand how they work you won't stand a chance on a m5x.

edit : if you go the m5x route you'll probably burn through more than the $9k if doing it all at a shop. these days everyone skips the m5x swap for s5x. it's the same amount of wrenching pain for a much better result. the s5x will be considerably more expensive to source though.

[TobyB]

Do you have the equivalent of a 2 car garage to work in?

If not, I hate to be that guy, but you need space to do a swap...

your best bet, if you want to learn, is to start by finding a used M20, and just doing a 1:1 engine change.
If that seems fun and easy (after it's done, of course) THEN maybe start looking for an M54B30.

t

[tacollama13]

I've been reading the replies here and on other forums and am looking into the m52tub28 , it seems like my existing zf 4hp22 wouldnt be a great match for it due to the electronics, I've been eyeing a zf 5hp19 with the idea of pulling both engine and trans out of a 528i donor but I can't seem to tell if all m52tus are aluminum or just the z3.
Also I'm hesitant to do a manual swap as I plan on using this as a daily driver and don't actually know how to drive standard yet. The track e30 is a dream i do have tho, s5x and manual would be great but i wanna do that on a hard top

[Panici]

I have to ask, what specifically makes your existing engine a "goner"?
Did the shop give you per-cylinder compression numbers? Did these numbers come up with a "wet" test when they add oil and test again?


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If you have little to no experience working on cars, it's going to be a STEEP learning curve doing anything with an engine removal.
This includes a rebuild of the original or a swap to something newer.

I'm not trying to dissuade you, but rather give you a realistic picture of what's involved.

You may be better off starting with a runner that just needs a mechanical refresh. Brakes/suspension/fuel system/etc.
After you've gone through refreshing everything you will have a bunch of skills that will make pulling an engine more realistic.

[tacollama13]

From the compression test I was told "After performing compression test, found cylinders 5 and 6 are operating low at 123psi and 103psi, subsequent leakdown test revealed 42% and 75% leakage mostly at piston rings", also a note about the head gasket leaking oil on the exhaust side, oil pan leaks and drainplug threading issues. They wanted to do a full disassemble of the engine as well as replacing oil pan and resealing cylinder heads

[e30davie]

Advice? Be good to your mother.

[DesertBMW]

you don't have the skills to fix M20 engine but you do have a skill to do M50 swap into it? First bad idea was buying 1988 Convertible automatic.

[Panici]

you don't have the skills to fix M20 engine but you do have a skill to do M50 swap into it? First bad idea was buying 1988 Convertible automatic.

Hey, automatic verts make great parts cars!

[tacollama13]

you don't have the skills to fix M20 engine but you do have a skill to do M50 swap into it? First bad idea was buying 1988 Convertible automatic.

Thanks!

[tacollama13]

Also I don't need people telling me im f#$%ed or should just do something completely different, if you're not gonna at least attempt to give me some info or help then just dont reply lmao

[DesertBMW]

Also I don't need people telling me im f#$%ed or should just do something completely different, if you're not gonna at least attempt to give me some info or help then just dont reply lmao

You admitted you don't know how to work on cars but you want to do a swap. We already helped you with advise. Your post looks like it is a troll post, you just joined the forum and talking crazy

[82eye]

if you're gonna stick to an auto the swap is not worth the cost. it will actually cost more than a regular swap. you'll have zero choice but to swap in a matching trans, and then a possible custom driveshaft etc. there really is nothing for info on an engine swap retaining an auto trans that i've seen. you can search the forum, but i don't recall anyone bothering.

rebuilding the original or swapping in a known good m20 are your very best options for the current driving goals you have for the car.

[tacollama13]

You admitted you don't know how to work on cars but you want to do a swap. We already helped you with advise. Your post looks like it is a troll post, you just joined the forum and talking crazy

well sorry to disappoint but I am serious, I'm not planning on doing this swap for at least 10 months and I'm trying to learn as much as I can while I don't yet have direct access to any of the materials I've been watching many a video and reading many a guide/forum post but I am having some confusion and am just asking for info and help.

The kind of attitude you're giving me really seems to only push people away from using forums like these and makes you seem like a prick who cares more about checking somebody's shop cred than giving constructive advice. Even calling "you don't have the skills to fix M20 engine but you do have a skill to do M50 swap into it? First bad idea was buying 1988 Convertible automatic." advice is charitable, you could've at least provided some reasoning or direction for me to go in, instead you just pop in and spout off some unhelpful jab. I honestly was excited to learn about cars and get my hands dirty but if you're an example of the people I have to learn from then I might have to reconsider.