m52 cylinder head

[mini1380cc]

Looking for some advice please. I have a 523i that is in the garage for head gasket failure and they seem to think the head will fail a pressure test. I'm researching the possibilities of replacing the head but all i can find is the m52 head that fits the 528i. Are these one and the same?

Secondly do you think it would be cheaper to replace the head and all the work that goes into it, or should i just source a whole new engine and drop it in? Will a 528i engine plug and play in a 523i?

Any advice appreciated.

Mini1380cc

[TheEnd]

They might be expecting a cracked head.

As it's an alloy block, they do also sometimes strip the threads out just as you're about to get to the final torque.

You might be better off swapping a complete good engine rather than getting a refurbed head, and hoping it won't strip too.

[phelix]

If you do decide to go down the swapped head route I've read that it's sensible to loosen the head bolts and then immediately retorque them to spec - if they strip you know your block will either need helicoils or replacing and you find out before you've gone any further.

You might wish to do some searching on bmwfans.info to see if the 523i and 528i share the same air mass sensor, injectors, throttle valve, manifolds, etc before going too far with an engine upgrade.

[BountyHunter]

TheEnd said:

As it's an alloy block, they do also sometimes strip the threads out just as you're about to get to the final torque.

if its overheated then its more usually than sometimes

[mini1380cc]

Thanks for the advice guys. I'll wait and see how the pressure test goes, then decide from there. Should have bought a 540