Z3 bad engine block

[cjames10]

I took a gamble on a Z3 2.8, it was smoking and overheating. So I opened the engine to find everything is in good shape except the previous owner put in Bigserts and they pulled. I need a new engine block. I think I have three options and hopefully someone here can help.

1. Find another Z3 2.8 M52B28 aluminum engine, which sounds either expensive or hard to find.
2. Use the M52TUB28 block out of a 1999 328i or 528i. Will this work? Is the M52B28 aluminum engine block the same as the M52TUB28 aluminum block?
3. Use the M52B28 cast iron block(or entire engine) out of a 1996-1998 328i or 528i.

The car is beautiful, new tires original rims near perfect interior. The exterior trim is perfect. I just need to get the motor running.

Any help would be appreciated.

[zellamay]

I'm not sure whether you are asking this, but I would definitely buy a complete engine, rather than a block. Also, I'd consider an S52. Bolt in, lots more power. Physically outside, they are the same, in fact many parts interchange. I'm not the expert, just read about it, but apparently all you need is engine and ecu, and maybe a power steering pump. Here's a thread about it: https://www.bimmerfest.com/forums/sh...d.php?t=784354

[Tigershark48]

Good oportunity for an LS-1 swap. ;-)

[Tim95M3]

The block and rotating assembly between the aluminum M52B28 and M52TUB28 are the same. I'd also suggest a complete motor rather than block swap. S52 or any other iron block is an interesting option, but unless you're planning for boost, no need for the extra weight. I'd just try to find another TU myself.

[Muzz258]

The block and rotating assembly between the aluminum M52B28 and M52TUB28 are the same.

Sorry but this is incorrect. The M52TUB28 is a twin VANOS engine and the water flow through the block and head is the reverse of the single VANOS M52B28. You can not use the M52TUB28 block with a M52B28 head.

Go for a complete engine swap. A M52B28 is the easiest. If you go for a M52TUB28, then also get the DME and engine loom. You will need to learn how to align the new DME with the EWS to get the engine started

[rf900rkw]

The block and rotating assembly between the aluminum M52B28 and M52TUB28 are the same. I'd also suggest a complete motor rather than block swap. S52 or any other iron block is an interesting option, but unless you're planning for boost, no need for the extra weight. I'd just try to find another TU myself.

Not true. The cooling system operation, flow, and water jackets are very different. You can not put a M52 head on a TU block, nor a TU head on a M52 block.

[Tim95M3]

Sorry but this is incorrect. The M52TUB28 is a twin VANOS engine and the water flow through the block and head is the reverse of the single VANOS M52B28. You can not use the M52TUB28 block with a M52B28 head.

Go for a complete engine swap. A M52B28 is the easiest. If you go for a M52TUB28, then also get the DME and engine loom. You will need to learn how to align the new DME with the EWS to get the engine started

I stand corrected. Did not know this. I also read this as a bad M52TU engine, not an M52B28. So I'm wrong all around. lol.

[cjames10]

Wow, thanks for all the responses. I am new to the BMW world, so all advice is appreciated. It sounds like the 1999 M52TUB28 'short block' swap isn't an option


I have worked on plenty of cars in my day but I have never been a heavy modifier. So the LS1 swap is not appealing. Also, I live in the Chicago metro area, so it has to pass emissions testing.


The S52 swap sounds interesting, but that must be a rare motor(expensive). And again emissions concerns.


It sounds like the cast iron M52B28 engine is the best way to go. I have found several available in junkyards and Craigslist for real cheap $250 - $800. I am interested in reliability over performance. So the question is will the cast iron M52B28 directly replace the aluminum M52B28?


I found a thread here where a member suggested its been done.
I have read other threads that the cast iron block is only 52 pounds more.

[Kondata]

emissions testing is easy to bypass. If you decide you never want to wait in line at a emissions station again (or your car may not pass), there's an easy way to exclude yourself from that list.

[zellamay]

In Phoenix, I've seen M52 motors around $800 and S52 motors around $1700. Well worth the $1000 or so for that much power.

[s8ilver]

emissions testing is easy to bypass. If you decide you never want to wait in line at a emissions station again (or your car may not pass), there's an easy way to exclude yourself from that list.

Double post.

[s8ilver]

emissions testing is easy to bypass. If you decide you never want to wait in line at a emissions station again (or your car may not pass), there's an easy way to exclude yourself from that list.

Is this an IL only thing? I'd love to never emissions test again. In CO, you can apply for a waiver if you've spent $715 on emissions equipment and the car still fails. I have no idea how they came up with that number.

[DiqueTico]

Or you can bring it to hackentt and we can see a n54 e36/7.


Sent from my iPhone using Tapatalk

[Tigershark48]

I just registered my newly purchased out of state 2000 roadster in Wisconsin and my DMV identified it as emissions exempt due to its age.

[cjames10]

In Chicago Metro area, cars

after 1996 but not less than 4 model years old

have to be tested.

[cjames10]

Do you have to go to the DMV to apply for exemption?

- - - Updated - - -

Sorry but this is incorrect. The M52TUB28 is a twin VANOS engine and the water flow through the block and head is the reverse of the single VANOS M52B28. You can not use the M52TUB28 block with a M52B28 head.

Go for a complete engine swap. A M52B28 is the easiest. If you go for a M52TUB28, then also get the DME and engine loom. You will need to learn how to align the new DME with the EWS to get the engine started

I found a nice M52B28 cast iron engine out of a 528i. Do you know if this will drop right in without any modifications?

[cjames10]

Here is my Z3 with the bad engine.

[Kondata]

I only know this for IL, possible something like this exists in other states. https://illinoisairteam.net/waivers-...ns-extensions/ is the site to go to and register your car under "sporting vehicle". All you do is give them your VIN, license plate and personal info (address, name and phone number). You get approved within hours and the result is you are removed from the check list of vehicles that require emissions. This has to be renewed every 2-3 years (I forget exactly) and can be done from anywhere. There is no mileage restriction, no special circumstances, nothing. You just go buy a plate sticker like normal without having to pass emissions. Thats it.

[Tim95M3]

In Phoenix, I've seen M52 motors around $800 and S52 motors around $1700. Well worth the $1000 or so for that much power.

You can make near-stock S52 power out of an M52 with a couple hundred bucks... You think "all that power" is worth a grand extra?

[zellamay]

You can make near-stock S52 power out of an M52 with a couple hundred bucks... You think "all that power" is worth a grand extra?

How would you do that?

[Tom Liberatore]

How would you do that?

Yeah, inquiring minds would like more details please!

[Tim95M3]

How would you do that?

My 98 2.8 has an intake, ASC delete, M50 intake manifold and a 3.46 diff. Runs door to door with a buddies stock S52 M roadster that made 215whp on a mustang dyno. And we both have the driver mod. My 2.8 coupe has an M54B30 intake manifold and intake cam, catless ebay headers and a 3.46 diff. Runs fairly even (a little slower) with a buddies stock S52 M coupe. I just don't have the S52 hype like everyone else.

[SteveG66]

That's impressive!! Out of curiosity, what is the driver mod??

My 98 2.8 has an intake, ASC delete, M50 intake manifold and a 3.46 diff. Runs door to door with a buddies stock S52 M roadster that made 215whp on a mustang dyno. And we both have the driver mod. My 2.8 coupe has an M54B30 intake manifold and intake cam, catless ebay headers and a 3.46 diff. Runs fairly even (a little slower) with a buddies stock S52 M coupe. I just don't have the S52 hype like everyone else.

[zellamay]

My 98 2.8 has an intake, ASC delete, M50 intake manifold and a 3.46 diff. Runs door to door with a buddies stock S52 M roadster that made 215whp on a mustang dyno. And we both have the driver mod. My 2.8 coupe has an M54B30 intake manifold and intake cam, catless ebay headers and a 3.46 diff. Runs fairly even (a little slower) with a buddies stock S52 M coupe. I just don't have the S52 hype like everyone else.

"hype"? 50 hp is 50 hp. I had both a 2.8 and the M, both stock except for KN filters, for a few months while I sold the 2.8. No comparison in acceleration (or handling of course). What is an "intake", if more than a KN filter? My 98 M has no ASC, but is not rated any higher than other years. So, it looks like you're getting equivalent of 50 hp from the M50 mod and a slight change in gearing. That's far better than anything I've read about so far.

[nthor71783]

Good oportunity for an LS-1 swap. ;-)

I second the LS swap with a T56 trans! More power and less weight than a BMW 6 cyl. Only down side is a s***ton more work.