'87 325i Broken Rocker Arm

[clhorton]

So I'm driving my newest addition, an '87 325ic, on the interstate and when I come to a stop I hear it missing. I make it to my destination and find that the inake rocker arm on the first cylinder (closest to the radiator) has broken in half and the valve, of course, is not opening. Is it possible to change that rocker arm without having to remove the head. If removing the head is my only option, can I get away with removing the head and not changing the head gasket. The engine has an excess of 230k and I'm waiting to put a rebuilt unit in it anyways. So what do you guys think? Thanks in advance!

[Barney Paull-Edwards]

you have to ask yourself why the rocker broke. The best answer I can suggest is a seized valve guide, unbolt the rocker and see if the valve will move against the spring,it may have seized with heat,if stuck ,its head off time and dont even think of re-using the gasket.If free try lifting the seal and dribbling oil down the shaft and assembling with a new/old rocker, you might get away with it.

[Rigmaster]

Common problem on higher mileage M20's.

Pull the head, change ALL the rockers- unless there is a compelling reason not to. You will need a new head gasket- they're not too expensive, IIRC a complete head gasket set is ~$90.

BMW has a revised rocker arm for the M20, came out probably 10-12 years ago, so all new rockers should be the "new" style and less likely to break. If one broke, chances are others are not too far behind.

230k is not too much on the bottom end, just pull the head, have a look at the cyl walls- you will probably be able to see crosshatching marks. If so, I'd just redo the head and reinstall and you should be good for another 100k.

Good used M20's are cheap, maybe $500-600, so if there is any reason to suspect other problems, just go with a complete used engine.

Bret.