marchant.oliver 1 Report post Posted January 15 (edited) Hi there, Pretty new to the forum and just wondering if anybody has any takes on this. I've got a 325i touring and my M52 engine has high KMs for a BMW and is deteriorating quickly, I've been planning on making more power out of it but I'm not sure whether its worth spending the time and money on upgrading and maintaining the older engine or swapping to something newer that will have less wear and issues. Either way its going to be a project that will take some time and wondering what upgrade options people know are worth it for M52s or any other BMW engines that would be worth swapping to that would fit. Edited January 15 by marchant.oliver Quote Share this post Link to post Share on other sites
Vass 832 Report post Posted January 15 First thing I'd do is figure out what engine you actually have as something doesn't seem to add up from what you've said there. If it's a 325i then it will have an M54B25. If as you say it's got an M52 then it'll be a 323i or a 328i. Both M52's & M54's are relatively solid engines and can easily reach 400,000km's without needing major rebuilds but by this point all of them are likely to have various issues, from minor stuff like oil leaks to oil burning, failing coils, VANOS & DISA units etc. If you feel your current engine deteriorating then it could just be some long term maintenance items needing addressing. In terms of swaps, depends on how involved you want the project to be. Easiest and cheapest would be to drop in a plug & play M54B30 which is the biggest engine that came in these from factory and would give a moderate power boost. Other, more involved options that would require custom fabrication and indepth wiring shenanigans would be to swap in an M62 V8 or similar, or do an absolute madness and go B58. Or just turbo the engine you already have. Quote Share this post Link to post Share on other sites
marchant.oliver 1 Report post Posted January 17 Sorry about that one got mistaken with what engine i’ve got 🤣. Just done a rundown of the issues on mine and i’ve got moisture / contaminants mixed into my oil which has created that brown sludge so thinking it’s a head gasket but not worth cleaning out and sorting that + other minor issues if a new engine is coming soon. I don’t think that my skills are quite up to a super custom engine setup so the m54b30 sounds like a good swap, it’s a bit of a learning experience as i’ve done other mechanical work but at my skill level I reckon a plug and play swap i’d be able to do and mod after that for extra power. Cheers for the recommendations Quote Share this post Link to post Share on other sites
Vass 832 Report post Posted January 17 How many k's has it got on the clock? Head gasket failures are fairly rare on M52/M54's, unless well abused and/or severely overheated. The milkshake in the oil could be something as simple as a clogged up CCV system, which is a pretty common occurance and one of the most commonly neglected maintenance items so that'd be the first item I'd address before jumping to a conclusion of a failed head gasket. Worth getting either way as you could just reuse it if you do end up going for an engine swap. Milky residue could also be caused by repeated short drives where the engine doesn't fully warm up so the moisture doesn't get a chance to escape. I've done an M54B25 to M54B30 swap on my wagon and the difference in power is noticeable, although not mind blowing. As far as squeezing more power out of it though, unless you go the forced induction route then the options are fairly limited. These engines are tuned pretty well close to their potential in naturally aspirated form from factory. Slapping on a pod filter is the most common mod but is more likely to lose you power as the stock air box is actually quite well designed. You could make some gains by opening up the exhaust a bit more but there aren't any budget options for catless headers for RHD cars so it quickly becomes a custom fabrication exercise and you'd maybe hope to gain all of 10hp. Aftermarket cams, ECU remaps, stroker kits, ITB's are options but none of those are cheap or simple and gains will be quite modest still. Quote Share this post Link to post Share on other sites
Kodachrome 151 Report post Posted January 18 FWIW, for my M54B30 swap (from a M30B25, so a big change) I got a custom retuned (though BMW original) ECU from this US company that combined with a wiring loom harness adapter for my E28 made the swap fairly plug and play: https://www.redline-motorsport.com/product/ms43-tuning/ Quote Share this post Link to post Share on other sites
