Junkyard m50?

[noE30]

My local junkyard usually doesn't have any bmws and just recently they got a 94 325i in. I've always wanted to do a dohc swap and I've been thinking about picking up this m50 to slowly rebuild/ build up and then swap in my e30 eventually. What should I look into about this engine? To see if its worth it?
Its a 94 325i sedan with an auto trans. Looks to be totally complete, so I could get the dme, harness, engine, and mounts.
Thanks for the help.

[herlsy]

Well first thing to note would be whether the car has any major body damage, this is the best indicator of why the car ended up in the junkyard in the first place.

If the car is pretty straight as far as the body/chassis goes, it's a good indicator the motor might be toast.

I personally took a chance on one in my local junkyard, car wasn't wrecked so i knew i'd be doing an overhaul on the motor. Couldn't pass up a complete motor with everything for 176 bucks. Blown head gasket for sure, slightly warped head, but the rest of the internals were great.

I'd recommend a partial breakdown, maybe removing the head and oil pan to check things a bit more thoroughly.

[Jean]

Or it could be there because it's got a broken auto. See if you can still start it and go from there..

[noE30]

The body looks pretty straight too, the guy that runs the junkyard said that the owner of the e36 replaced the radiator and then the car wouldn't start afterward so he junked it. My first thought was that maybe it overheated that's why it woudn't start.

[Jean]

If it's only a few hundred for a complete motor, just buy it and rebuild it in your spare time.... since you'll need a different pan so you'll end up inspecting bottom end anyway.

[noE30]

If it's only a few hundred for a complete motor, just buy it and rebuild it in your spare time.... since you'll need a different pan so you'll end up inspecting bottom end anyway.

That's kinda what my plan was. I just did a bunch of maintenance on my m20 so I don't really want to swap the engine right away. Maybe in a year or so..

[flyboyx]

well....from a financial standpoint, you are much better off spending 8 or 900 for a good running engine than getting a free bad one that needs rebuilding-even if you do 75% or more of the work yourself. assuming that you have good mechanic skills, you would potentially wind up with an almost new engine. to do it correctly, it will cost you about the same as you would pay for a good used s50/52. plan 1500 to 2000.00 or more for a complete rebuild with machine work (depending on what it needs). in fact, you would be better off buying a bad s52 to rebuild because the work and parts are about the same price. if nothing else, do a compression check or as a last resort pull off the head. if all six cylinders and the bottom side of the head look clean, buy it. if not take my advice and go look somewhere else.

as an example, a couple of weeks ago i purchased a complete 93 m50 so i can use it as a mock up for installing an s52 in an ix. i paid 175 complete with harness, intake, accessories, and dme. i know that i won't get hurt on it for that price, but i was hoping to resell the head and a few other parts to recoupe my costs. to make a long story short, i removed the head a couple of days ago.....4 of the 6 cylinders are are scored really bad. two of the pistons have part of the crown eaten away from ?detonation? on the exhaust side. on the head those four cylinders also have a pretty good amount of aluminum eaten away between the exhaust valves. one of the exhaust valves in cylinder 6 actually has a good size notch burned into it. if that isn't bad enough, the oil was full of mayonnaise. basically, this motor is fucked and not rebuildable. it will suit the purpose i intended it for. the obd 1 parts are worth what i paid. however, if i intended to purchase this boat anchor to rebuild, i would be really pissed.


if you do have to pull off the head, you will need to buy a special socket for the 14 head bolts and another special socket for the three small head bolts under the cam gears. that little socket will also be needed to remove the exhaust cam gear. removing this gear and chains is a pain but you will need to do so to get the head off. it is an even bigger hassle to get all of that back together correctly unless you have some fairly expensive special tools.

the cheapest way to do what you want would be to go find a wrecked 93 or 94 525i with great compression. pretty much everything you need will be there except the motor mount brackets. after this long dissertation, what i am saying is that if the engine is less than 200.00, it might be worth it. however, you need to buy it with the intention you are just buying parts. not to discourage you, but since it is in a junk yard, chances are about 8.5 out of 10 that it is probably a piece of crap.

[noE30]

I completely understand what you're ^ trying to say. Next time I'm out there I'll ask what they want for it, that will give me a better idea on what I should do. The only issue with buying this m50 is that if I were to do a swap I would much rather swap an m52 or s50, so maybe I'll just wait for one of those to pop up.

[SiGmA_X]

FWIW, it was ~800 w/ machine work and self-assembly to rebuild the bottom end of my stock M50, and only put new valve seals in the top end. It would have been ~$240 more for valve guides at my machine shop. Zero need to do seats on my motor at 170k, the surface is perfect and well within spec width.

I'd suggest getting a well running lower mile M50 from an e36 and swap the pan. It'll be the easiest/best option.

[noE30]

I might have found an engine on craigslist. m50 for 200, complete with wiring harness. I really want to try pick this up but I'm busy for the next few weeks, so I might see if he can hold on to it.

[e30s50dan]

Yea if it's from a 5 series you can't go wrong for 2 bills you will pay that much for the pan. I just bought a S50 and brought it home only to find out the leakdown readings sucked so off came the head and had it rebuilt back together and ready to go in

[619E30]

Just buy it and rebuild it, so then you'll know you wont need to rebuild it for another 80,000 miles ;)

[noE30]

Just buy it and rebuild it, so then you'll know you wont need to rebuild it for another 80,000 miles ;)

Yeah I want to just mount it on a stand in my garage and rebuild it over the next year and then swap it.