NVADER 54 Report post Posted November 24, 2015 These might be noob questions but I can't find answer's solid enough to make me feel comfortable buying this stuff as some of it may come from overseas. Can anyone confirm if the following are interchangeable between the B20 and B25: - Timing Belt - Water Pump - Tensioner Pulley - Alternator/Power Steer Belts - Cam Seal - Thermostat Realoem shows the same part numbers for most of these but this is only the second time I've used it so no idea how accurate it is. Main reason for asking is that there's a huge amount of 'timing belt kits' available for the B25 and bugger all for the B20 Quote Share this post Link to post Share on other sites
NVADER 54 Report post Posted November 24, 2015 Also, aside from the different types of injection, are there differences in these parts between facelift and pfl? Quote Share this post Link to post Share on other sites
E30 325i Rag-Top 2956 Report post Posted November 24, 2015 B20 and B25 parts should be the same, PROVIDED it is a motronic B20 and not an L-jet (pre-facelift). In terms of the parts you have listed, the water pump is definately different from FL to P/fl, and I believe the thermostat is as well. Realoem is pretty accurate, it seems to run off an old version of BMW ETK, but again, just make sure you are comparing with the right version of the B20 engine. Quote Share this post Link to post Share on other sites
actletpone 43 Report post Posted November 24, 2015 There were two different timing belts for the m20 engine, one is 127 tooth the other is 128 tooth. I believe the 128 tooth setup was for older cars and to change to the newer 127 tooth belt you just need the 'z127' stamped tensioner. Early m20's I guess the ones which came with the 128 tooth setup? also had a weaker cam gear 1 Quote Share this post Link to post Share on other sites
Young Thrash Driver 1020 Report post Posted November 24, 2015 Belts/ water pump/ tensioner are interchangeable between facelift B20 and B25 for our NZ spec cars, went through this not long ago with my E30. As above, check for z127 mark on the tensioner- although I believe RealOEM points this out. They keep good track of what part supersedes which, too. Poor availability of B20 timing belt kits reflects that the States never got this engine. Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted November 24, 2015 didnt know there was a difference in belt teeth! 1 Quote Share this post Link to post Share on other sites
NVADER 54 Report post Posted November 24, 2015 didnt know there was a difference in belt teeth!Neither..and the fact that's its different between fl and pre fl would explain why the ones I was looking at on realoem were the same. Unfortunately mines an '85 and it seems to be a weird mix of the two :/ Would've thought you'd be able to adjust the tensioner enough to make up for an extra tooth though Sent from my D6653 using Tapatalk Quote Share this post Link to post Share on other sites
actletpone 43 Report post Posted November 24, 2015 Stock of the 128 tooth belt I assume would be pretty limited now but some foreign websites may still have it listed? Just need to make sure you are using the right tensioner, I guess you could adjust the old one? But if you still have one it is probably due for replacement anyway Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted November 25, 2015 Yep, from memory my E12 has the 128 tooth belt - very early M20. I remember there was a variation when I replaced it years ago Quote Share this post Link to post Share on other sites
NVADER 54 Report post Posted November 26, 2015 Awesome. Thanks for the help Quote Share this post Link to post Share on other sites
