New project! m20 head replacement

[HighschoolE30]

So today i picked up a 89 325i with 112k on it for $900.

Down side is that it over heated and cracked the head. So the heads going to need to be replaced. Question being, what all am i going to need to do this, figured i'd need a timing belt kit and water pump as well. Since its all apart.

Haven't messed with M20's very much, always had my M42. So any help is appreicated.

[Tree25]

IE has an upper gasket kit for the m20, it covers all gaskets that you'll need to replace when pulling the head off. They run about 90 bills

[jlevie]

The first action should be to pull the head and have it checked by a machine shop for cracks. It may be that the head just warped during the overheat. If which case it can be surfaced. If the head is cracked and has to be replaced, have the replacement head checked. In almost all cases I find that a used head has some warp and a light surfacing cut is needed. A the least a used head should have the valve seals, cam seal, and o-ring replaced and it should have the valves ground and the cam checked for wear.

To install the head on the engine you will need:

New head bolts
New exhaust manifold and header nuts
Head gasket
Intake, exhaust, and header to down pipe gaskets
Oil return tube seals
Thermostat and heater nipple gaskets
Valve cover gasket & the four rubber bungs
Thermostat
Water pump
Timing belt & tensioner

Since this engine has overheated (and since the parts are old) I would also replace:

Radiator, expansion tank & cap
All cooling system hoses
Fan clutch
Oil breather hose
Injector seals

Rather than just replacing the injector seals I would send the injectors off to have them cleaned and flow tested. They will come back with new seals.

You may find that the nipples on the thermostat housing are severly corroded. In which case a new thermostat housing is indicated. The current production housing has two extra threaded holes in this application and you will need the plugs & sealing washers for those and the temp sensors.

[HighschoolE30]

Thanks guys for all the input. All very helpful. I'm excited as hell to pick my new project.