M50 questions...

[Suspence]

Looking to purchase a car with a swapped in M50, it's an 89 325i. Head gasket was re done, new coolant system, new fuel pump, 160k miles.

Anything I should watch out for? I plan on probably doing s52 cams and doing some nice work to the motor once I get the car. I have my car that I might swap over parts with. Then TURBOO :)

M50 seems like a better motor to do a turbo build on, plus it's more power out the gate. Any tips and advice is MUCH appreciated.

Thanks!

[scottinAZ]

check the same things that you would with an M20 engine and trans wise. Check to see if the owner has receipts for the work done and parts purchased. this will help build good feelings as to whether the swap was done half-assed or if the owner knew what he was doing and did it right.

[samiam3356]

look for leaks where the tranny and block meet. rear main usually bad.
Look for leaks in general
timing chain motor so no issues usually there
Vanos - make sure its not making noises
if you can, do a compression test or leak down test

just a few that come to mind

[Adrian_Visser]

check the same things that you would with an M20 engine and trans wise. Check to see if the owner has receipts for the work done and parts purchased. this will help build good feelings as to whether the swap was done half-assed or if the owner knew what he was doing and did it right.

Not really the same maintenance items, TBH. No timing belt to worry about on an m50 and no valve adjustments to be done.

Cooling system components are the main issue with m5x motors, check that it has a metal thermostat housing and a metal impeller water pump and that all the hoses and thermostat are newish.

What is it running for a cooling fan?

Lifter tick and timing chain noise are other things to watch out for.

As for the swap itself definitely have a look at how the work was done, if it looks half ass on the surface chances are it gets worse than first glance.

Make sure the CEL works and that it isn't flashing any codes, also check that there is power to the diagnostic connector so that you can run a Peake scan tool.

Is the wiring done with an adapter or is the c101 hardwired onto the harness?

Does the oil level sensor work?

Obviously a compression/ leakdown test wouldn't hurt.

How is the idle when COLD?

[Danny]

Wiring.

[Dj Buttchug]

lol^

[MR 325]

Agreed on the wiring. Definitely the scariest part of swap cars. For some reason people think it's hard to do things the RIGHT way.

[ak-]

I'll make it easy and affordable for you:

http://www.r3vlimited.com/board/showthread.php?t=220870

[328ijunkie]

+1 Wiring.

[kingston]

S52 cams won't work on an M50, just FYI...

***EDIT*** Unless you swap cam trays...

[328ijunkie]

Yes they will if you swap trays.

[kingston]

Yes they will if you swap trays.

Really? I learned something new today! editing my above post...

[328ijunkie]

More fun facts, m50/s50 cams are "small" and thus have small trays. Obd2 cams (m52/s52) have "big" cams. Thus m50/s50's will go into any motor. M52s and s52s require "big" cam trays so if you want to use them in a "small" cam car you just have to swap the trays over.