how to change intake manifold gasket M20B25?

[2.5-12]

the gasket is cheap, the tools aren't a problem and I have time

I just want to know what is really involved in this and if its difficult or not?

1.)what all needs to come off?
2.)how long should I budget for this? (I have done lots of wrenching on my other cars but none on a E30 or M20 at this point)
3.)what else should be done while I'm in there?


I'm doing new injectors at the same time, any advantage to buying injectors for the 3.4 liter M30 over the 2.5 liter M20 injectors (same price)

Thanks much!
-Erik

[Schnitzer318is]

Having just done this... it is not fun. Not hard, just can be frustrating getting to the 12 12mm nuts on the intake. I could not have done it without u-joint ratchet accessories so that I could attack from different angles. Since you haven't done it before... budget around 2 hours to remove and reinstall it.

As far as replacing stuff while you're under there... check the condition of vacuum lines and the coolant lines that are hard to get to under it. Other than that you should be fine.

[2.5-12]

luckily I have a u-joint, lots of shallow and deep sockets and I easily have 2 hours to devote

other than the airbox, bracket that holds the IM to the Valve cover and the bolts that hold the Im to the engine, any odd socket or tool needed?

is the FEL-PRO gasket from rock auto fine? I cant seem to find anything else for the M20B25 but Tons for the M20B27

Thanks,

[jlevie]

No special tools other than sockets, a flx joint, and extension are needed. The only tricky part is that you have to push the oil return tube down into the engine to get the intake off or on. A zip tie or wire on the oil return tube spring is needed if you don't have a helper. Oh yeah, replace the seals on that tube. The brand of intake gasket isn't all that important. Just be sure to fully clean both surfaces.

There's no real advantage to other than the stock injectors if the rest of the fuel system is operating as it is supposed to be.

[Dirtbleed]

you have to take all this off.
I bought a brand new thermostat housing and gasket, a throttle body gasket, coolant temp sensor, as well as the intake gaskets, also removed a bunch of plumbing from the cooling system and a new starter. And if your ever gone do a starter it's the right time.

[2.5-12]

where is the oil return tube on the M20? I am assuming below the IM somewhere

what all is needed to push that into the engine and i'd imagine I'll be able to figure out how to strap it up while I am replacing the gasket.

I'll just get the standard blue top injectors.

[Dirtbleed]

then cleaned it

[2.5-12]

I hadn't intended on doing my thermostat until I do my timing belt in the spring, I guess I'll be buying a new gasket for the housing now then get the whole housing kit in the spring.

[2.5-12]

great pics ^ :)

[Dirtbleed]

also maybe get new o-rings for the oil return tube. it's a washer and an o-ring on both ends. when I took mine apart the washer was missing. hence the oil all over the place. now it's bone dry from that tube.

[2.5-12]

the oil return tube is the 7th hole between zyl 3 and 4?

I'll make sure to pick up those gaskets before I dig in

I'm glad to see I can leave the thermostat housing in place while I do this

[Ruffian]

the oil return tube is the 7th hole between zyl

No. The oil return tube runs between the intake and the spot i have rudamentarily circled from dirtbleeds picture. It's basically the pipe you see under the intake if you look at it now. spring on the bottom keeps pressure against a rubber oring at the top, and then there's a oring at the bottom as well, kept in place again with the spring pressing against a flat washer. The tube is longer at the bottom so it extends into the block. You'll see this when you begin.

Even for a novice, this is a fairly easy job as it's all up top. I would definitely have a bentley in hand though.

[2.5-12]

ah, that makes more sense - I'm sure its something I'll have to see to understand - hopefully I can source a new gasket quickly assuming I can figure out how to push the tube correctly

I have a .pdf manual but it sucks and doesnt cover this job, local places sell every other car's manual it seems but no one carries the haynes or bentley manual locally it seems.

got the gasket in yesterday, hope to start this weekend if all goes well

[Hallen]

Make sure you get ALL the old gasket material off of the engine and intake manifold. If you miss some of it, it is very easy to crack the intake manifold when you tighten down the nuts. That surface has to be very level when the manifold is tightened down. It doesn't take much, so be very sure that it is all gone. Old gasket can blend in with the engine so it can be hard to see.

[2.5-12]

I'll try to make sure of that

whats the torque number on the intake manifold nuts?