the m20 is generally a tough engine and as long as it's seen a few oil changes and the belt doesn't break you can get well over 200k miles without any problem at all. mobil one (the oil company) did a cool test many years ago, they took a brand new 87 325ism and put it on a roller dyno and ran it in real world type conditions with all synthetic fluids, the tranny died around 600k miles and they tore the motor down at 1,000,000 miles and it was still in factory spec on all surfaces, i can't remember how much further they ran it after reassembly, it was several hundred thousand more miles before they gave up trying to wear it out

Originally Posted by
nsbone_1988_520i
Hi, I have an offer an M20B25 (motronic) engine just the engine block with internals and head for RM1800 (US$460) with warranty or RM1200 (US$310) without wrranty.
From the outside, the engine looks pretty ok. I have yet to open the oil cap on the head and see if the cam is reasonably looks good.
Question:
- How often M20B25 frm a junkyard (scrapped 525i imported from Japan) can go bad?
- Would i take too much risk, as i could loose the USD310 for nothing? Or is the risk is worth it?
- or i should spend the additional US$150 for warranty/replacement if the engine block/head could be a bad one...
Appreciate for any opinion...
all america wants is cold beer warm cat and a place to take a poop with a door on it