M20 Refresher

[Trucidatio]

I am going to be picking up a used good condition m20b25 tomorrow.

I plan on putting about $400 into before I swap it into my 87' 325is.

What all should I do to the engine with that $400.

New seals all around is a given.

I am just going start a list on here. ANy help would be greatlt appreciated.

*Head gasket
*Valve cover gasket
*Rear main seal
*Exhuast manifold Gasket
*Timing Chain (Was jsut recently done to the engine however)
*Spark plugs/ wires
*Vacuum/intake hoses and boots
*Fuel Filter
*o2 sensor
*Fan clutch
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[StereoInstaller1]

Valve guide seals, possibly valve guides, hand lapp the valves...maybe re-ring?

[jlevie]

If you are going to pull the head, definitely do a valve job and seals. But if the engine is of moderate mileage, say less than 150k, I wouldn't bother removing the head unless you suspect that it has a head gasket leak.

I'd add to that list:

Intake manifold gaskets
The four rubber bungs for the valve cover
New seals for the oil return tube
Pan gasket
Timing belt
Cam shaft seal & o-ring
Water pump
Thermostat
All cooling system and intake hoses

Before tearing into the engine, run a leak down test. That will tell a lot about the condition of the cylinders and rings. If the leak down numbers aren't good you could be looking at a hone and re-ring at the least.

[Rolla1990]

Just get a head gasket set and a block gasket set. Those will include every seal you need for around $100. You can spend another $100 at bimmerworld for a complete coolant hose kit, then also get a timing belt kit and water pump. You'll be good to go!

[T Verdier]

remember that the vacuum lines and smog shit is sometimes different on an 87.

[White325is]

Just get a head gasket set and a block gasket set. Those will include every seal you need for around $100. You can spend another $100 at bimmerworld for a complete coolant hose kit, then also get a timing belt kit and water pump. You'll be good to go!

The head gasket sets dont come with valve seals/throttle body gasket/injector seals any more.

Maybe this link will help you..

http://e30tech.com/forum/showthread.php?t=69492

I had 250 into a head job. If you want to spend 1500.00 you can do a full rebuild on an M20 and thats with machine work and all.
Kinda all depends on how deep you want to get into it.
If you just wanna do the basics, than about 600 in parts.

Check out fap99.com for anything you need.

[bmwstephen]

subscribed.

I was thinking about switching my car from running conventional oil to synthetic. I want to know the important seals to replace so that there wont be any leakage from the switch.